Loss of heterozygosity at 17p13.3-ter, distal to TP53, correlates with negative hormonal phenotype in sporadic breast cancer.

Genetic alterations on chromosome 17p are frequent in a variety of human malignancies such as sporadic breast carcinomas. The clinico-pathological significance of it remains to be elucidated. The purpose of this study was to explore whether the allelic loss (LOH) in 17p13.3, which is suggested by the presence of tumour suppressor genes, independent of TP53, are related to current clinico-pathological criteria for characterising breast cancer. A group of sporadic breast carcinomas, with no alteration in TP53 locus, were analysed for the presence of LOH in D17S34 and D17S30/5 loci, mapped to the 17p13.3 region, distinct from and telomeric to TP53. LOH by at least one marker was observed in 13 of 47 informative cases (27.6%). Clinicopathological parameters such as age, menopausal status, histological type, tumour size, nodal status, grading, ploidy, labelling index, S-phase fraction and hormonal phenotype, were evaluated. LOH at distal 17p13.3 significantly correlated with the absence of oestrogen receptors (ER) (P=0.018), progesterone receptors (PgR) (P=0.009) and concordant absence of either ER or PgR (P=0.006). This may provide a basis for speculation as to the function of the putative tumour suppressor genes in 17p13-ter in sporadic breast cancer.