Investigator

P. M. Webb

Group Leader · QIMR Berghofer Medical Research Institute, Population Health

PMWP. M. Webb
Papers(12)
‘Hit me like a brick …Patterns of Associati…Green tea consumption…Cellular origins of m…Long-acting, progesti…Use of menopausal hor…Risk Factors for Ovar…Mismatch repair statu…Global epidemiology o…Mental health and die…Coffee consumption an…Diet and survival aft…
Collaborators(10)
Susan J JordanRenhua NaAnna DeFazioJennifer A. DohertyFrancesmary ModugnoNicolas WentzensenUsha MenonPaul D P PharoahSusan J RamusHolly R. Harris
Institutions(9)
The University Of Que…The University of Syd…University of UtahUniversity Of Pittsbu…Division Of Cancer Ep…University College Lo…Cedars-Sinai Medical …University of New Sou…Fred Hutch Cancer Cen…

Papers

Patterns of Associations with Epidemiologic Factors by High-Grade Serous Ovarian Cancer Gene Expression Subtypes

Abstract Background: Ovarian high-grade serous carcinomas (HGSC) comprise four distinct molecular subtypes based on mRNA expression patterns, with differential survival. Understanding risk factor associations is important to elucidate the etiology of HGSC. We investigated associations between different epidemiologic risk factors and HGSC molecular subtypes. Methods: We pooled data from 11 case–control studies with epidemiologic and tumor gene expression data from custom NanoString CodeSets developed through a collaboration within the Ovarian Tumor Tissue Analysis consortium. The PrOTYPE-validated NanoString-based 55-gene classifier was used to assign HGSC gene expression subtypes. We examined associations between epidemiologic factors and HGSC subtypes in 2,070 cases and 16,633 controls using multivariable-adjusted polytomous regression models. Results: Among the 2,070 HGSC cases, 556 (27%) were classified as C1.MES, 340 (16%) as C5.PRO, 538 (26%) as C2.IMM, and 636 (31%) as C4.DIF. The key factors, including oral contraceptive use, parity, breastfeeding, and family history of ovarian cancer, were similarly associated with all subtypes. Heterogeneity was observed for several factors. Former smoking [OR = 1.25; 95% confidence interval (CI) = 1.03, 1.51] and genital powder use (OR = 1.42; 95% CI = 1.08, 1.86) were uniquely associated with C2.IMM. History of endometriosis was associated with C5.PRO (OR = 1.46; 95% CI = 0.98, 2.16) and C4.DIF (OR = 1.27; 95% CI = 0.94, 1.71) only. Family history of breast cancer (OR = 1.44; 95% CI = 1.16, 1.78) and current smoking (OR = 1.40; 95% CI = 1.11, 1.76) were associated with C4.DIF only. Conclusions: This study observed heterogeneous associations of epidemiologic and modifiable factors with HGSC molecular subtypes. Impact: The different patterns of associations may provide key information about the etiology of the four subtypes.

Green tea consumption, primary treatment outcome and survival after a diagnosis of ovarian cancer

Background Drinking green tea prior to a diagnosis of ovarian cancer has been associated with improved survival; however, research on post-diagnosis consumption is limited. We investigated whether consuming green tea during primary chemotherapy was associated with improved treatment response and whether green tea drinking pre-diagnosis or post-treatment was associated with survival. Methods We used data from the Ovarian Cancer Prognosis and Lifestyle study, an Australian prospective cohort of 958 women with epithelial ovarian cancer. Tea consumption was self-reported at baseline and at 3 monthly intervals following diagnosis. Logistic regression was used to estimate ORs and 95% CIs for the association between green tea consumption during primary treatment and outcome. Flexible parametric survival models were used to estimate HRs and 95% CIs for the associations between green tea pre-diagnosis and post-treatment and survival. Black and herbal tea were included as negative controls. Results No association was seen between green or black tea consumption during chemotherapy and treatment response. There was a suggestion that drinking at least one cup/day of green tea in the pre-diagnosis or post-treatment periods was associated with improved overall survival (pre-diagnosis: HR=0.78, 95%CI=0.60 to 1.00; post-treatment: HR=0.84, 95%CI=0.66 to 1.04), but not progression-free survival. Conversely, herbal tea consumption post-treatment was associated with improved progression-free but not overall survival. Conclusions We confirmed previous results suggesting green tea may be associated with better ovarian cancer survival but cannot rule out the possibility that residual confounding may be influencing these associations. Randomised trials are required to confirm any potential benefit.

Long-acting, progestin-based contraceptives and risk of breast, gynecological, and other cancers

Abstract Background Use of long-acting, reversible contraceptives has increased over the past 20 years, but an understanding of how they could influence cancer risk is limited. Methods We conducted a nested case-control study among a national cohort of Australian women (n = 176 601 diagnosed with cancer between 2004 and 2013; 882 999 matched control individuals) to investigate the associations between the levonorgestrel intrauterine system, etonogestrel implants, depot-medroxyprogesterone acetate and cancer risk and compared these results with the oral contraceptive pill. We used conditional logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI). Results Levonorgestrel intrauterine system and etonogestrel implant use was associated with breast cancer risk (OR = 1.26, 95% CI = 1.21 to 1.31, and OR = 1.24, 95% CI = 1.17 to 1.32, respectively), but depot-medroxyprogesterone acetate was not, except when used for 5 or more years (OR = 1.23, 95% CI = 0.95 to 1.59). Reduced risks were seen for levonorgestrel intrauterine system (≥1 years of use) in endometrial cancer (OR = 0.80, 95% CI = 0.65 to 0.99), ovarian cancer (OR = 0.71, 95% CI = 0.57 to 0.88), and cervical cancer (OR = 0.62, 95% CI = 0.51 to 0.75); for etonogestrel implant in endometrial cancer (OR = 0.21, 95% CI = 0.13 to 0.34) and ovarian cancer (OR = 0.76, 95% CI = 0.57 to 1.02); and for depot-medroxyprogesterone acetate in endometrial cancer (OR = 0.21, 95% CI = 0.13 to 0.34). Although levonorgestrel intrauterine system, etonogestrel implant and depot-medroxyprogesterone acetate were all associated with increased cancer risk overall, for etonogestrel implant, the risk returned to baseline after cessation, similar to the oral contraceptive pill. We were unable to adjust for all potential confounders, but sensitivity analyses suggested that adjusting for parity, smoking, and obesity would not have materially changed our findings. Conclusion Long-acting, reversible contraceptives have similar cancer associations to the oral contraceptive pill (reduced endometrial and ovarian cancer risks and short-term increased breast cancer risk). This information may be helpful to women and their physicians when discussing contraception options.

Use of menopausal hormone therapy before and after diagnosis and ovarian cancer survival—A prospective cohort study in Australia

AbstractMenopausal hormone therapy (MHT) use before ovarian cancer diagnosis has been associated with improved survival but whether the association varies by type and duration of use is inconclusive; data on MHT use after treatment, particularly the effect on health‐related quality of life (HRQOL), are scarce. We investigated survival in women with ovarian cancer according to MHT use before and after diagnosis, and post‐treatment MHT use and its association with HRQOL in a prospective nationwide cohort in Australia. We used Cox proportional hazards regression to estimate hazard ratios (HR) and 95% confidence intervals (CI) and propensity scores to reduce confounding by indication. Among 690 women who were peri‐/postmenopausal at diagnosis, pre‐diagnosis MHT use was associated with a significant 26% improvement in ovarian cancer‐specific survival; with a slightly stronger association for high‐grade serous carcinoma (HGSC, HR = 0.69, 95%CI 0.54–0.87). The associations did not differ by recency or duration of use. Among women with HGSC who were pre‐/perimenopausal or aged ≤55 years at diagnosis (n = 259), MHT use after treatment was not associated with a difference in survival (HR = 1.04, 95%CI 0.48–2.22). Compared to non‐users, women who started MHT after treatment reported poorer overall HRQOL before starting MHT and this difference was still seen 1–3 months after starting MHT. In conclusion, pre‐diagnosis MHT use was associated with improved survival, particularly in HGSC. Among women ≤55 years, use of MHT following treatment was not associated with poorer survival for HGSC. Further large‐scale studies are needed to understand menopause‐specific HRQOL issues in ovarian cancer.

Risk Factors for Ovarian Cancer by BRCA Status: A Collaborative Case-Only Analysis

Abstract Background: Women with an inherited pathogenic variant in BRCA1 or BRCA2 have a greatly increased risk of developing ovarian cancer, but the importance of behavioral factors is less clear. We used a case-only design to compare the magnitude of associations with established reproductive, hormonal, and lifestyle risk factors between BRCA mutation carriers and noncarriers. Methods: We pooled data from five studies from the Ovarian Cancer Association Consortium including 637 BRCA carriers and 4,289 noncarriers. Covariate-adjusted generalized linear mixed models were used to estimate interaction risk ratios (IRR) and 95% confidence intervals (CI), with BRCA (carrier vs. noncarrier) as the response variable. Results: IRRs were above 1.0 for known protective factors including ever being pregnant (IRR = 1.29, 95% CI; 1.00–1.67) and ever using the oral contraceptive pill (1.30, 95% CI; 1.07–1.60), suggesting the protective effects of these factors may be reduced in carriers compared with noncarriers. Conversely, the IRRs for risk factors including endometriosis and menopausal hormone therapy were below 1.0, suggesting weaker positive associations among BRCA carriers. In contrast, associations with lifestyle factors including smoking, physical inactivity, body mass index, and aspirin use did not appear to differ by BRCA status. Conclusions: Our results suggest that associations with hormonal and reproductive factors are generally weaker for those with a pathogenic BRCA variant than those without, while associations with modifiable lifestyle factors are similar for carriers and noncarriers. Impact: Advice to maintain a healthy weight, be physically active, and refrain from smoking will therefore benefit BRCA carriers as well as noncarriers.

Mental health and diet quality after primary treatment for ovarian cancer

AbstractAimsTo investigate anxiety and depression after primary treatment for ovarian cancer in relation to diet quality and intake.MethodsIn a cohort of women with ovarian cancer in Australia, levels of anxiety and depression (normal, subclinical, and clinical) were assessed using the Hospital Anxiety and Depression Scale at 9 months post‐diagnosis. Dietary intake was assessed using a validated food frequency questionnaire at 12 months post‐diagnosis and scored using the Healthy Eating Index 2015. Multinomial logistic regression and bivariate analyses were used to investigate relationships between levels of anxiety and depression and subsequent diet quality and intake of food groups.ResultsOf 595 women, anxiety and depression were identified among 128 (21%) and 80 (13%) women, respectively. Compared to women without anxiety or depression, women with subclinical anxiety (odds ratio = 0.49, 95% confidence interval: 0.25–0.98) and those with clinical depression (odds ratio = 0.25, 95% confidence interval: 0.07–0.93) were less likely to score in the highest quartile for diet quality. Separate adjustment for age, education, employment, disease stage, body mass index, and smoking status did not attenuate these associations. In bivariate analyses, women with subclinical anxiety were more likely to report higher intakes of sweet foods. Those with clinical depression were more likely to report lower intakes of orange vegetables and wholegrains, higher intakes of sweetened beverages, and not consume alcohol or soya foods.ConclusionsAnxiety or depression after primary treatment for ovarian cancer may be associated with poorer diet quality. Efforts to improve diet quality post‐treatment should consider support for mental health.

Coffee consumption and risk of endometrial cancer: a pooled analysis of individual participant data in the Epidemiology of Endometrial Cancer Consortium (E2C2)

Epidemiologic studies suggest that coffee consumption may be inversely associated with risk of endometrial cancer (EC), the most common gynecological malignancy in developed countries. Furthermore, coffee consumption may lower circulating concentrations of estrogen and insulin, hormones implicated in endometrial carcinogenesis. Antioxidants and other chemopreventive compounds in coffee may have anticarcinogenic effects. Based on available meta-analyses, the World Cancer Research Fund (WCRF) concluded that consumption of coffee probably protects against EC. Our main aim was to examine the association between coffee consumption and EC risk by combining individual-level data in a pooled analysis. We also sought to evaluate potential effect modification by other risk factors for EC. We combined individual-level data from 19 epidemiologic studies (6 cohort, 13 case-control) of 12,159 EC cases and 27,479 controls from the Epidemiology of Endometrial Cancer Consortium (E2C2). Logistic regression was used to calculate ORs and their corresponding 95% CIs. All models were adjusted for potential confounders including age, race, BMI, smoking status, diabetes status, study design, and study site. Coffee drinkers had a lower risk of EC than non-coffee drinkers (multiadjusted OR: 0.87; 95% CI: 0.79, 0.95). There was a dose-response relation between higher coffee consumption and lower risk of EC: compared with non-coffee drinkers, the adjusted pooled ORs for those who drank 1, 2-3, and >4 cups/d were 0.90 (95% CI: 0.82, 1.00), 0.86 (95% CI: 0.78, 0.95), and 0.76 (95% CI: 0.66, 0.87), respectively (P-trend 25 kg/m The results of the largest analysis to date pooling individual-level data further support the potentially beneficial health effects of coffee consumption in relation to EC, especially among females with higher BMI.

Diet and survival after a diagnosis of ovarian cancer: a pooled analysis from the Ovarian Cancer Association Consortium

Prognosis after a diagnosis of invasive epithelial ovarian cancer is poor. Some studies have suggested modifiable behaviors, like diet, are associated with survival but the evidence is inconsistent. This study aims to pool data from studies conducted around the world to evaluate the relationships among dietary indices, foods, and nutrients from food sources and survival after a diagnosis of ovarian cancer. This analysis from the Multidisciplinary Ovarian Cancer Outcomes Group within the Ovarian Cancer Association Consortium included 13 studies with 7700 individuals with ovarian cancer, who completed food-frequency questionnaires regarding their prediagnosis diet. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CI) for associations with overall survival were estimated using Cox proportional hazards models. Overall, there was no association between any of the 7 dietary indices (representing prediagnosis diet) evaluated and survival; however, associations differed by tumor stage. Although there were no consistent associations among those with advanced disease, among those with earlier stage (local/regional) disease, higher scores on the alternate Healthy Eating Index (aHR quartile 4 compared with 1 = 0.66, 95% CI: 0.50, 0.87), Healthy Eating Index-2015 (aHR: 0.75; 95% CI: 0.59, 0.97), and alternate Mediterranean diet (aHR: 0.76; 95% CI: 0.60, 0.98) were associated with better survival. Better survival was also observed for individuals with early-stage disease who reported higher intakes of dietary components that contribute to the healthy diet indices (aHR for Q4 compared with Q1: vegetables 0.71; 95% CI: 0.56, 0.91), tomatoes (aHR: 0.72; 95% CI: 0.57, 0.91) and nuts and seeds (aHR 0.71; 95% CI: 0.55, 0.92). In contrast, there were suggestions of worse survival with higher scores on 2 of the 3 inflammatory indices and higher intake of trans-fatty acids. Adherence to a more healthy, less-inflammatory diet may confer a survival benefit for individuals with early-stage ovarian cancer.

Use of an emulated trial to investigate the association between use of nitrogen-based bisphosphonates and risk of epithelial ovarian cancer

Abstract Background Epithelial ovarian cancer (EOC) is the eighth most common cancer in women, with poor survival outcomes. Observational evidence suggests that nitrogen-based bisphosphonate (NBB) use may be associated with reduced risk of EOC, particularly the endometrioid and serous histotypes; however, confounding by indication is a concern. An alternative approach to investigate the chemo-preventive potential of NBBs is to emulate a target trial by identifying all women who initiate use of NBBs and investigate the risk of EOC for continued users compared with discontinued users. Methods Using population-based linked data, we identified all Australian women aged over 50 years who first used NBBs over 2004–12. We used the year after first use to define treatment for each woman as either continued or discontinued use. We emulated randomization using stabilized inverse probability weights to balance the treatment groups using covariates including age, comorbidities and socioeconomic status. We followed women from treatment assignment until EOC diagnosis, death or 31 December 2013. We assessed the risk of EOC (overall and by histotype) using flexible parametric time-to-event models allowing for time-varying effects, and produced time-varying coefficients. Results Of the 313 383 women in the study, 472 were diagnosed with EOC during follow-up (261 serous EOC), with an average age at diagnosis of 72 years. Continued use of NBBs was associated with reduced risk of EOC overall (HR = 0.87, 95% CI: 0.69, 1.10), and serous EOC (HR = 0.71, 95% CI: 0.53, 0.96), compared with discontinued treatment, with estimates remaining constant over the 9-year follow-up. Conclusions Results from our emulated trial suggest that in women who initiated NBB treatment, those who continued use had 13% and 29% lower hazards of being diagnosed with EOC overall and serous EOC, respectively, compared with women who discontinued use.

Pre-diagnosis tea and coffee consumption and survival after a diagnosis of ovarian cancer: results from the Ovarian Cancer Association Consortium

Abstract Background Tea and coffee are the most frequently consumed beverages in the world. Green tea in particular contains compounds with potential anti-cancer effects, but its association with survival after ovarian cancer is uncertain. Methods We investigated the associations between tea and coffee consumption before diagnosis and survival using data from 10 studies in the Ovarian Cancer Association Consortium. Data on tea (green, black, herbal), coffee and caffeine intake were available for up to 5724 women. We used Cox proportional hazards regression to estimate adjusted hazard ratios (aHR) and 95% confidence intervals (CI). Results Compared with women who did not drink any green tea, consumption of one or more cups/day was associated with better overall survival (aHR = 0.84, 95% CI 0.71–1.00, p-trend = 0.04). A similar association was seen for ovarian cancer-specific survival in five studies with this information (aHR = 0.81, 0.66–0.99, p-trend = 0.045). There was no consistent variation between subgroups defined by clinical or lifestyle characteristics and adjustment for other aspects of lifestyle did not appreciably alter the estimates. We found no evidence of an association between coffee, black or herbal tea, or caffeine intake and survival. Conclusion The observed association with green tea consumption before diagnosis raises the possibility that consumption after diagnosis might improve patient outcomes.

Common analgesics and ovarian cancer survival: the Ovarian cancer Prognosis And Lifestyle (OPAL) Study

Abstract Background Most women with ovarian cancer (OC) are diagnosed with advanced disease. They often experience recurrence after primary treatment, and their subsequent prognosis is poor. Our goal was to evaluate the association between use of nonsteroidal antiinflammatory drugs (NSAIDs), including regular and low-dose aspirin, and 5-year cancer-specific survival after an OC diagnosis. Methods The Ovarian cancer Prognosis And Lifestyle study is a prospective population-based cohort of 958 Australian women with OC. Information was gathered through self-completed questionnaires. We classified NSAID use during the year prediagnosis and postdiagnosis as none or occasional (<1 d/wk), infrequent (1-3 d/wk), and frequent (≥4 d/wk) use. We measured survival from the start of primary treatment: surgery or neoadjuvant chemotherapy for analyses of prediagnosis use, or 12 months after starting treatment (postdiagnosis use) until the earliest of date of death from OC (other deaths were censored) or last follow-up to 5 years. We used Cox proportional hazards regression to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) and applied inverse-probability of treatment weighting to minimize confounding. We also calculated restricted mean survival times. Results Compared with nonusers and infrequent users, we observed better survival associated with frequent NSAID use prediagnosis (HR = 0.73, 95% CI = 0.55 to 0.97) or postdiagnosis (HR = 0.65, 95% CI = 0.45 to 0.94). Estimates were similar for aspirin and nonaspirin NSAIDs, new and continuous users and in weighted models. These differences would translate to a 2.5-month increase in mean survival by 5 years postdiagnosis. There was no association with acetaminophen. Conclusions Our findings confirm a previous study suggesting NSAID use might improve OC survival.

Folate Intake and Ovarian Cancer Risk among Women with Endometriosis: A Case–Control Study from the Ovarian Cancer Association Consortium

Abstract Background: Although folate intake has not been associated with an increased risk of ovarian cancer overall, studies of other cancer types have suggested that high folate intake may promote carcinogenesis in precancerous lesions. Women with endometriosis (a potential precancerous lesion) have an increased risk of developing ovarian cancer; however, whether high folate intake increases risk in this group is unknown. Methods: We conducted a pooled analysis of six case–control studies from the Ovarian Cancer Association Consortium to investigate the association between folate intake and risk of ovarian cancer among women with and without self-reported endometriosis. We included 570 cases/558 controls with and 5,171/7,559 without endometriosis. We used logistic regression to estimate odds ratios (OR) and 95% confidence intervals for the association between folate intake (dietary, supplemental, and total) and ovarian cancer risk. Finally, we used Mendelian randomization (MR) to evaluate our results using genetic markers as a proxy for folate status. Results: Higher dietary folate intake was associated with an increased risk of ovarian cancer for women with endometriosis [OR, 1.37 (1.01–1.86)] but not for women without endometriosis. There was no association between supplemental folate intake and ovarian cancer risk for women with or without endometriosis. A similar pattern was seen using MR. Conclusions: High dietary folate intake may be associated with an increased risk of ovarian cancer among women with endometriosis. Impact: Women with endometriosis with high folate diets may be at increased risk of ovarian cancer. Further research is needed on the potential cancer-promoting effects of folate in this group.

Statin use and survival following a diagnosis of ovarian cancer: A prospective observational study

AbstractMost women with ovarian cancer have a poor prognosis, but studies have reported an association between statin use and improved survival. We investigated the potential survival benefit of statins in women with ovarian cancer using data from the Ovarian cancer Prognosis and Lifestyle study, a prospective study of Australian women aged 18 to 79 years, diagnosed with ovarian cancer from 2012 to 2015 and followed for 5 to 8 years. We obtained information from patient‐completed questionnaires and medical records. We defined exposure based on prediagnosis use, as most women used statins continuously (prediagnosis and postdiagnosis) and few started using statins postdiagnosis. We measured survival from date of first treatment (surgery or neoadjuvant chemotherapy) until date of death or last follow‐up. We used Cox regression to calculate hazard ratios (HR) and 95% confidence intervals (CI), adjusting for potential confounders. To reduce bias due to confounding by indication, we also applied inverse probability of treatment weighting (IPTW). Of 955 eligible women, 21% reported statin use before diagnosis. Statin users had a slightly better survival (HR = 0.90, 95% CI = 0.70‐1.15) that was driven by lipophilic statin use (HR = 0.82, 95% CI = 0.61‐1.11), with no association for hydrophilic statins (HR = 1.04, 95% CI = 0.72‐1.49). The IPTW model weighted to all women with ovarian cancer also suggested a possible reduction in mortality associated with lipophilic statins (HR = 0.80, 95% CI = 0.54‐1.21). In analyses restricted to women with hyperlipidaemia, the HRs were further from the null. Our findings are consistent with previous evidence, suggesting that lipophilic statins might improve ovarian cancer survival. Further investigation, in larger cohorts, or preferably in a randomised trial, is required.

Expanding Our Understanding of Ovarian Cancer Risk: The Role of Incomplete Pregnancies

Abstract Background Parity is associated with decreased risk of invasive ovarian cancer; however, the relationship between incomplete pregnancies and invasive ovarian cancer risk is unclear. This relationship was examined using 15 case-control studies from the Ovarian Cancer Association Consortium (OCAC). Histotype-specific associations, which have not been examined previously with large sample sizes, were also evaluated. Methods A pooled analysis of 10 470 invasive epithelial ovarian cancer cases and 16 942 controls was conducted. Odds ratios (ORs) and 95% confidence intervals (CIs) for the association between incomplete pregnancies and invasive epithelial ovarian cancer were estimated using logistic regression. All models were conditioned on OCAC study, race and ethnicity, age, and education level and adjusted for number of complete pregnancies, oral contraceptive use, and history of breastfeeding. The same approach was used for histotype-specific analyses. Results Ever having an incomplete pregnancy was associated with a 16% reduction in ovarian cancer risk (OR = 0.84, 95% CI = 0.79 to 0.89). There was a trend of decreasing risk with increasing number of incomplete pregnancies (2-sided Ptrend < .001). An inverse association was observed for all major histotypes; it was strongest for clear cell ovarian cancer. Conclusions Incomplete pregnancies are associated with a reduced risk of invasive epithelial ovarian cancer. Pregnancy, including incomplete pregnancy, was associated with a greater reduction in risk of clear cell ovarian cancer, but the result was broadly consistent across histotypes. Future work should focus on understanding the mechanisms underlying this reduced risk.

Statin use and survival among women with ovarian cancer: an Australian national data-linkage study

Five-year ovarian cancer survival rates are below 50%; there is considerable interest in whether common medications like statins may improve survival. We identified women diagnosed with ovarian cancer in Australia from 2003 to 2013 through the Australian Cancer Database and linked these records to national medication and death databases. We used Cox proportional hazards regression to estimate hazard ratios (HR) and confidence intervals (CI) for associations between statins and survival. Pre-diagnosis statin use was not associated with survival overall but was associated with better survival among women with endometrioid cancers. Statin use after diagnosis was associated with better ovarian cancer-specific survival (OVS, HR = 0.87, 95%CI 0.81-0.94), but this association was largely restricted to women who started using statins after their cancer diagnosis (OVS HR = 0.68, 0.57-0.81 vs. HR = 0.94, 0.87-1.01 for continuing users). The association was strongest for endometrioid cancers (OVS HR = 0.48, 0.29-0.77). Use of statins may confer a survival benefit for women with ovarian cancer but it is impossible to rule out bias in observational studies. Particularly problematic are reverse causation where disease status affects statin use, confounding by indication and the absence of data for women with normal cholesterol levels. A randomised trial is required to provide definitive evidence.

High Prediagnosis Inflammation-Related Risk Score Associated with Decreased Ovarian Cancer Survival

Abstract Background: There is suggestive evidence that inflammation is related to ovarian cancer survival. However, more research is needed to identify inflammation-related factors that are associated with ovarian cancer survival and to determine their combined effects. Methods: This analysis used pooled data on 8,147 women with invasive epithelial ovarian cancer from the Ovarian Cancer Association Consortium. The prediagnosis inflammation-related exposures of interest included alcohol use; aspirin use; other nonsteroidal anti-inflammatory drug use; body mass index; environmental tobacco smoke exposure; history of pelvic inflammatory disease, polycystic ovarian syndrome, and endometriosis; menopausal hormone therapy use; physical inactivity; smoking status; and talc use. Using Cox proportional hazards models, the relationship between each exposure and survival was assessed in 50% of the data. A weighted inflammation-related risk score (IRRS) was developed, and its association with survival was assessed using Cox proportional hazards models in the remaining 50% of the data. Results: There was a statistically significant trend of increasing risk of death per quartile of the IRRS [HR = 1.09; 95% confidence interval (CI), 1.03–1.14]. Women in the upper quartile of the IRRS had a 31% higher death rate compared with the lowest quartile (95% CI, 1.11–1.54). Conclusions: A higher prediagnosis IRRS was associated with an increased mortality risk after an ovarian cancer diagnosis. Further investigation is warranted to evaluate whether postdiagnosis exposures are also associated with survival. Impact: Given that pre- and postdiagnosis exposures are often correlated and many are modifiable, our study results can ultimately motivate the development of behavioral recommendations to enhance survival among patients with ovarian cancer.

Identification of a Locus Near ULK1 Associated With Progression-Free Survival in Ovarian Cancer

Abstract Background: Many loci have been found to be associated with risk of epithelial ovarian cancer (EOC). However, although there is considerable variation in progression-free survival (PFS), no loci have been found to be associated with outcome at genome-wide levels of significance. Methods: We carried out a genome-wide association study (GWAS) of PFS in 2,352 women with EOC who had undergone cytoreductive surgery and standard carboplatin/paclitaxel chemotherapy. Results: We found seven SNPs at 12q24.33 associated with PFS (P < 5 × 10–8), the top SNP being rs10794418 (HR = 1.24; 95% CI, 1.15–1.34; P = 1.47 × 10–8). High expression of a nearby gene, ULK1, is associated with shorter PFS in EOC, and with poor prognosis in other cancers. SNP rs10794418 is also associated with expression of ULK1 in ovarian tumors, with the allele associated with shorter PFS being associated with higher expression, and chromatin interactions were detected between the ULK1 promoter and associated SNPs in serous and endometrioid EOC cell lines. ULK1 knockout ovarian cancer cell lines showed significantly increased sensitivity to carboplatin in vitro. Conclusions: The locus at 12q24.33 represents one of the first genome-wide significant loci for survival for any cancer. ULK1 is a plausible candidate for the target of this association. Impact: This finding provides insight into genetic markers associated with EOC outcome and potential treatment options. See related commentary by Peres and Monteiro, p. 1604

Depot-Medroxyprogesterone Acetate Use Is Associated with Decreased Risk of Ovarian Cancer: The Mounting Evidence of a Protective Role of Progestins

AbstractBackground:Combined oral contraceptive use is associated with a decreased risk of invasive epithelial ovarian cancer (ovarian cancer). There is suggestive evidence of an inverse association between progestin-only contraceptive use and ovarian cancer risk, but previous studies have been underpowered.Methods:The current study used primary data from 7,977 women with ovarian cancer and 11,820 control women in seven case–control studies from the Ovarian Cancer Association Consortium to evaluate the association between use of depot-medroxyprogesterone acetate (DMPA), an injectable progestin-only contraceptive, and ovarian cancer risk. Logistic models were fit to determine the association between ever use of DMPA and ovarian cancer risk overall and by histotype. A systematic review of the association between DMPA use and ovarian cancer risk was conducted.Results:Ever use of DMPA was associated with a 35% decreased risk of ovarian cancer overall (OR, 0.65; 95% confidence interval, 0.50–0.85). There was a statistically significant trend of decreasing risk with increasing duration of use (Ptrend < 0.001). The systematic review yielded six studies, four of which showed an inverse association and two showed increased risk.Conclusions:DMPA use appears to be associated with a decreased risk of ovarian cancer in a duration-dependent manner based on the preponderance of evidence. Further study of the mechanism through which DMPA use is associated with ovarian cancer is warranted.Impact:The results of this study are of particular interest given the rise in popularity of progestin-releasing intrauterine devices that have a substantially lower progestin dose than that in DMPA, but may have a stronger local effect.

Copy Number Variants Are Ovarian Cancer Risk Alleles at Known and Novel Risk Loci

AbstractBackgroundKnown risk alleles for epithelial ovarian cancer (EOC) account for approximately 40% of the heritability for EOC. Copy number variants (CNVs) have not been investigated as EOC risk alleles in a large population cohort.MethodsSingle nucleotide polymorphism array data from 13 071 EOC cases and 17 306 controls of White European ancestry were used to identify CNVs associated with EOC risk using a rare admixture maximum likelihood test for gene burden and a by-probe ratio test. We performed enrichment analysis of CNVs at known EOC risk loci and functional biofeatures in ovarian cancer–related cell types.ResultsWe identified statistically significant risk associations with CNVs at known EOC risk genes; BRCA1 (PEOC = 1.60E-21; OREOC = 8.24), RAD51C (Phigh-grade serous ovarian cancer [HGSOC] = 5.5E-4; odds ratio [OR]HGSOC = 5.74 del), and BRCA2 (PHGSOC = 7.0E-4; ORHGSOC = 3.31 deletion). Four suggestive associations (P < .001) were identified for rare CNVs. Risk-associated CNVs were enriched (P < .05) at known EOC risk loci identified by genome-wide association study. Noncoding CNVs were enriched in active promoters and insulators in EOC-related cell types.ConclusionsCNVs in BRCA1 have been previously reported in smaller studies, but their observed frequency in this large population-based cohort, along with the CNVs observed at BRCA2 and RAD51C gene loci in EOC cases, suggests that these CNVs are potentially pathogenic and may contribute to the spectrum of disease-causing mutations in these genes. CNVs are likely to occur in a wider set of susceptibility regions, with potential implications for clinical genetic testing and disease prevention.

Modification of the Association Between Frequent Aspirin Use and Ovarian Cancer Risk: A Meta-Analysis Using Individual-Level Data From Two Ovarian Cancer Consortia

PURPOSE Frequent aspirin use has been associated with reduced ovarian cancer risk, but no study has comprehensively assessed for effect modification. We leveraged harmonized, individual-level data from 17 studies to examine the association between frequent aspirin use and ovarian cancer risk, overall and across subgroups of women with other ovarian cancer risk factors. METHODS Nine cohort studies from the Ovarian Cancer Cohort Consortium (n = 2,600 cases) and eight case-control studies from the Ovarian Cancer Association Consortium (n = 5,726 cases) were included. We used Cox regression and logistic regression to assess study-specific associations between frequent aspirin use (≥ 6 days/week) and ovarian cancer risk and combined study-specific estimates using random-effects meta-analysis. We conducted analyses within subgroups defined by individual ovarian cancer risk factors (endometriosis, obesity, family history of breast/ovarian cancer, nulliparity, oral contraceptive use, and tubal ligation) and by number of risk factors (0, 1, and ≥ 2). RESULTS Overall, frequent aspirin use was associated with a 13% reduction in ovarian cancer risk (95% CI, 6 to 20), with no significant heterogeneity by study design ( P = .48) or histotype ( P = .60). Although no association was observed among women with endometriosis, consistent risk reductions were observed among all other subgroups defined by ovarian cancer risk factors (relative risks ranging from 0.79 to 0.93, all P-heterogeneity > .05), including women with ≥ 2 risk factors (relative risk, 0.81; 95% CI, 0.73 to 0.90). CONCLUSION This study, the largest to-date on aspirin use and ovarian cancer, provides evidence that frequent aspirin use is associated with lower ovarian cancer risk regardless of the presence of most other ovarian cancer risk factors. Risk reductions were also observed among women with multiple risk factors, providing proof of principle that chemoprevention programs with frequent aspirin use could target higher-risk subgroups.

Dietary Practices After Primary Treatment for Ovarian Cancer: A Qualitative Analysis From the OPAL Study

Little is known about the dietary practices of women who have completed primary treatment for ovarian cancer, many of whom will go on to have cancer recurrence and further treatment. Knowledge of dietary practices is needed to optimize care. Our aim was to identify dietary practices after primary treatment for ovarian cancer and evaluate how these practices differ by disease recurrence and treatment status. Women with invasive epithelial ovarian cancer were provided with the following open-ended question after completing a food frequency questionnaire: "Is there anything we haven't asked you about your diet in the last 1 to 2 months that you feel is important?" Participants were from the OPAL (Ovarian Cancer Prognosis and Lifestyle) Study in Australia. The main outcomes were dietary practices after primary treatment for ovarian cancer and factors affecting these practices. Participants' responses were analyzed using content analysis. Individual content codes were categorized and reported by recurrence and treatment status at questionnaire completion. Two hundred eighty-six women provided responses on 363 questionnaires. Those undergoing further treatment for recurrence commonly reported dietary regimens with clinical indications (eg, low fiber to avoid bowel obstructions, high energy/protein to minimize nutritional deficits). Those not undergoing further treatment frequently reported "popular" diets (eg, organic, plant-based, and alkaline). For women with cancer recurrence, dietary practices were affected by poor appetite and late effects of treatment. For women without recurrence, other comorbidities, geographical location, family, and friends appeared to influence dietary practices. In both groups, nutrition information sources and personal beliefs informed dietary practices. Participant responses that referenced media or online sources often included misinformation. After primary treatment for ovarian cancer, women report dietary practices that may not be captured in standard food frequency questionnaires. Dietary practices and factors affecting these practices likely differ by treatment and recurrence status. Improved access to evidence-based dietary information and support is needed.

Nitrogen-based Bisphosphonate Use and Ovarian Cancer Risk in Women Aged 50 Years and Older

Abstract Background There are few readily modifiable risk factors for epithelial ovarian cancer; preclinical studies suggest bisphosphonates could have chemopreventive actions. Our study aimed to assess the association between use of nitrogen-based bisphosphonate medicine and risk of epithelial ovarian cancer, overall and by histotype. Methods We conducted a case-control study nested within a large, linked administrative dataset including all Australian women enrolled for Medicare, Australia’s universal health insurance scheme, between July 2002 and December 2013. We included all women with epithelial ovarian cancer diagnosed at age 50 years and older between July 1, 2004, and December 31, 2013 (n = 9367) and randomly selected up to 5 controls per case, individually matched to cases by age, state of residence, area-level socioeconomic status, and remoteness of residence category (n = 46 830). We used prescription records to ascertain use of nitrogen-based bisphosphonates (ever use and duration of use), raloxifene, and other osteoporosis medicines (no nitrogen-based bisphosphonates, strontium and denosumab). We calculated adjusted odds ratios (OR) and 95% confidence intervals (CI) using conditional logistic regression. Results Ever use of nitrogen-based bisphosphonates was associated with a reduced risk of epithelial ovarian cancer compared with no use (OR = 0.81, 95% CI = 0.75 to 0.88). There was a reduced risk of endometrioid (OR = 0.51, 95% CI = 0.33 to 0.79) and serous histotypes (OR = 0.84, 95% CI = 0.75 to 0.93) but no association with the mucinous or clear cell histotypes. Conclusion Use of nitrogen-based bisphosphonates was associated with a reduced risk of endometrioid and serous ovarian cancer. This suggests the potential for use for prevention, although validation of our findings is required.

Exploring estrogen-related mechanisms in ovarian carcinogenesis: association between bone mineral density and ovarian cancer risk in a multivariable Mendelian randomization study

Abstract Background Estrogen may play a role in epithelial ovarian cancer (EOC) carcinogenesis, with effects varying by EOC histotype. Measuring women’s long-term exposure to estrogen is difficult, but bone mineral density (BMD) may be a reasonable proxy of longer-term exposure. We examined this relationship by assessing the association between genetic predisposition for higher BMD and risk of EOC by histotype. Methods We used Mendelian randomization (MR) to assess associations between genetic markers for femoral neck and lumbar spine BMD and each EOC histotype. We used multivariable MR (MVMR) to adjust for probable pleiotropic traits, including body mass index, height, menarcheal age, menopausal age, smoking, alcohol intake, and vitamin D. Results Univariable analyses suggested greater BMD was associated with increased risk of endometrioid EOC (per standard deviation increase; lumbar spine OR = 1.21; 95% CI 0.93,1.57, femoral neck: OR = 1.25; 0.99,1.57), but sensitivity analyses indicated that pleiotropy was likely. Adjustment using MVMR reduced the magnitude of estimates slightly (lumbar spine: OR = 1.13; 95% CI 1.00,1.28, femoral neck: OR = 1.18; 1.03,1.36). Results for lumbar spine BMD and high-grade serous EOC were also suggestive of an association (univariable MR: OR = 1.16; 95% CI 1.03,1.30; MVMR: OR = 1.06; 0.99,1.14). Conclusion Our study found associations between genetic predisposition to higher BMD, a proxy for long-term estrogen exposure, and risk of developing endometroid and high-grade serous EOC cancers. These findings add to existing evidence of the relationship between estrogen and increased risk of EOC for certain histotypes.

Angiotensin converting enzyme inhibitors and angiotensin receptor blockers and ovarian cancer survival: the Ovarian cancer Prognosis And Lifestyle (OPAL) study

There is some evidence that angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB) might improve cancer survival, but reliable data for ovarian cancer are scarce. We evaluated this using data from the prospective Ovarian cancer Prognosis and Lifestyle (OPAL) study. We included 954 Australian women diagnosed between 2012 and 2015 and considered pre-diagnosis and post-diagnosis medication use and ovarian cancer survival. We used Cox proportional hazard models to estimate adjusted hazard ratios (aHR) and 95 % confidence intervals (CI) for all medication users and monotherapy users (those who used a single medication). We applied inverse probability of treatment weighting to further reduce confounding and estimated restricted mean survival time at 7 years (end of study). We observed a modest association between ARB use before or after diagnosis and progression-free and ovarian cancer-specific survival. Estimates were further from the null for post-diagnosis use ARB monotherapy, and when weighted for users (pre-diagnosis use aHR=0.71, 95 %CI: 0.51-0.98; post-diagnosis use aHR=0.60, 0.36-1.01 for ovarian cancer-specific survival). If real, this would translate to a 6-month increase in mean survival for ARB monotherapy. The associations were attenuated in models weighted for all women. There was little evidence of an association with ACE inhibitors. Further evaluation in larger cohorts is required to confirm these findings. If the observed associations are confirmed, ARBs may warrant consideration as a first line hypertension treatment for women with ovarian cancer.

Hypertension and Risk of Endometrial Cancer: A Pooled Analysis in the Epidemiology of Endometrial Cancer Consortium (E2C2)

Abstract Background: The incidence rates of endometrial cancer are increasing, which may partly be explained by the rising prevalence of obesity, an established risk factor for endometrial cancer. Hypertension, another component of metabolic syndrome, is also increasing in prevalence, and emerging evidence suggests that it may be associated with the development of certain cancers. The role of hypertension independent of other components of metabolic syndrome in the etiology of endometrial cancer remains unclear. In this study, we evaluated hypertension as an independent risk factor for endometrial cancer and whether this association is modified by other established risk factors. Methods: We included 15,631 endometrial cancer cases and 42,239 controls matched on age, race, and study-specific factors from 29 studies in the Epidemiology of Endometrial Cancer Consortium. We used multivariable unconditional logistic regression models to estimate ORs and 95% confidence intervals (CI) to evaluate the association between hypertension and endometrial cancer and whether this association differed by study design, race/ethnicity, body mass index, diabetes status, smoking status, or reproductive factors. Results: Hypertension was associated with an increased risk of endometrial cancer (OR, 1.14; 95% CI, 1.09–1.19). There was significant heterogeneity by study design (Phet < 0.01), with a stronger magnitude of association observed among case–control versus cohort studies. Stronger associations were also noted for pre-/perimenopausal women and never users of postmenopausal hormone therapy. Conclusions: Hypertension is associated with endometrial cancer risk independently from known risk factors. Future research should focus on biologic mechanisms underlying this association. Impact: This study provides evidence that hypertension may be an independent risk factor for endometrial cancer.

432Works
31Papers
182Collaborators
Ovarian NeoplasmsEndometrial NeoplasmsPrognosisGenital Neoplasms, FemaleBreast NeoplasmsNeoplasms

Positions

2000–

Group Leader

QIMR Berghofer Medical Research Institute · Population Health

Education

1994

DPhil

University of Oxford

1986

BA

University of Cambridge

Keywords
Cancer epidemiologyGynaecological cancer
Links & IDs
0000-0003-0733-5930Google Scholar

Scopus: 57218216323

Researcher Id: D-5736-2013