ASSOCIATION BETWEEN RB-1 GENE ALTERATIONS AND FACTORS OF FAVORABLE PROGNOSIS IN HUMAN BREAST-CANCER, WITHOUT EFFECT ON SURVIVAL

The retinoblastoma (RE) tumour suppressor gene has been associated not only with retinoblastoma but also with several other tumours like osteosarcoma, small cell lung carcinoma and prostate and breast cancer. We have studied the incidence of RE gene alterations in 96 primary breast tumours using Southern blotting techniques. The outcome has been related with patient and tumour characteristics, oncogene amplifications, p53 mutations and prognosis. RE gene alterations were found to occur more frequently in estrogen receptor (ER)-positive than in ER-negative tumours and less frequently in tumours with oncogene amplification than in tumours without oncogene amplification of HER2/neu, c-myc or 11q13. RE gene alteration was observed in tumours both with and without a p53 gene mutation. Data on 87 patients (mean age, 59.6 years; median follow-up, 108 months) and RE gene alterations revealed a significant association between the frequency of RE gene alterations and node-negative patients (P < 0.01) or smaller (<2 cm) tumours (p < 0.01), but no relation with age, differentiation grade or (relapse-free) survival. Patients with and without RE gene alterations showed the same relapse-free and overall survival. (C) 1995 Wiley-Liss, Inc.