Anne M van Altena

Lifetime ovulatory years and risk of epithelial ovarian cancer: a multinational pooled analysis

Abstract Background The role of ovulation in epithelial ovarian cancer (EOC) is supported by the consistent protective effects of parity and oral contraceptive use. Whether these factors protect through anovulation alone remains unclear. We explored the association between lifetime ovulatory years (LOY) and EOC. Methods LOY was calculated using 12 algorithms. Odds ratios (ORs) and 95% confidence intervals (CIs) estimated the association between LOY or LOY components and EOC among 26 204 control participants and 21 267 case patients from 25 studies. To assess whether LOY components act through ovulation suppression alone, we compared beta coefficients obtained from regression models with expected estimates assuming 1 year of ovulation suppression has the same effect regardless of source. Results LOY was associated with increased EOC risk (OR per year increase = 1.014, 95% CI = 1.009 to 1.020 to OR per year increase = 1.044, 95% CI = 1.041 to 1.048). Individual LOY components, except age at menarche, also associated with EOC. The estimated model coefficient for oral contraceptive use and pregnancies were 4.45 times and 12- to 15-fold greater than expected, respectively. LOY was associated with high-grade serous, low-grade serous, endometrioid, and clear cell histotypes (ORs per year increase = 1.054, 1.040, 1.065, and 1.098, respectively) but not mucinous tumors. Estimated coefficients of LOY components were close to expected estimates for high-grade serous but larger than expected for low-grade serous, endometrioid, and clear cell histotypes. Conclusions LOY is positively associated with nonmucinous EOC. Differences between estimated and expected model coefficients for LOY components suggest factors beyond ovulation underlie the associations between LOY components and EOC in general and for non-HGSOC.

Incidence and predictors of peritoneal metastases of gynecological origin: a population-based study in the Netherlands

Peritoneal metastases (PM) are a challenge in gynecological cancers, but its appearance has never been described in a population-based study. Therefore, we describe the incidence of PM and identify predictors that increase the probability of peritoneal spread. All ovarian, endometrial and cervical cancer patients diagnosed in the Netherlands between 1989 and 2015 were identified from the Netherlands Cancer Registry and stratified for PM. Crude and age-adjusted incidence over time was calculated. Independent predictors for PM were identified using uni- and multivariable analyses. The 94,981 patients were diagnosed with ovarian, endometrial or cervical cancer and respectively 61%, 2% and 1% presented with PM. Predictors for PM in ovarian cancer were: age between 50 and 74 years (odds ratio [OR]=1.19; 95% confidence interval [CI]=1.08-1.32), other distant metastases (OR=1.25; 95% CI=1.10-1.41), poor differentiation grade (OR=2.00; 95% CI=1.73-2.32) and serous histology. Predictors in endometrial cancer were lymph node metastases (OR=2.32; 95% CI=1.65-3.26), other distant metastases (OR=1.38; 95% CI=1.08-1.77), high-grade tumors (OR=1.95; 95% CI=1.38-2.76) and clear cell (OR=1.49; 95% CI=1.04-2.13) or serous histology (OR=2.71; 95% CI=2.15-3.42). In cervical cancer, the risk is higher in adenocarcinoma than in squamous cell carcinoma (OR=4.92; 95% CI=3.11-7.79). PM are frequently seen in patients with ovarian cancer. In endometrial and cervical cancer PM are rare. Histological subtype was the strongest predictive factor for PM in all 3 cancers. Better understanding of predictive factors for PM and thus the biological behavior is of paramount importance.