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An important role for BRCA1 in breast cancer progression is indicated by its loss in a large proportion of non‐familial breast cancers
Author(s) -
Taylor Jacqueline,
Lymboura Margarita,
Pace Paul E.,
A'hern Roger P.,
Desai Anil J.,
Shousha Sami,
Coombes R. Charles,
Ali Simak
Publication year - 1998
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/(sici)1097-0215(19980821)79:4<334::aid-ijc5>3.0.co;2-w
Subject(s) - breast cancer , immunostaining , pathology , breast carcinoma , tumor suppressor gene , staining , lymph node , medicine , immunohistochemistry , cancer , carcinoma , oncology , carcinogenesis
The presence of BRCA1 protein was determined immunohistochemically in normal and benign breast biopsies, non‐familial breast carcinomas and breast carcinomas from one or more individuals from 8 BRCA1 families. Strikingly, little staining was detected in breast carcinomas from BRCA1 families, regardless of the position or type of mutation, whereas strong immunostaining was observed in 28/28 of non‐malignant breast biopsies. Furthermore, BRCA1 staining was reduced in non‐familial breast carcinomas, since loss of nuclear BRCA1 staining was evident in 19% of non‐familial breast carcinomas whilst a similar proportion (20%) showed absence of either cytoplasmic or nuclear BRCA1 staining. Statistical analysis indicates that breast cancer is characterised by a reduction in levels of nuclear BRCA1 in familial ( p < 0.001) and non‐familial breast cancer ( p = 0.001). In non‐familial breast cancer absence of nuclear BRCA1, but not cytoplasmic BRCA1, is more common in high grade breast carcinomas ( p = 0.03) and in patients with evidence of lymph node involvement ( p = 0.05). Correlation between the absence of BRCA1 protein with high grade is consistent with previous findings of a correlation between mutations in the BRCA1 gene and high grade. Our findings provide new evidence in support of BRCA1 as a tumour suppressor protein in non‐familial breast cancer. Int. J. Cancer (Pred. Oncol.) 79:334–342, 1998. © 1998 Wiley‐Liss, Inc.