Phenotypic similarities in bilateral breast cancer.

Bilateral breast cancers that develop at similar times in an individual are likely to have been subjected to similar hormonal, environmental and genetic influences during tumourogenesis compared with metachronous tumours. As such, it is possible that tumour phenotype in synchronous bilateral breast cancer may display similar biological characteristics. The aim of this study was to identify phenotypic similarities between synchronous and metachronous bilateral breast cancers which may suggest a common origin. Thirty-three cases of synchronous and 46 cases of metachronous bilateral breast cancer that displayed similar tumour type were analysed for concordance in relation to various histological and immunohistochemical parameters. A higher level of concordance was demonstrated for synchronous cases with the highest level seen for oestrogen receptor. It is likely that this is related to similar tumourogenic pathways occurring at equivalent exposure times to various environmental and hormonal influences, although, in a proportion of cases, inherited genetic factors may play a role.

Are medullary breast cancers an indication for BRCA1 mutation screening? A mutation analysis of 42 cases of medullary breast cancer.

Recommended guidelines have limited breast cancer gene ( BRCA1 ) mutation testing to individuals with a personal or family history of early onset breast and/or ovarian cancer, and those with multiple affected close relatives. Such large breast cancer families are rare in the general population, limiting the clinical application of the BRCA1 discovery. Previous reports have suggested an association between medullary breast cancer and BRCA1 mutation carriers. To test the feasibility of using these rare histological subtypes as an alternative to epidemiological factors, 42 cases of medullary cancer unselected for family history were screened for BRCA1 point mutations and large exon rearrangements. The large majority (83%) of these patients did not have significant family of breast or ovarian cancer. Two deleterious mutations resulting in a premature stop codon, and one exon 13 duplication were found. All mutations were detected in patients with typical medullary cancer, who had family history of multiple breast and ovarian cancers. Our findings suggest that medullary breast cancers are not an indication for BRCA1 mutation screening in the absence of significant family risk factors.

Excision biopsy findings of patients with breast needle core biopsies reported as suspicious of malignancy (B4) or lesion of uncertain malignant potential (B3).

AIMS: The UK National Health Service Breast Screening Programme has proposed five categories for reporting breast needle core biopsies. The majority of cores are reported as benign (B1), normal (B2) or malignant (B5). The predictive value of the two borderline categories suspicious of malignancy (B4) and lesion of uncertain malignant potential (B3) was studied. METHODS AND RESULTS: Over a 2-year period a total of 3822 breast needle core biopsies were performed, with 2997 from symptomatic patients and 825 from women undergoing mammographic screening, including 43 B4 reports (40 patients) and 120 B3 reports (116 lesions in 115 patients). The frequencies of B4 (2.5% versus 0.7%) and B3 cores (7.3% versus 2.0%) were both higher in screening than in symptomatic patients. B4 was most commonly used for small fragments of atypical cells separate from the main core or focal atypical intraductal proliferations. The criteria for calling a core B3 were: atypical intraductal epithelial proliferations (including foci that in excision specimens would be classified as atypical ductal hyperplasia), lobular neoplasia, radial scar, papillary lesion, fibroepithelial lesion with cellular stroma and spindle cell proliferations. Excision biopsies were performed in 39 patients with B4 core and 96 with B3 core. Invasive carcinoma or ductal carcinoma in situ was seen in 33 of the patients with B4 (85%) and in 29 of those with B3 cores (25%). Some categories of B3 core were associated with a higher rate of malignancy (40% for atypical intraductal epithelial proliferations and 46% for lobular neoplasia). CONCLUSIONS: The positive predictive value for carcinoma is high following a B4 core (86%). The lesion should be excised, but definitive cancer treatment is not appropriate. In some cases a definite diagnosis of malignancy can be made on repeat core. The B3 group is more heterogeneous and has a lower rate of malignancy on further biopsy (25%). The majority of B3 lesions require excision. All these patients should be discussed at multidisciplinary meetings.