RESPONSE TO RADIATION-THERAPY AND PROGNOSIS IN BREAST-CANCER PATIENTSWITH BRCA1 AND BRCA2 MUTATIONS

Background and purpose: The purpose of this study is to evaluate overa ll survival in BRCA1 or BRCA2 breast cancer patients, describe present ing stage, review histologic findings and evaluate response to radioth erapy. Materials and methods: A retrospective study was performed eval uating breast cancer patients with known mutations of BRCA1 or BRCA2. Patients from 12 different pedigrees were cross-referenced with the Ut ah Cancer Registry (UCR), histologic findings were verified and radiot herapy records were reviewed for acute response to treatment. Actuaria l survival calculations were performed and patients were matched for a ge, date of diagnosis and tumor size. Results: Thirty breast cancer pa tients with BRCA1 mutations were found to have 34 breast cancers (four had bilateral metachronous lesions) and 20 breast cancer patients wit h BRCA2 mutations were: found to have 22 boast cancers (two had bilate ral metachronous disease). The median age at diagnosis was 49 years (r ange 21-77 years) and 42 years (range 23-83 years), respectively, for BRCA1 and BRCA2 patients. Unusual histologic types of breast cancers w ere represented with 7% (4/56) medullary and 5% (3/56) lobular carcino mas. Complete staging was possible for 63% (35/56) of cancers. Stages I, II, III and IV represented 26, 63, 6 and 6% of cancers, respectivel y. The most severe radiation reaction was moist desquamation which was self-limiting and developed in 29% (6/21) of irradiated patients. The mean follow-up was 9.8 and 7.5 years for BRCA1 and BRCA2 cancers, res pectively. Kaplan-Meier survival analysis demonstrated 5-year survival values of 75%, for BRCA1 patients, 73% for BRCA2 patients, 70% for ma tched controls and 69% for UCR controls. No statistically significant differences were evident between the groups at 5 or 10 years. Conclusi ons: Despite their younger age at presentation, breast cancer patients harboring BRCA1 or BRCA2 mutations present at a similar stage, displa y a normal acute reaction to radiotherapy and have a similar prognosis when compared with sporadic breast cancer patients. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.