E.J. Meijers-Heijboer

Survival and tumour characteristics of breast-cancer patients with germline mutations of BRCA1

BACKGROUND Hereditary breast cancer has been associated with mutations in the BRCA1 and BRCA2 genes and has a natural history different from sporadic breast cancer. We investigated disease-free and overall survival for patients with a proven BRCA1 alteration. METHODS We estimated disease-free and overall survival for 49 Dutch patients from 19 consecutive families with a proven specific BRCA1 mutation and one family with strong evidence for linkage to the BRCA1 gene. We compared clinical outcome and data on tumour size, histology, axillary nodal status, contralateral breast cancer, and oestrogen-receptor and progesterone-receptor status with those of 196 patients with sporadic breast cancer, matched for age and year of diagnosis. FINDINGS Disease-free survival for BRCA1 and sporadic patients at 5 years was 49% (95% CI 33-64) and 51% (43-59), respectively (p=0.98). Overall survival at 5 years was 63% (47-76) and 69% (62-76), respectively (p=0.88). Recurrence and death rates did not differ significantly between groups. Hazard ratios for recurrence and death among BRCA1 patients were 1.00 (0.65-1.55) and 1.04 (0.63-1.71) relative to sporadic patients (p=0.88), and these did not differ significantly after adjustment for prognostic factors. Patients with BRCA1-associated breast cancer had twice as many progesterone-receptor-negative tumours (p<0.005) and development of contralateral breast cancer was four to five times as frequent as in the sporadic group (p<0.001). INTERPRETATION We showed that disease-free and overall survival were similar for sporadic and hereditary breast cancer in the presence of different tumour characteristics, which has implications for screening prophylactic therapy, and different treatments of hereditary breast cancer.

SURVIVAL AND TUMOUR CHARACTERISTICS OF BREAST-CANCER PATIENTS WITH GERMLINE MUTATIONS OF BRCA1

Summary Background Hereditary breast cancer has been associated with mutations in the BRCA1 and BRCA2 genes and has a natural history different from sporadic breast cancer. We investigated disease-free and overall survival for patients with a proven BRCA1 alteration. Methods We estimated disease-free and overall survival for 49 Dutch patients from 19 consecutive families with a proven specific BRCA1 mutation and one family with strong evidence for linkage to the BRCA1 gene. We compared clinical outcome and data on tumour size, histology, axillary nodal status, contralateral breast cancer, and oestrogen-receptor and progesterone-receptor status with those of 196 patients with sporadic breast cancer, matched for age and year of diagnosis. Findings Disease-free survival for BRCA1 and sporadic patients at 5 years was 49% (95% CI 33–64) and 51% (43–59), respectively (p=0·98). Overall survival at 5 years was 63% (47–76) and 69% (62–76), respectively (p=0·88). Recurrence and death rates did not differ significantly between groups. Hazard ratios for recurrence and death among BRCA1 patients were 1·00 (0·65–1·55) and 1·04 (0·63–1·71) relative to sporadic patients (p=0·88), and these did not differ significantly after adjustment for prognostic factors. Patients with BRCA1-associated breast cancer had twice as many progesterone-receptor-negative tumours (p<0·005) and development of contralateral

Effectiveness of Breast Cancer Surveillance in BRCA1/2 Gene Mutation Carriers and Women With High Familial Risk

PURPOSE Women with a high breast cancer risk due to a familial predisposition may choose between preventive surgery and regular surveillance. The effectiveness of surveillance in high-risk women and especially BRCA1/2 mutation carriers is unknown. We present first results from a single large family cancer clinic. PATIENTS AND METHODS Women with breast cancer risk over 15% were examined by physical examination every 6 months and mammography every year. Detection rates and screening parameters were calculated for the total group and separately for different age and genetic risk groups. RESULTS At least one examination was performed in 1,198 women: 449 moderate and 621 high-risk women and 128 BRCA1/2 mutation carriers. Within a median follow-up of 3 years, 35 breast cancers were detected (four ductal carcinoma-in-situ; 31 invasive tumors); the average detection rate was 9.7 per 1,000. Detection rates (95% confidence interval) for moderate and high-risk women and BRCA1/2 carriers were 3.3 (1.1 to 8.6), 8.4 (5.4 to 13.2), and 33 (17 to 63) per 1,000 person-years, respectively. The ratio of observed cases versus breast cancers expected in an average-risk population of comparable age was 2.7, 7.0 and 23.7 respectively. Overall, node negativity was 65%; 34% of primary tumors were less than 10 mm; sensitivity was 74%. Results with respect to tumor stage and sensitivity were less favorable in BRCA1/2 carriers and in women under the age of 40. CONCLUSION It is possible to identify young women at high risk for breast cancer. The number of cancers detected was significantly greater than expected in an age-matched average-risk population and related to the risk category. Overall, screening parameters were comparable to population screening data, with less favorable results in the youngest age group (< 40) and BRCA1/2 carriers.

Presymptomatic DNA testing and prophylactic surgery in families with a BRCA1 or BRCA2 mutation

BACKGROUND Germline mutations in the BRCA1 and BRCA2 genes highly predispose to breast and ovarian cancer. In families with BRCA1 or BRCA2 mutations, identification of mutation carriers is clinically relevant in view of the options for surveillance and prevention. METHODS We assessed presymptomatic DNA testing and prophylactic surgery in 53 consecutive families presenting to the Rotterdam Family Cancer Clinic with a known BRCA1 or BRCA2 mutation. We identified predictors for DNA testing and prophylactic surgery with univariate and multivariate analysis. FINDINGS 682 unaffected individuals with a 50% risk (275 women and 271 men) or with a 25% risk (136 women) for carrying a mutation were identified and offered a DNA test. Presymptomatic DNA testing was requested by 48% (198 of 411) of women and 22% (59 of 271) of men (odds ratio for difference between sexes 3.21 [95% CI 2.27-4.51]; p<0.001). In women, DNA testing was significantly more frequent at young age, in the presence of children, and at high pre-test genetic risk for a mutation. Of the unaffected women with an identified mutation who were eligible for prophylactic surgery, 51% (35 of 68) opted for bilateral mastectomy and 64% (29 of 45) for oophorectomy. Parenthood was a predictor for prophylactic mastectomy but not for prophylactic oophorectomy. Age was significantly associated with prophylactic oophorectomy, but not with prophylactic mastectomy, although there was a tendency towards mastectomy at younger ages. INTERPRETATION In a clinical setting, we show a high demand for BRCA1 and BRCA2 testing by unaffected women at risk, and of prophylactic surgery by unaffected women with the mutation. Young women with children especially opt for DNA testing and prophylactic mastectomy.