Genome-wide association study of subtype-specific epithelial ovarian cancer risk alleles using pooled DNA.

Epithelial ovarian cancer (EOC) is a heterogeneous cancer with both genetic and environmental risk factors. Variants influencing the risk of developing the less-common EOC subtypes have not been fully investigated. We performed a genome-wide association study (GWAS) of EOC according to subtype by pooling genomic DNA from 545 cases and 398 controls of European descent, and testing for allelic associations. We evaluated for replication 188 variants from the GWAS [56 variants for mucinous, 55 for endometrioid and clear cell, 53 for low-malignant potential (LMP) serous, and 24 for invasive serous EOC], selected using pre-defined criteria. Genotypes from 13,188 cases and 23,164 controls of European descent were used to perform unconditional logistic regression under the log-additive genetic model; odds ratios (OR) and 95 % confidence intervals are reported. Nine variants tagging six loci were associated with subtype-specific EOC risk at P < 0.05, and had an OR that agreed in direction of effect with the GWAS results. Several of these variants are in or near genes with a biological rationale for conferring EOC risk, including ZFP36L1 and RAD51B for mucinous EOC (rs17106154, OR = 1.17, P = 0.029, n = 1,483 cases), GRB10 for endometrioid and clear cell EOC (rs2190503, P = 0.014, n = 2,903 cases), and C22orf26/BPIL2 for LMP serous EOC (rs9609538, OR = 0.86, P = 0.0043, n = 892 cases). In analyses that included the 75 GWAS samples, the association between rs9609538 (OR = 0.84, P = 0.0007) and LMP serous EOC risk remained statistically significant at P < 0.0012 adjusted for multiple testing. Replication in additional samples will be important to verify these results for the less-common EOC subtypes.

Occupational exposure and ovarian cancer risk.

PURPOSE: Relatively little work has been done concerning occupational risk factors in ovarian cancer. Although studies conducted in occupational settings have reported positive associations, their usefulness is generally limited by the lack of information on important confounders. In a population-based case-control study, we assessed risk for developing epithelial ovarian cancer (EOC) associated with occupational exposure while accounting for important confounders. METHODS: Participants were identified through provincial population-based registries. Lifetime occupational history and information on potential confounding factors were obtained through a self-administered questionnaire. Unconditional logistic regression and the likelihood ratio test were used to assess EOC risk with each occupation (or industry), relative to all other occupations (or industries), adjusting for potential confounders including body mass index, oral contraceptive use, menopausal hormone therapy, parity, age at first childbirth, age at menarche, age at menopause, family history of breast and ovarian cancer in mother and sister(s), tubal ligation, partial oophorectomy, and hysterectomy. Occupations and industries were coded according to the Canadian Standard Occupational Classification (SOC) and Standard Industrial Classification (SIC). RESULTS: Significant excess risk was observed for several groups of teaching occupations, including SOC 27, teaching and related (adjusted OR 1.77, 95% CI 1.15-2.81) and SOC 279, other teaching and related (adjusted OR 3.11, 95% CI 1.35-8.49). Significant excess was also seen for a four-digit occupational group SOC 4131, bookkeepers and accounting clerks (adjusted OR 2.80, 95% CI 1.30-6.80). Industrial sub-groups showing significant excess risk included SIC 65, other retail stores (adjusted OR 2.19, 95 % CI 1.16-4.38); SIC 85, educational service (adjusted OR 1.45, 95% CI 1.00-2.13); and SIC 863, non-institutional health services (adjusted OR 2.54, 95% CI 1.13-6.52). CONCLUSIONS: Our study found an elevated EOC risk for teaching occupations and is the first study to observe such an increased risk after adjustment for potential confounders. Further studies with more detailed assessment of the work environment and unique lifestyle characteristics may be fruitful in elucidating this etiology.

Opportunistic salpingectomy: uptake, risks, and complications of a regional initiative for ovarian cancer prevention.

OBJECTIVE: The purpose of this study was to assess the uptake and perioperative safety of bilateral salpingectomy (BS) as an ovarian cancer risk-reduction strategy in low-risk women after a regional initiative that was aimed at general gynecologists in the province of British Columbia, Canada. STUDY DESIGN: This population-based retrospective cohort study evaluated 43,931 women in British Columbia from 2008-2011 who underwent hysterectomy that was performed with and without BS or bilateral salpingo-oophorectomy or who underwent surgical sterilization by means of BS or tubal ligation. Parameters that were examined include patient age, operating time, surgical approach, indication, length of hospital stay, and perioperative complications. RESULTS: There was an increase in the uptake of hysterectomy with BS (5-35%; P < .001) and BS for sterilization (0.5-33%; P < .001) over the study period, particularly in women <50 years old. Minimal additional surgical time is required for hysterectomy with BS (16 minutes; P < .001) and BS for sterilization (10 minutes; P < .001) compared with hysterectomy alone or tubal ligation, respectively. No significant differences were observed in the risks of hospital readmission or blood transfusions in women who underwent hysterectomy with BS (adjusted odds ratio [aOR], 0.91; 95% confidence interval [CI], 0.75-1.10; and aOR, 0.86; 95% CI, 0.67-1.10, respectively) or BS for sterilization (aOR, 0.8; 95% CI, 0.56-1.21; and aOR, 0.75; 95% CI, 0.32-1.73, respectively). From 2008-2011 the proportion of hysterectomies with BS performed by open laparotomy decreased from 77-44% with uptake in laparoscopic, vaginal, and combined procedures (P < .001). CONCLUSION: After our 2010 educational initiative, there has been a shift in surgical paradigm in our province. This cancer prevention approach does not increase the risk of operative/perioperative complications and appears both feasible and safe.

Stage II to IV low-grade serous carcinoma of the ovary is associated with a poor prognosis: a clinicopathologic study of 32 patients from a population-based tumor registry.

Low-grade serous carcinoma (LGSC) of the ovary has only recently been recognized as a disease entity distinct from the more common high-grade serous carcinoma (HGSC). When confined to the ovary, LGSC is associated with a very favorable prognosis, and chemotherapy is typically not recommended. There is little available information on the prognosis of patients with LGSC with extraovarian spread, from population-based tumor registries where there has been full pathology review. Thirty-two cases of Stage II to IV ovarian LGSC were identified in the Cheryl Brown Ovarian Cancer Outcomes Unit (1984-2000). In 19 cases, blocks were available and immunostaining for p53, p16, Ki-67, WT1, and E-cadherin was performed. Expression of these markers was then compared with a series of >400 cases of HGSC from the outcomes unit. LGSCs presented at Stage II in 10/32 cases, Stage III in 21/32 cases, and Stage IV in 1/32 cases. On follow-up, most patients died of disease, with <30% survival at 10 years. Compared with HGSCs, the LGSCs were significantly less likely to express p16 at high levels, or to show abnormal p53 expression (P=0.049 and <0.0001, respectively). Ki-67 staining indices were lower in the LGSCs (P<0.0001). There were no significant differences between LGSCs and HGSCs with respect to expression of WT1 and E-cadherin (P=0.27 and 0.62, respectively). This population-based series of LGSC with extraovarian spread at presentation had an unfavorable prognosis, similar to that of HGSC. As previously reported, LGSC shows lower tumor proliferation and fewer p53 abnormalities than in HGSC.

The impact of geographic variations in treatment on outcomes in ovarian cancer.

OBJECTIVE: There are significant regional differences in survival outcomes across British Columbia among women with ovarian cancer. The age-adjusted hazard ratio for mortality is 1.27 (95% confidence interval, 1.08-1.49) in 1 health authority region compared to the provincial mean. The objective of this study was to look at variations in the treatment of epithelial ovarian cancer among the 5 health authority regions in the province of British Columbia and determine their effect on survival. METHODS AND MATERIALS: This was a population-based retrospective cohort study of all incident cases of epithelial ovarian cancer diagnosed in British Columbia from 2005 to 2008. Health authority regions were compared with the χ(2) test for demographic and disease characteristics, as well as treatment practices including assessment by a gynecologic oncologist, rate of optimal debulking, and proportion receiving platinum-based combination chemotherapy. Multivariable Cox regression analysis evaluated the effect of covariates on survival. RESULTS: There were 854 evaluable patients. Across health authority regions, there were significant differences in disease characteristics, including the proportion with serous histotype (44.0%-60.7%, P = 0.043) and stage IIIC/IV disease (50.3%-69.4%, P = 0.0048). There were also significant differences in treatment, including the proportion of patients assessed by a gynecologic oncologist (56.8%-79.4%, P = 0.0003), rate of suboptimal debulking, (21.4%-60.2%, P = 0.0036), and the proportion receiving combination chemotherapy, (61.5%-81.9%, P < 0.0001). Cox regression model revealed that stage, grade, optimal debulking, and combination chemotherapy were significantly associated with survival. The health authority region with the highest mortality had the lowest rate of optimal debulking and combination chemotherapy. CONCLUSIONS: Differences in survival rates for ovarian cancer across British Columbia can be attributed to variations in disease characteristics and treatment, particularly rates of optimal debulking and combination chemotherapy.

Mutation of FOXL2 in granulosa-cell tumors of the ovary.

BACKGROUND: Granulosa-cell tumors (GCTs) are the most common type of malignant ovarian sex cord-stromal tumor (SCST). The pathogenesis of these tumors is unknown. Moreover, their histopathological diagnosis can be challenging, and there is no curative treatment beyond surgery. METHODS: We analyzed four adult-type GCTs using whole-transcriptome paired-end RNA sequencing. We identified putative GCT-specific mutations that were present in at least three of these samples but were absent from the transcriptomes of 11 epithelial ovarian tumors, published human genomes, and databases of single-nucleotide polymorphisms. We confirmed these variants by direct sequencing of complementary DNA and genomic DNA. We then analyzed additional tumors and matched normal genomic DNA, using a combination of direct sequencing, analyses of restriction-fragment-length polymorphisms, and TaqMan assays. RESULTS: All four index GCTs had a missense point mutation, 402C-->G (C134W), in FOXL2, a gene encoding a transcription factor known to be critical for granulosa-cell development. The FOXL2 mutation was present in 86 of 89 additional adult-type GCTs (97%), in 3 of 14 thecomas (21%), and in 1 of 10 juvenile-type GCTs (10%). The mutation was absent in 49 SCSTs of other types and in 329 unrelated ovarian or breast tumors. CONCLUSIONS: Whole-transcriptome sequencing of four GCTs identified a single, recurrent somatic mutation (402C-->G) in FOXL2 that was present in almost all morphologically identified adult-type GCTs. Mutant FOXL2 is a potential driver in the pathogenesis of adult-type GCTs.

The role of the fallopian tube in ovarian cancer.

High-grade serous carcinoma (HGSC) is the most common and lethal subtype of ovarian cancer. Research over the past decade has strongly suggested that "ovarian" HGSC arises in the epithelium of the distal fallopian tube, with serous tubal intraepithelial carcinomas (STICs) being detected in 5-10% of BRCA1/2 mutation carriers undergoing risk-reducing surgery and up to 60% of unselected women with pelvic HGSC. The natural history, clinical significance, and prevalence of STICs in the general population (ie, women without cancer and not at an increased genetic risk) are incompletely understood, but anecdotal evidence suggests that these lesions have the ability to shed cells with metastatic potential into the peritoneal cavity very early on. Removal of the fallopian tube (salpingectomy) in both the average and high-risk populations could therefore prevent HGSC, by eliminating the site of initiation and interrupting spread of potentially cancerous cells to the ovarian/peritoneal surfaces. Salpingectomy may also reduce the incidence of the 2 next most common subtypes, endometrioid and clear cell carcinoma, by blocking the passageway linking the lower genital tract to the peritoneal cavity that enables ascension of endometrium and factors that induce local inflammation. The implementation of salpingectomy therefore promises to significantly impact ovarian cancer incidence and outcomes.

Tumor type and substage predict survival in stage I and II ovarian carcinoma: insights and implications.

OBJECTIVE: An ability to predict survival is of crucial importance in determining the need for cancer therapy. Recent advances in tumor typing of ovarian carcinomas lead to a classification which is more reproducible and reflects underlying biology more accurately than grade. We tested whether updated tumor type predicts outcome for patients with low-stage ovarian carcinoma. METHODS: From a population-based cohort of 1326 women diagnosed with stage I-II ovarian carcinoma between 1984 and 2003, 652 cases were available for central pathological slide review using contemporary criteria. Six hundred thirty cases were confirmed as ovarian carcinoma. Twenty-five ovarian carcinomas of rare types were excluded leaving 605 cases for this study. Recursive partitioning analysis and univariate models were used to identify subsets with an excellent outcome, i.e., disease-specific survival at 10 years (DSS10y) > or =95%. RESULTS: Seventy-seven ovarian carcinomas of endometrioid and mucinous type, stage Ia or Ib, were associated with an excellent outcome [DSS10y=95%]. No subset of the high-grade serous type with an excellent outcome could be identified. Clear cell carcinomas of stage Ia or Ib had a favorable outcome [DSS10y=87%] compared to stage Ic-II [DSS10y=66%]. CONCLUSIONS: A subset of ovarian carcinoma patients with an excellent outcome can be identified based on tumor type (endometrioid or mucinous) and stage (Ia or Ib). Type is more reproducibly assigned than grade and identifies a larger cohort of women with stage I/II ovarian carcinoma with favorable outcomes (12.2% vs. 6.5%), and therefore is superior to grade in estimating risk of death from ovarian carcinoma.

Differences in tumor type in low-stage versus high-stage ovarian carcinomas.

Although there are recognized differences in the type of ovarian carcinomas between those tumors diagnosed at low versus high stage, there is a lack of data on stage distribution of ovarian carcinomas diagnosed according to the current histopathologic criteria from large population-based cohorts. We reviewed full slide sets of 1009 cases of 2555 patients diagnosed with ovarian carcinoma that were referred to the British Columbia Cancer Agency over a 16-year period (1984 to 2000). On the basis of the reviewed cases we extrapolated the distribution of tumor type in low-stage (I/II) and high-stage (III/IV) tumors. We then compared the frequencies with those seen in a large hospital practice. The overall frequency of tumor types was as follows: high-grade serous-68.1%, clear-cell-12.2%, endometrioid-11.3%, mucinous-3.4%, low-grade serous-3.4%, rare types-1.6%. High-grade serous carcinomas accounted for 35.5% of stage I/II tumors and 87.7% of stage III/IV tumors. In contrast, clear-cell (26.2% vs. 4.5%), endometrioid (26.6% vs. 2.5%), and mucinous (7.5% vs. 1.2%) carcinomas were relatively more common among the low-stage versus high-stage tumors. This distribution was found to be very similar in 410 consecutive cases from the Washington Hospital Center. The distribution of ovarian carcinoma types differs significantly in patients with low-stage versus high-stage ovarian carcinoma when contemporary diagnostic criteria are used, with consistent results seen in 2 independent case series. These findings reflect important biological differences in the behavior of the major tumor types, with important clinical implications.

HER2 overexpression and amplification is present in a subset of ovarian mucinous carcinomas and can be targeted with trastuzumab therapy.

BACKGROUND: The response rate of ovarian mucinous carcinomas to paclitaxel/carboplatin is low, prompting interest in targeted molecular therapies. We investigated HER2 expression and amplification, and the potential for trastuzumab therapy in this histologic subtype of ovarian cancer. METHODS: HER2 status was tested in 33 mucinous carcinomas and 16 mucinous borderline ovarian tumors (BOT)). Five cases with documented recurrence and with tissue from the recurrence available for testing were analyzed to determine whether HER2 amplification status changed over time. Three prospectively identified recurrent mucinous ovarian carcinomas were assessed for HER2 amplification and patients received trastuzumab therapy with conventional chemotherapy. RESULTS: Amplification of HER2 was observed in 6/33 (18.2%) mucinous carcinomas and 3/16 (18.8%) BOT. HER2 amplification in primary mucinous carcinomas was not associated with an increased likelihood of recurrence. The prospectively identified recurrent mucinous carcinomas showed overexpression and amplification of HER2; one patient's tumor responded dramatically to trastuzumab in combination with conventional chemotherapy, while another patient experienced an isolated central nervous system recurrence after trastuzumab therapy. CONCLUSION: HER2 amplification is relatively common in ovarian mucinous carcinomas (6/33, 18.2%), although not of prognostic significance. Trastuzumab therapy is a treatment option for patients with mucinous carcinoma when the tumor has HER2 amplification and overexpression.

Carboplatin plus paclitaxel for advanced or recurrent uterine malignant mixed mullerian tumors. The British Columbia Cancer Agency experience.

OBJECTIVES: Uterine MMMTs are aggressive malignancies that are rarely cured by purely local therapies. Effective chemotherapy is needed. The phase III proven, ifosfamide-based combinations are inconvenient and costly. Carboplatin and paclitaxel (CT) are easy to deliver and is effective against endometrial carcinoma and should be against MMMT (as they are now regarded as epithelial in nature). METHODS: A review of all women with uterine MMMT treated with CT. Paclitaxel 175 mg/m2 over 3 h preceded carboplatin (AUC 5-6) every 4 weeks for 3-6 cycles+/-subsequent pelvic irradiation. RESULTS: Twenty-eight newly diagnosed women (20 evaluable) and 12 recurrent (11 evaluable) were treated. Response rates were 60% (12 of 20, CR 5, PR 7) and 55% (6 of 11, CR 2, PR 4) with median PFS of 16 and 12 months. Dose reduction occurred in 5%, treatment delay in 10%. CONCLUSIONS: Carboplatin-paclitaxel is effective against uterine MMMT, with similar efficacy to ifosfamide combinations. It is more convenient, less costly and easy to deliver.

Better therapeutic trials in ovarian cancer.

The Ovarian Task Force of the Gynecologic Cancer Steering Committee convened a clinical trials planning meeting on October 28-29, 2011, with the goals to identify key tumor types, associated molecular pathways, and biomarkers for targeted drug intervention; review strategies to improve early-phase screening, therapeutic evaluation, and comparison of new agents; and optimize design of randomized trials in response to an evolving landscape of scientific, regulatory, and funding priorities. The meeting was attended by international clinical and translational investigators, pharmaceutical industry representatives, government regulators, and patient advocates. Panel discussions focused on disease types, early-phase trials, and randomized trials. A manuscript team summarized the discussions and assisted with formulating key recommendations. A more integrated and efficient approach for screening new agents using smaller selective randomized trials in specific disease-type settings was endorsed, together with collaborative funding models between industry and the evolving national clinical trials network, as well as efforts to enhance public awareness and study enrollment through advocacy.

Low-stage ovarian clear cell carcinoma: population-based outcomes in British Columbia, Canada, with evidence for a survival benefit as a result of irradiation.

PURPOSE: To evaluate the population-based outcomes of stage I and II ovarian clear cell carcinoma (OCCC) in a North American population treated with carboplatin/paclitaxel and abdominopelvic irradiation. PATIENTS AND METHODS: Retrospective analysis was performed of 241 patients referred in the carboplatin/paclitaxel era. Irradiation was to be used with a few defined exceptions. However, because of differing beliefs as to its effectiveness, its use was consistently avoided by specific oncologists, allowing the opportunity to study its possible effect on disease-free survival (DFS) in these concurrent cohorts. RESULTS: Five- and 10-year DFS rates were 84% and 70% for stage IA/B; 67% and 57% for stage IC; and 49% and 44% for stage II, respectively. Five- and 10-year DFS rates for those with stage IC disease based purely on rupture were similar to rates for patients with stage IA/B, at 92% and 71%, respectively. The remaining patients with stage IC had 48% 5- and 10-year DFS. Multivariate analysis using a decision tree identified positive cytology as the most important factor (72% relapse rate if positive and 27% if negative or unknown). If, in addition, the capsule surface was involved, then the relapse rate was 93%. Irradiation had no discernible survival benefit for patients with stage IA and IC (rupture alone), whereas for the remainder of patients with stage IC and stage II, it improved DFS by 20% at 5 years (relative risk, 0.5); the benefit was most evident in the cytologically negative/unknown group. CONCLUSION: DFS is similar in this North American population with early OCCC to the DFS reported in Asia. A potential benefit from irradiation was evident in a subset.

A phase II study of the MDR inhibitor biricodar (INCEL, VX-710) and paclitaxel in women with advanced ovarian cancer refractory to paclitaxel therapy.

PURPOSE: Incel (biricodar, VX-710) restores drug sensitivity to P-glycoprotein (MDR1) and multidrug-resistance-associated protein (MRP1) expressing cells. This phase II study evaluated the safety/tolerability, pharmacokinetics, and efficacy of VX-710 plus paclitaxel in women with advanced ovarian cancer refractory to prior paclitaxel therapy. EXPERIMENTAL DESIGN: Eligible patients had paclitaxel-refractory disease defined as progressive disease after a minimum of two cycles of paclitaxel (weekly or 3-week schedule) or relapsed disease within 4 months of prior paclitaxel therapy. Patients received 80 mg/m(2) paclitaxel over 3 h starting 4 h after initiation of a 24-h continuous intravenous infusion of 120 mg/m(2)/h VX-710. Cycles were repeated every 3 weeks. RESULTS: Fifty patients received treatment and 45 were evaluable for response. VX-710 + paclitaxel therapy was generally well tolerated. Myelosuppression was the principal toxicity, with a median Cycle 1 nadir absolute neutrophil count of 0.27 x 10(9) cells/L and a 47% overall incidence of Grade 4 neutropenia. Mild to moderate peripheral neuritis or neuropathy was the primary nonhematologic toxicity, affecting 62% of patients. Other nonhematologic toxicities were generally mild to moderate and reversible. Paclitaxel area under the concentration-versus-time curve (AUC) (16 +/- 5.3 microg x h/mL) during the first treatment cycle was comparable to standard 175 mg/m(2) paclitaxel administered over 3 h. Of the 3 patients who achieved partial responses, 2 had progressed during prior paclitaxel therapy. Twelve patients maintained stable disease and 14/45 (31%) of patients had CA-125 reductions of 50-90% for up to 24 weeks. The median time-to-disease progression was 10 weeks for the intent-to-treat population and 20.7 weeks for the CA-125 responders. CONCLUSIONS: The results suggest that VX-710 with paclitaxel has modest activity in paclitaxel-resistant ovarian cancer. Further research is warranted in less heavily treated patients.