Outcome and Prognostic Impact of Surgical Staging in Serous Tubal Intraepithelial Carcinoma: A Cohort Study and Systematic Review

The optimal management of breast cancer susceptibility gene (BRCA)1/2 carriers with isolated serous tubal intraepithelial carcinoma (STIC) found at risk-reducing salpingo-oophorectomy (RRSO) is unclear. The prevalence of occult carcinoma and STIC in a consecutive series of BRCA1/2 carriers undergoing RRSO is reported. The outcome of staging procedures in BRCA1/2 carriers with isolated STIC at RRSO as well as the relationship between staging, chemotherapy treatment and risk of recurrence was assessed via a systematic review of the literature. Our series included 235 BRCA1/2 carriers who underwent RRSO. Federation of Gynaecology and Obstetrics stage IA carcinoma or STIC was found at RRSO in three (1.3%) and two (0.9%) patients, respectively. A systematic review of the literature included 82 BRCA1/2 carriers with isolated STIC found at RRSO. In 13/82 (16%) cases with STIC, staging was reported. In none of these cases staging revealed more advanced disease. Recurrent disease was found in four of 36 patients with reported follow-up. The estimated risk of recurrence in patients with isolated STIC at RRSO was about 11% (95% confidence interval 3-26%) after a median follow-up of 42 months (range 7-138). No recurrences were reported in those patients with STIC at RRSO who underwent staging or received chemotherapy. We found 1.3% occult carcinoma and 0.9% STIC at RRSO in our cohort of BRCA1/2 carriers. A systematic review of the literature suggests that additional treatment after RRSO, i.e. staging and/or chemotherapy, is associated with a lower risk of recurrence. However, data on staging and follow-up are limited.

No clinical utility of KRAS variant rs61764370 for ovarian or breast cancer

OBJECTIVE

Clinical genetic testing is commercially available for rs61764370, an inherited variant residing in a KRAS 3' UTR microRNA binding site, based on suggested associations with increased ovarian and breast cancer risk as well as with survival time. However, prior studies, emphasizing particular subgroups, were relatively small. Therefore, we comprehensively evaluated ovarian and breast cancer risks as well as clinical outcome associated with rs61764370.

METHODS

Centralized genotyping and analysis were performed for 140,012 women enrolled in the Ovarian Cancer Association Consortium (15,357 ovarian cancer patients; 30,816 controls), the Breast Cancer Association Consortium (33,530 breast cancer patients; 37,640 controls), and the Consortium of Modifiers of BRCA1 and BRCA2 (14,765 BRCA1 and 7904 BRCA2 mutation carriers).

RESULTS

We found no association with risk of ovarian cancer (OR=0.99, 95% CI 0.94-1.04, p=0.74) or breast cancer (OR=0.98, 95% CI 0.94-1.01, p=0.19) and results were consistent among mutation carriers (BRCA1, ovarian cancer HR=1.09, 95% CI 0.97-1.23, p=0.14, breast cancer HR=1.04, 95% CI 0.97-1.12, p=0.27; BRCA2, ovarian cancer HR=0.89, 95% CI 0.71-1.13, p=0.34, breast cancer HR=1.06, 95% CI 0.94-1.19, p=0.35). Null results were also obtained for associations with overall survival following ovarian cancer (HR=0.94, 95% CI 0.83-1.07, p=0.38), breast cancer (HR=0.96, 95% CI 0.87-1.06, p=0.38), and all other previously-reported associations.

CONCLUSIONS

rs61764370 is not associated with risk of ovarian or breast cancer nor with clinical outcome for patients with these cancers. Therefore, genotyping this variant has no clinical utility related to the prediction or management of these cancers.

Evaluation of RAD51C as cancer susceptibility gene in a large breast-ovarian cancer patient population referred for genetic testing

Despite extensive analysis of the BRCA1 and BRCA2 genes, germline mutations are detected in <20% of families with a presumed genetic predisposition for breast and ovarian cancer. Recent literature reported RAD51C as a new breast cancer susceptibility gene. In this study, we report the analysis of 410 patients from 351 unrelated pedigrees. All were referred for genetic testing and we selected families with at least one reported case of ovarian cancer in which BRCA1&2 mutations were previously ruled out. We analyzed the coding exons, intron-exons boundaries, and UTRs of RAD51C. Our mutation analysis did not reveal any unequivocal deleterious mutation. In total 12 unique sequence variations were identified of which two were novel. Our study and others suggest a low prevalence of RAD51C mutations with an exception for some founder populations. This observation is in favor of the rare allele hypothesis in the debate over the nature of the genetic contribution to individual susceptibility to breast and ovarian cancer and further genome-wide studies in high risk families are warranted.

Efficacy of screening women at high risk of hereditary ovarian cancer: results of an 11-year cohort study

The outcome of screening and prophylactic surgery in 269 women at high risk of hereditary ovarian cancer is reported. Screening was performed using transvaginal ultrasound and serum CA125 testing. Mean follow-up was 26 months (583 person-years). A total of 113 (42%) of 269 women had a pathogenic BRCA1 or BRCA2 mutation, and 127 (47%) of 269 women underwent salpingo-oophorectomy. No occult cancers were found. In eight women having both elevated CA125 levels and abnormal ultrasound findings, a malignancy was found. Four of these cancers (one borderline, one stage Ia, one stage IIIb, and one stage IIIc ovarian or peritoneal cancer) were detected at the first screening visit. One stage IIIb and one stage IIIc cancer were detected at the second screening visit after 12 months, and two interval stage IIIc and IV cancers were detected 8 and 10 months after the first screening visit. No peritoneal carcinoma was found among those 114 women who underwent bilateral salpingo-oophorectomy with normal or benign pathology results, after a mean follow-up of 16 months (152 person-years). We conclude that the efficacy of screening women at high risk of ovarian cancer seems poor because the majority of cancers were detected at an advanced stage.