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.

Mixed endometrial carcinoma (MEEC) refers to rare endometrial tumours that are composed of two or more distinct histotypes, at least one of which is serous or clear cell. The aim of this study was to evaluate the epidemiology, treatment outcomes and survival rates of patients with mixed endometrial carcinoma. The medical records of 34 patients diagnosed with MEEC between March 2010 and January 2020 were reviewed retrospectively. Clinicopathological variables and treatment strategies were assessed, and overall survival and disease-free survival rates were evaluated. The histology of endometrioid and serous component was found in 26 (76.5%) patients, followed by serous and clear-cell components (5/34, 14.5%) and mixed endometrioid serous and clear-cell components (3/34, 8.8%). The median age at diagnosis was 70 years (range 52-84), and the median follow-up time was 55 months. The 5-year disease-free survival and the 5-year overall survival were 50.4% and 52.4%, respectively. Advanced disease stage was identified as an independent predictor of inferior disease-free (<0.003) and overall survival (p < 0.001). Except for stage, none of the traditional prognostic factors was associated with disease recurrence or death from disease. MEECs represent rare high-risk endometrial carcinomas with significant diagnostic and treatment challenges. Undoubtedly, the implementation of a molecular analysis can offer further diagnostic and management insights.

Endometrial cancers have high rates of phosphoinositide 3-kinase (PI3K) pathway alterations. MK-2206 is an allosteric inhibitor of AKT, an effector kinase of PI3K signals. We hypothesized patients with tumors harboring PIK3CA mutations would be more likely to benefit from MK-2206 than those without PIK3CA mutation. A Phase II study was performed in patients with recurrent endometrial cancer; all histologies except carcinosarcoma were eligible. Up to two prior chemotherapy lines were permitted, excluding prior treatment with PI3K pathway inhibitors. The first 18 patients were treated with MK-2206 200 mg weekly. Due to unacceptable toxicity, dose was reduced to 135 mg. Co-primary endpoints were objective response rate (ORR) and progression-free survival at 6 months (6moPFS). Thirty-seven patients were enrolled (one ineligible). By somatic PIK3CA mutation analysis, nine patients were mutant (MT) [one with partial response (PR)/6moPFS, two with 6moPFS]. Twenty-seven patients were wild-type (WT) (one PR and four 6moPFS). Most common toxicities were rash (44%), fatigue (41%), nausea (42%) and hyperglycemia (31%). Grade 3 and 4 toxicities occurred in 25 and 17% of patients, respectively. Exploratory analysis found serous histology had greater 6moPFS as compared to all other histologies (5/8 vs. 2/28, p = 0.003). PTEN expression was associated with median time to progression (p = 0.04). No other significant associations with PI3K pathway alterations were identified. There is limited single agent activity of MK-2206 in PIK3CA MT and PIK3CA WT endometrial cancer populations. Activity was detected in patients with serous histology and due to their poor outcomes warrants further study (NCT01307631).

Although obesity has been associated with endometrioid (type I) and, to a lesser extent, with serous (type II) endometrial cancer (EC), the association with the same histotypes of ovarian cancer (OC) remains unclear. Therefore, we intended to compare the role of BMI in carcinogenesis of endometrioid and the serous malignancies, at both ovarian and endometrial level.
A retrospective case-to-case study was performed in the University Hospital of Bologna (Italy), through the review of primary EC matched with the corresponding OC cases in the same period (1988-2017).
We included 1052 women diagnosed with EC (n = 897 endometrioid, n = 52 serous) and 955 women affected by OC (n = 132 endometrioid, n = 627 serous). EC patients had higher median BMI than women diagnosed with OC (27.3 [23.4-31.9] vs 24.9 [21.7-27.5], p < 0.01). After controlling for confounding, 1 unit increase in BMI was associated with a 5% higher odds of endometrial as opposed to ovarian cancer (OR for ovarian as opposed to endometrial cancer 0.95; 95% CI 0.91-0.98, p = 0.004).
Increasing BMI is associated with endometrial rather than ovarian cancer, among both serous and endometrioid histotypes.

BACKGROUND: Prior small studies have shown increased expression of sperm protein 17 (Sp17) in epithelial ovarian cancer (EOC) tissue and suggest Sp17 as a potential biomarker for EOC. However, how Sp17 expression varies with histology, grade, and stage of EOC and its expression in other ovarian neoplasms has not been defined. It is unknown whether patients with EOC have elevated serum Sp17 levels or if Sp17 expression is associated with survival outcomes.
METHODS: The study included 982 patients with benign, borderline, and malignant ovarian neoplasms and normal ovary. There were 878 patients with tissue only, 39 with serum only, and 65 with matching serum and tissue. Immunohistochemical (IHC) staining with anti-Sp17 antibody was performed on tissue specimens and the intensity scored as weak, moderate, or strong. A sandwich enzyme-linked immunosorbent assay (ELISA) was performed to measure Sp17 sera concentrations.
RESULTS: Sp17 expression was most commonly seen in serous cystadenomas (83%) and serous borderline tumors (100%). Of the 773 EOC specimens, 223 (30%) expressed Sp17. Grade and histology were significantly associated with Sp17 expression among EOC specimens (p < 0.001) on both univariate and multivariable analysis, with grade 1 serous adenocarcinomas showing the highest expression (51%). Sp17 expression was limited in other benign and non-epithelial malignant neoplasms. Neither Sp17 tissue expression nor serum concentration correlated with survival outcomes. Serum concentrations were higher in patients with Sp17 tissue expression, and the highest concentrations were noted among patients with serous and clear cell adenocarcinomas.
CONCLUSIONS: Sp17 is highly expressed in benign, borderline, and low grade malignant serous ovarian neoplasms and can be quantified in serum. Sp17 expression may have diagnostic significance in this subset of patients.

OBJECTIVE: To assess the association of hormone receptor expression with outcome in high-grade endometrial carcinomas.
METHODS: This study included three sites participating in the Canadian High Risk Endometrial Cancer (CHREC) consortium. Sections from tissue microarrays containing cases with a diagnosis of endometrioid grade 3 (EC3) and endometrial serous carcinoma (ESC) were assessed for estrogen (ER) and progesterone receptor (PR) expression by immunohistochemistry. Expression was considered present if >1% of tumor cell nuclei were labeled. Associations with overall survival were assessed.
RESULTS: ER expression was present in 168/216 (78%) of EC3 and 124/192 (65%) of ESC. PR expression was present in 148/212 (70%) of EC3 and 83/196 (42%) of ESC. PR expression was significantly associated with favorable overall survival in EC3 and ESC (log rank, p=0.018 and p=0.0024) but ER expression was not. PR expression was significantly associated with favorable overall survival in EC3 independent of age, stage, center and lymph-vascular invasion (hazard ratio=0.457, 95% CI 0.257-0.811, p=0.0075) as well as in stage I and II ESC (hazard ratio=0.266, 95% CI 0.094-0.750, p=0.0123).
CONCLUSIONS: Our data provide support for the assessment of the PR expression status in EC3 and ESC. Future work will be required to determine how PR expression may be incorporated into management of patients with EC3 and ESC.

BACKGROUND: Studies of the role of dietary factors in epithelial ovarian cancer (EOC) development have been limited, and no specific dietary factors have been consistently associated with EOC risk.
OBJECTIVE: We used a nutrient-wide association study approach to systematically test the association between dietary factors and invasive EOC risk while accounting for multiple hypothesis testing by using the false discovery rate and evaluated the findings in an independent cohort.
METHODS: We assessed dietary intake amounts of 28 foods/food groups and 29 nutrients estimated by using dietary questionnaires in the EPIC (European Prospective Investigation into Cancer and Nutrition) study (n = 1095 cases). We selected 4 foods/nutrients that were statistically significantly associated with EOC risk when comparing the extreme quartiles of intake in the EPIC study (false discovery rate = 0.43) and evaluated these factors in the NLCS (Netherlands Cohort Study; n = 383 cases). Cox regression models were used to estimate HRs and 95% CIs.
RESULTS: None of the 4 dietary factors that were associated with EOC risk in the EPIC study (cholesterol, polyunsaturated and saturated fat, and bananas) were statistically significantly associated with EOC risk in the NLCS; however, in meta-analysis of the EPIC study and the NLCS, we observed a higher risk of EOC with a high than with a low intake of saturated fat (quartile 4 compared with quartile 1; overall HR: 1.21; 95% CI: 1.04, 1.41).
CONCLUSIONS: In the meta-analysis of both studies, there was a higher risk of EOC with a high than with a low intake of saturated fat.

OBJECTIVE: Invasive serous adenocarcinomas may present as primary ovarian (POC), primary fallopian tube (PFC) or primary peritoneal (PPC) carcinomas. Whether they are variants of the same malignancy or develop through different pathways is debated.
METHODS: Population-based prospectively collected data on POC (n=1443), PPC (n=268) and PFC (n=171) cases was obtained from the Danish Gynecological Cancer Database (2005-2013). Chi-square, Fisher\'s or Wilcoxon-Mann-Whitney test, multivariate logistic regression, Kaplan-Meier and multivariate Cox-regression were used as appropriate. Statistical tests were 2-sided. P-values of <0.05 were considered statistically significant.
RESULTS: PPC cases were older (P<0.0001), had a later age at menarche (P=0.02), a higher percentage were multi-parous (≥two children vs. no children) OR 1.70 (1.01-2.49) and both PPC and PFC tended to have a higher BMI (>35 vs. >18.5-25) than POC cases. PFC cases were diagnosed in earlier stages (P<0.001). In advanced stages a lower proportion had preoperative carcinosis or ascites, and a higher percentage had macro-radical surgery or lymphadenectomy compared to POC. In contrast, more PPC cases had post-operative carcinosis; whereas a lower proportion had lymphadenectomy or macro-radical surgery compared to POC. PPC had a significantly lower overall survival than POC, HR=1.24 (1.04-1.47).
CONCLUSIONS: We found differences in risk pattern profiles among the three groups, especially for PPC. Furthermore, the severity of stage specific disease differed significantly according to location, resulting in a lower overall survival for PPC. These differences warrant further research to determine to what extent PPC is a distinct disease entity.