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 ost eosarcoma, small cell lung carcinoma and prostate and breast cancer. W e have studied the incidence of RE gene alterations in 96 primary brea st tumours using Southern blotting techniques. The outcome has been re lated 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-negativ e tumours and less frequently in tumours with oncogene amplification t han in tumours without oncogene amplification of HER2/neu, c-myc or 11 q13. 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-neg ative patients (P < 0.01) or smaller (<2 cm) tumours (p < 0.01), but n o 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.