ALLELIC LOSS ON DISTAL CHROMOSOME-17P IS ASSOCIATED WITH POOR-PROGNOSIS IN A GROUP OF BRAZILIAN BREAST-CANCER PATIENTS

We examined loss of heterozygosity (LOH) for two loci on chromosome 17 p (D17S5 and TP53), and erbB-2 gene amplification, in primary breast c ancers from 67 Brazilian patients. We identified two distinct regions of LOH on chromosome 17p, one spanning TP53 and the other a more telom eric region (D17S5). Based on a short-term follow-up, Kaplan-Meier ana lyses of patients' disease-free survival showed that patients with LOH for D17S5, but retaining heterozygosity for TP53, were at higher risk of recurrence (P = 0.007) than those who retained heterozygosity for D17S5. Bivariate analyses indicated that patients with LOH for D17S5 a lone had an increased risk of recurrence (hazard ratio = 7.2) over pat ients with erbB-2 amplification (hazard ratio = 3.7), when compared wi th patients with neither alteration (hazard ratio = 1.0). Further, lym ph node-positive patients whose tumours had both LOH for D17S5 and erb B-2 gene amplification had a higher risk of recurrence than patients w hose tumours had neither of these genetic alterations. Our data confir m previous reports of a putative tumour-suppressor gene, distinct from TP53, on distal chromosome 17p which is associated with breast cancer . They further suggest that LOH for loci in this region may provide an independent indicator to identify patients with poor prognosis.