Risk-reducing salpingo-oophorectomy in women with a BRCA1 or BRCA2 mutation.

BACKGROUND: Risk-reducing salpingo-oophorectomy is often considered by carriers of BRCA mutations who have completed childbearing. However, there are limited data supporting the efficacy of this approach. We prospectively compared the effect of risk-reducing salpingo-oophorectomy with that of surveillance for ovarian cancer on the incidence of subsequent breast cancer and BRCA-related gynecologic cancers in women with BRCA mutations. METHODS: All women with BRCA1 or BRCA2 mutations identified during a six-year period were offered enrollment in a prospective follow-up study. A total of 170 women 35 years of age or older who had not undergone bilateral oophorectomy chose to undergo either surveillance for ovarian cancer or risk-reducing salpingo-oophorectomy. Follow-up involved an annual questionnaire, telephone contact, and reviews of medical records. The time to cancer in the two groups was compared by Kaplan-Meier analysis and a Cox proportional-hazards model. RESULTS: During a mean follow-up of 24.2 months, breast cancer was diagnosed in 3 of the 98 women who chose risk-reducing salpingo-oophorectomy and peritoneal cancer was diagnosed in 1 woman in this group. Among the 72 women who chose surveillance, breast cancer was diagnosed in 8, ovarian cancer in 4, and peritoneal cancer in 1. The time to breast cancer or BRCA-related gynecologic cancer was longer in the salpingo-oophorectomy group, with a hazard ratio for subsequent breast cancer or BRCA-related gynecologic cancer of 0.25 (95 percent confidence interval, 0.08 to 0.74). CONCLUSIONS: Salpingo-oophorectomy in carriers of BRCA mutations can decrease the risk of breast cancer and BRCA-related gynecologic cancer.

Outcome of preventive surgery and screening for breast and ovarian cancer in BRCA mutation carriers.

PURPOSE: To prospectively determine the impact of genetic counseling and testing on risk-reduction strategies and cancer incidence in a cohort of individuals at hereditary risk for breast and ovarian cancer. PATIENTS AND METHODS: Two hundred fifty-one individuals with BRCA mutations were identified at a single comprehensive cancer center from May 1, 1995, through October 31, 2000. Uniform recommendations regarding screening and preventive surgery were provided in the context of genetic counseling. Patients were followed for a mean of 24.8 months (range, 1.6 to 66.0 months) using standardized questionnaires, chart reviews, and contact with primary physicians. RESULTS: Frequency of cancer surveillance by physical examinations and imaging studies increased after genetic counseling and testing. Twenty-one breast, ovarian, primary peritoneal, or fallopian tube cancers were detected after receipt of genetic test results. Among 29 individuals choosing risk-reducing mastectomy after testing, two were found to have occult intraductal breast cancers. Among 90 individuals who underwent risk-reducing salpingo-oophorectomy, one early-stage ovarian neoplasm and one early-stage fallopian tube neoplasm were found. Radiographic or tumor marker-based screening detected six breast cancers, five of which were stage 0/I, one early-stage primary peritoneal cancer, and three stage I or II ovarian cancers. Six additional breast cancers were detected by physical examination between radiographic screening intervals; four of these six tumors were stage I. No stage III or stage IV malignancies were detected after genetic testing. CONCLUSION: This study provides prospective evidence that genetic counseling and testing increased surveillance and led to risk-reducing operations, which resulted in diagnosis of early-stage tumors in patients with BRCA1 and BRCA2 mutations.

Ovarian cancer risk in Ashkenazi Jewish carriers of BRCA1 and BRCA2 mutations.

PURPOSE: Several studies to date have reported ovarian cancer risk due to inherited BRCA1 and BRCA2 mutations using familial data or population-based series of probands. Familial aggregation associated with both of these methods may result in a substantial ascertainment bias. To address this, we have used a case-control design that does not involve familial aggregation to estimate the lifetime penetrance of ovarian cancer due to BRCA1 and BRCA2 mutations. EXPERIMENTAL DESIGN: A total of 382 ovarian cancer cases self-identified as being Jewish with no prior diagnosis of breast cancer were derived from two hospital-based series. In the first series, all 197 invasive epithelial ovarian cancer cases self-identified as Jewish and without a prior history of breast cancer, diagnosed and treated at Memorial Sloan-Kettering Cancer Center between 1986 and 2000, were identified. In the second series, 185 Jewish invasive epithelial ovarian cancer patients without prior breast cancer were identified in a study conducted at 11 centers in North America and Israel from 1995 to 1996. Controls were 3434 Jewish women without any prior history of breast or ovarian cancer from a large study of genotyped volunteers of Jewish origin in the Washington, D. C. area recruited by investigators at the National Cancer Institute. The cases and controls were genotyped for three Ashkenazi Jewish founder mutations, namely 185delAG and 5382insC in BRCA1 and 6174delT in BRCA2. The lifetime penetrances were estimated using the odds ratios, mutation prevalence in the controls, and ovarian cancer incidence rates in the general American population obtained from the Surveillance, Epidemiology and End Results database adjusted for the incidence of ovarian cancer following breast cancer. RESULTS: Mutations were identified in 147 cases and 62 controls. The estimated penetrances at age 70 years were 37% (95% confidence interval, 25-71%) for a BRCA1 mutation and 21% (95% CI, 13-41%) for a BRCA2 mutation. CONCLUSIONS: The lifetime penetrances of BRCA1 mutations are lower than estimates obtained using familial data with multiple affected members but larger than estimates from some population-based proband series. The lifetime penetrance estimate of a BRCA2 mutation is in the range reported by some of the studies based on familial data. These results could have implications for clinical counseling, surgical interventions, and screening recommendations in women carrying these founder mutations.

Frequency of CHEK2*1100delC in New York breast cancer cases and controls.

BACKGROUND: The 1100delC CHEK2 allele has been associated with a 1.4-4.7 fold increased risk for breast cancer in women carrying this mutation. While the frequency of 1100delC was 1.1-1.4% in healthy Finnish controls, the frequency of this allele in a North American control population and in North American breast cancer kindreds remains unclear. METHODS: We genotyped 1665 healthy New York volunteers and 300 cases of breast cancer for the CHEK2*1100delC. RESULTS: The overall frequency of the 1100delC was 3/300 (1.0%) among all cases with either a family history of breast cancer (n = 192) or a personal history of breast cancer (n = 108, of which 46 were bilateral, 46 unilateral, and 16 were male breast cancer cases), compared to a frequency of 5/1665 (0.3%) in healthy controls (p = 0.1). There was no difference in allele frequency among Ashkenazi and non-Ashkenazi controls. CONCLUSION: The relatively low breast cancer penetrance of this allele, along with the low population frequency, will limit the clinical applicability of germline testing for CHEK2*1100delC in North American kindreds.

Epithelial lesions in prophylactic mastectomy specimens from women with BRCA mutations.

BACKGROUND: It has been suggested that BRCA-associated breast carcinoma may often lack a detectable preinvasive phase. To investigate this hypothesis, the authors compared the prevalence of histopathologic lesions in prophylactic mastectomy (PM) specimens from women with BRCA mutations and in mastectomy specimens obtained at autopsy from an age and race-matched comparison group without a known cancer predisposition. METHODS: All specimens from women with a deleterious BRCA1 or BRCA2 mutation who participated in an ongoing follow-up study and underwent PM at Memorial Sloan-Kettering Cancer Center between November 1, 1987 and May 31, 2001 were reviewed. For each case, breast tissue from two age and race-matched women without a known cancer predisposition was also reviewed. The prevalence of benign, premalignant, and cancerous lesions was compared. RESULTS: Mastectomy specimens from 24 cases and 48 comparison subjects were reviewed. Ductal carcinoma in situ (DCIS), atypical ductal hyperplasia (ADH), and atypical lobular hyperplasia (ALH) were all more common in PM specimens from women with BRCA mutations than in those from the comparison group. The odds ratio for the detection of any high-risk lesion (DCIS, lobular carcinoma in situ, ADH, or ALH) in specimens from BRCA mutation carriers was 12.7 (95% confidence interval, 3.1-52.4; P < 0.001). CONCLUSIONS: Lesions associated with an increased risk of subsequent malignancy are more common in PM specimens from women with BRCA mutations than in breast tissue obtained at autopsy from unaffected women without a known predisposition. This finding suggests that hereditary breast carcinoma has a preinvasive phase that may be detectable with aggressive surveillance.

A biochemical analysis demonstrates that the BRCA1 intronic variant IVS10-2A--> C is a mutation.

Sequence analysis of cDNA from an asymptomatic patient belonging to a high-risk breast cancer family carrying the genetic variant BRCA1 IVS10-2A-->C revealed that functional BRCA1 mRNA was derived from only one of the patient's chromosomes. The other chromosome produced an aberrant RNA splicing transcript that deleted exon 11. Analysis of the patient's genomic DNA demonstrated that the chromosome producing the non-functional mRNA carried the genotype BRCA1 IVS10-2A-->C. This transversion disrupts a highly conserved base in the consensus splice acceptor motif. These results support the conclusion that BRCA1 IVS10-2A-->C is a mutation that confers predisposition to breast and ovarian cancer.