The Value of Breast Ultrasound in BRCA1 and BRCA2 Mutation Carriers

OBJECTIVE: BRCA1/2 mutations carriers face a lifetime risk for breast cancer of 60 to 80%. Typically, tumor incidence is high at young age and tumor growth rates are significantly elevated. On ultrasound investigation the malignancies often mimic fibroadenomas with round shape, circumscribed margins and a homogeneous internal structure leading to a BIRADS 3 classification. On this background we evaluated the efficacy of ultrasound for the early detection of breast cancer in this high risk group.METHODS: Between 01/1997-07/2008 223 BRCA1/2 mutation carriers participated in a breast cancer screening program which included semi-annual ultrasound (US) and annual mammography (MG) and MR imaging (MRI).Screening procedures started from age 25, MG at age 30. As patients consecutively joint the study women underwent 5 (median) screening rounds with a range of 1 to 22 appointments, totaling 1855 rounds of screening. All three imaging modalities were coded according to the American College of Radiology (BI-RADS classification).RESULTS: We detected 15 primary and 14 secondary contralateral BRCA-associated tumors in 27 patients. Age at diagnosis ranged from 29 to 66 years (median 41 years). BI-RADS classification IV and V enabled the detection of 9 (32%) cancers by mammography, 21 (87,5%) by US and 27 (96%) by MRI scan. Specificity added up to 100%. Three (11%) tumors were detected by the semi-annual ultrasound screen and two patients presented with interval carcinomas (16 and 8 mm in diameter) between two screening appointments. Thus, the proportion of interval cancers was 7%.CONCLUSION: Semi-annual sonography as a supplementary examination enabled us to reveal 3 additional invasive cancers (two stage pT1b, one stage pT1c). Due to the specific tumor morphology and the considerably elevated tumor doubling time mutation carriers may benefit from the addition of semi-annual ultrasound as a highly sensitive and cost-effective method.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4004.

Prevalence Rates of Pathogenic Mutations in the BRCA1 and BRCA2 Genes in Families with Different Disease Histories: Results from the German Consortium for Hereditary Breast and Ovarian Cancer

Introduction: In the German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC), a large number of families with different histories of breast and ovarian cancers was screened for pathogenic mutations in the tumor-suppressor genes BRCA1/2. We here aimed to analyse the prevalence rates of pathogenic mutations for various familial disease histories.Methods: From 1997-2009 more than 6,000 families were screened for pathogenic mutations in BRCA1/2. Mutation analysis was performed by DHPLC (denaturing high-performance liquid chromatography) pre-screening, direct sequencing of suspect fragments and MLPA (multiplex ligation-dependant probe amplification) in at least one index case of these families. Complete pedigree information over three generations was used for the analysis. All lineages within a pedigree were traced and checked for the presence of several predefined disease histories.Results: Detailed mutation prevalence rates have been determined for a variety of familial risk situations. The highest mutation prevalence rate (78%, 95%CI 67-87%) was seen in families with at least two relatives affected by pre-menopausal breast cancer and at least two affected by ovarian cancer at any age. Importantly, the presence of a single woman affected by breast and ovarian cancer or bilateral breast cancer with first breast cancer under the age of 41 was associated with a BRCA1/2 mutation prevalence of 53% (95%CI 48-59%) and 34% (95%CI 23-47%) respectively. Interestingly, low mutation prevalence rates of <10% were found in families with only one case of male breast cancer (9%, 95%CI 4-19%), and in families with three or more cases of postmenopausal breast cancer (7%, 95%CI 4-14%), the former being only BRCA2 mutations. Overall, the mutation prevalence was 27% (95% CI 26-29%) in the whole cohort.Conclusion: We provide comprehensive estimates for BRCA1/2 mutation prevalence rates that are based on a large number of families with comprehensive pedigree information. Such estimates can be used to develop cost effective screening strategies for public health care providers.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4073.

Impact of BRCA mutation status on the clinical phenotype and survival of hereditary breast cancer

Abstract #3091

Background : In a multidisciplinary program supported by the German Cancer Aid in 1996-2006 a total of 3.408 women with a family history for breast and/or ovarian cancer were genetically counselled and tested for BRCA-1 and BRCA-2 mutations.
 Methods: The mutations were detected using DHPLC and direct sequencing. The family history of breast and/or ovarian cancer was proven by collecting medical reports of family members. The statistical analysis was done using standard procedures (Kaplan-Meier-analysis, t-test, chi-square-test).
 Results: Among the women with breast cancer 566 showed a deleterious BRCA1 and 313 a BRCA2 mutation. Four women were found to have mutations in both genes and 2.525 were BRCA-1/2 negative. In accordance with the literature we found the phenotype “hormone receptor negative and grade 3” as well as the medullary subtype significantly more often in BRCA1 associated breast cancers (74% vs. 24%, 63% vs. 42% and 10% vs. 5%). The median age of onset was significantly lower in BRCA1 mutation carriers (38 yrs) compared to BRCA2 mutation carriers (45 yrs) and women tested negative for BRCA1 and BRCA2 mutations (46 yrs) as well as sporadic breast cancer cases within these families (52 yrs). The median age of the 4 women with mutations in both genes was even lower (median age 33.5 yrs). Although BRCA2 associated breast carcinomas presented in more advanced stages (N+ in 44%[118/257] compared to BRCA-1 positive in 31%[166/519], p<0.01) there was no difference in overall survival between BRCA1 and BRCA2 mutation carriers. However, BRCA1 and BRCA2 negative cases showed a significantly better survival rate compared to the women with mutations (p<0.0001). Women from families with early onset breast cancer (<35 yrs) or bilateral breast cancer (<40 yrs) had a significantly better survival (p<0.0001) than women from families with a later age of onset.
 Conclusions: The BRCA mutation status has a significant impact on the clinical phenotype of hereditary breast cancer which is important for the clinical management, counselling and prevention.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3091.