Christine M Friedenreich

Risk factors for second primary cancer in a prospective cohort of endometrial cancer survivors: an Alberta Endometrial Cancer Cohort Study

Abstract We examined associations between modifiable and nonmodifiable cancer-related risk factors measured at endometrial cancer diagnosis and during early survivorship (~3 years postdiagnosis) with second primary cancer (SPC) risk among 533 endometrial cancer survivors in the Alberta Endometrial Cancer Cohort using Fine and Gray subdistribution hazard models. During a median follow-up of 16.7 years (IQR, 12.2-17.9), 89 (17%) participants developed an SPC; breast (29%), colorectal (13%), and lung (12%) cancers were the most common. Dietary glycemic load before endometrial cancer diagnosis (≥90.4 vs < 90.4 g/day: subhazard ratio [sHR] = 1.71; 95% CI, 1.09-2.69), as well as older age (≥60 vs < 60 years: sHR = 2.48; 95% CI, 1.34-4.62) and alcohol intake (≥2 drinks/week vs none: sHR = 3.81; 95% CI, 1.55-9.31) during early survivorship, were associated with increased SPC risk. Additionally, reductions in alcohol consumption from prediagnosis to early survivorship significantly reduced SPC risk (sHR = 0.34; 95% CI, 0.14-0.82). With 1 in 6 survivors developing an SPC, further investigation of SPC risk factors and targeted surveillance options for high-risk survivors could improve long-term health outcomes in this population. Reductions in dietary glycemic load and alcohol intake from prediagnosis to early survivorship showed promising risk reductions for SPCs and could be important modifiable risk factors to target among endometrial cancer survivors. This article is part of a Special Collection on Gynecological Cancer.

Prospective Cohort of Pre- and Post-Diagnosis Diet with Survival Outcomes: an Alberta Endometrial Cancer Cohort Study

Abstract Background: The prognostic relationship between diet and endometrial cancer survival remains largely unknown. We sought to determine pre- and post-diagnosis dietary composition, glycemic load (GL), inflammatory potential (dietary inflammatory index) and quality [Canadian Healthy Eating Index (C-HEI) 2005] associations with disease-free (DFS) and overall survival (OS) among endometrial cancer survivors. In addition, we assessed associations between dietary changes with OS and explored obesity/physical activity effect modification. Methods: Survivors, diagnosed in Alberta, Canada between 2002 and 2006, completed past-year, food-frequency questionnaires at-diagnosis (n = 503) and 3-year follow-up (n = 395). Participants were followed to death or January 2022. Cox proportional regression estimated HR [95% confidence intervals (CI)] for dietary survival associations. Results: During 16.9 median years of follow-up, 138 participants had a DFS event and 120 died. Lower pre-diagnosis GL (HRT1vsT3, 0.49; 95% CI, 0.25–0.97) and greater post-diagnosis energy intakes (EI) from total- and monounsaturated-fat (HRT3vsT1, 0.48; 95% CI, 0.26–0.87) were associated with better OS. Higher pre-diagnosis C-HEI, less inflammatory diets and lower added sugar intakes were nonlinearly associated with better DFS. Consistently low pre- to post-diagnosis EI from carbohydrates and total-fats were associated with better (HR, 0.36; 95% CI, 0.18–0.72) and worse (HR, 2.26; 95% CI, 1.21–4.20) OS, respectively. Decreased pre- to post-diagnosis C-HEI was associated with worse OS. In stratified analysis, healthy diets were most beneficial for survivors with obesity and physical inactivity. Conclusions: Adherence to higher quality dietary patterns were associated with better survival. Impact: Our study provides novel evidence that both pre- and post-diagnosis diet are important prognostic factors for endometrial cancer survivors. Post-diagnosis survival associations with diet composition and quality highlight the potential for future interventions.

Prospective Cohort Study of Pre- and Postdiagnosis Obesity and Endometrial Cancer Survival

AbstractBackgroundDisease-free survival (DFS) and overall survival (OS) associations with anthropometric measures of obesity and changes in these exposures remain unknown among endometrial cancer survivors.MethodsEndometrial cancer survivors diagnosed between 2002 and 2006 completed direct anthropometric measurements and self-reported lifetime weight history during in-person interviews approximately 4 months after diagnosis (peridiagnosis) and approximately 3 years after diagnosis (follow-up). Participants were followed-up until death or March 20, 2019. Cox proportional regression was used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for body mass index (BMI), weight, waist circumference, and waist-hip ratio with DFS and OS. Statistical tests were 2-sided.ResultsA total of 540 and 425 cancer survivors were assessed peridiagnosis and follow-up, respectively. During the median 14.2 years of follow-up (range = 0.3-16.5 years), 132 participants had a recurrence and/or died (DFS), with 111 deaths overall (OS). Reduced DFS was noted with greater recalled weight 1 year before diagnosis (HR = 1.88, 95% CI = 1.15 to 3.07), BMI 1 year before diagnosis (HR = 1.88, 95% CI = 1.09 to 3.22), and measured peridiagnosis BMI (HR = 2.04, 95% CI = 1.18 to 3.53). Measured peridiagnosis waist circumference of at least 88 cm was associated with decreased DFS (HR = 1.94, 95% CI = 1.24 to 3.03) and OS (HR = 1.90, 95% CI = 1.16 to 3.13). A twofold decrease in DFS and OS was associated with a BMI of at least 5% or weight change from 1 year before diagnosis to peridiagnosis. No associations were observed for the assessment during follow-up.ConclusionsOne-year before- and peridiagnosis anthropometric measures of obesity were associated with reduced survival among endometrial cancer survivors. Anthropometric changes from 1 year before to peridiagnosis may provide an important indication of future survival in this population.

Obesity and mortality among endometrial cancer survivors: A systematic review and meta‐analysis

SummaryExcess body fat is a major risk factor for endometrial cancer incidence, but its impact on recurrence and survival remains unclear. The aim of this systematic review and meta‐analysis was to assess the association between excess body fat with recurrence, cancer‐specific, and all‐cause mortality among endometrial cancer survivors. We searched MEDLINE and EMBASE databases up to July 2021. Risk of bias was assessed with the Ottawa Newcastle Scale. Random effects models estimated pooled hazard ratios for the main associations between body mass index (BMI) and survival outcomes and stratified by endometrial cancer type. Potential heterogeneity and publication bias were evaluated with sensitivity analyses, funnel plots, and Egger's test. Forty‐six studies were included, of which 45 estimated body fat with BMI and six used direct waist circumference measures or CT/MRI scans. Higher BMI (≥30 kg/m2) was associated with increased all‐cause mortality (HR = 1.34, 95%CI = 1.12–1.59) and recurrence (HR = 1.28, 95%CI = 1.06–1.56). In sub‐group analysis, associations between higher BMI and all‐cause mortality were observed for both Types I and II survivors, while recurrence associations were only significant among Type I cases. Obesity at endometrial cancer diagnosis was associated with increased cancer recurrence and all‐cause mortality among endometrial cancer survivors but not endometrial cancer‐specific mortality.

Prospective Cohort Study of Pre- and Postdiagnosis Physical Activity and Endometrial Cancer Survival

PURPOSE The aim of this study was to evaluate associations between pre- and postdiagnosis physical activity and survival in survivors of endometrial cancer by physical activity domain, intensity, dose (metabolic-equivalent task [MET]-hours/week/year), and change from pre- to postdiagnosis. METHODS We conducted a prospective cohort study in Alberta, Canada, of 425 women who were diagnosed with histologically confirmed invasive endometrial cancer between 2002 and 2006 and observed to 2019. The interviewer-administered Lifetime Total Physical Activity Questionnaire recorded prediagnosis (assessed at a median of 4.4 months after diagnosis) and postdiagnosis physical activity (assessed at a median of 3.4 years after diagnosis). Associations between physical activity and overall and disease-free survival were assessed using Cox proportional hazards models adjusted for age, stage, grade, treatments, body mass index, menopausal status, hormone therapy use, family history of cancer, and comorbidities. RESULTS After a median follow-up of 14.5 years, there were 60 deaths, including 18 endometrial cancer deaths, and 80 disease-free survival events. Higher prediagnosis recreational physical activity was statistically significantly associated with improved disease-free survival (> 14 v ≤ 8 MET-hours/week/year; hazard ratio [HR], 0.54; 95% CI, 0.30 to 0.96; Ptrend = .04), but not overall survival (HR, 0.56; 95% CI, 0.29 to 1.07; Ptrend = .06). Higher postdiagnosis recreational physical activity (> 13 v ≤ 5 MET-hours/week/year) was strongly associated with both improved disease-free survival (HR, 0.33; 95% CI, 0.17 to 0.64; Ptrend = .001) and overall survival (HR, 0.33; 95% CI, 0.15 to 0.75; Ptrend = .007). Participants who maintained high recreational physical activity levels from pre- to postdiagnosis also had improved disease-free survival (HR, 0.35; 95% CI, 0.18 to 0.69) and overall survival (HR, 0.43; 95% CI, 0.20 to 0.94) compared with those who maintained low physical activity levels. CONCLUSION Recreational physical activity, especially postdiagnosis, is associated with improved survival in survivors of endometrial cancer.

Mendelian randomization analyses suggest a role for cholesterol in the development of endometrial cancer

AbstractBlood lipids have been associated with the development of a range of cancers, including breast, lung and colorectal cancer. For endometrial cancer, observational studies have reported inconsistent associations between blood lipids and cancer risk. To reduce biases from unmeasured confounding, we performed a bidirectional, two‐sample Mendelian randomization analysis to investigate the relationship between levels of three blood lipids (low‐density lipoprotein [LDL] and high‐density lipoprotein [HDL] cholesterol, and triglycerides) and endometrial cancer risk. Genetic variants associated with each of these blood lipid levels (P < 5 × 10−8) were identified as instrumental variables, and assessed using genome‐wide association study data from the Endometrial Cancer Association Consortium (12 906 cases and 108 979 controls) and the Global Lipids Genetic Consortium (n = 188 578). Mendelian randomization analyses found genetically raised LDL cholesterol levels to be associated with lower risks of endometrial cancer of all histologies combined, and of endometrioid and non‐endometrioid subtypes. Conversely, higher genetically predicted HDL cholesterol levels were associated with increased risk of non‐endometrioid endometrial cancer. After accounting for the potential confounding role of obesity (as measured by genetic variants associated with body mass index), the association between genetically predicted increased LDL cholesterol levels and lower endometrial cancer risk remained significant, especially for non‐endometrioid endometrial cancer. There was no evidence to support a role for triglycerides in endometrial cancer development. Our study supports a role for LDL and HDL cholesterol in the development of non‐endometrioid endometrial cancer. Further studies are required to understand the mechanisms underlying these findings.

Case–control study of endogenous sex steroid hormones and risk of endometrial cancer

Epidemiologic evidence regarding the role of endogenous sex hormones in endometrial cancer etiology remains inconsistent. The objective of this study was to investigate if circulating levels of endogenous estrone, estradiol, sex hormone binding globulin (SHBG), testosterone, and androstenedione are associated with endometrial cancer risk. We conducted a population-based case-control study of 522 incident endometrial cancer cases and 976 population controls, in Alberta, Canada from 2002 to 2006. Study participants completed in-person interviews and provided fasting blood samples. Sex hormone levels were determined by enzyme-linked immunosorbent assays. Higher levels of androstenedione were associated with increased endometrial cancer risk (OR 1.44, 95% CI 1.04-2.02). Endometrial cancer risk in pre- and peri-menopausal women was reduced for the highest versus lowest quartiles of estrone (OR 0.44, 95% CI 0.22-0.88) and estradiol (OR 0.30, 95% CI 0.14-0.65), but in post-menopausal women, the endometrial cancer risk was increased for the highest versus lowest quartile of androstenedione (OR 1.82, 95% CI 1.25-2.65). In addition, endometrial cancer risk in normal/underweight women was decreased for the highest versus lowest quartile of serum SHBG (OR 0.39, 95% CI 0.19-0.84). Overall, positive associations were found for androstenedione concentrations, while sub-group analyses revealed = inverse associations with estrogens and SHBG. Results of this study provide empirical evidence for the role of circulating sex hormones in endometrial cancer etiology and highlight the importance of modifiable factors that contribute to changes in sex hormone concentration levels.

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.