Association of Allelic Losses at 3p25.1, 13q12, or 17p13.3 with Poor Prognosis in Breast Cancers with Lymph Node Metastasis

To identify specific allelic losses that might correlate with postoperative mortality of patients with node‐positive breast carcinomas, we examined tumors from a cohort of 263 such patients, who were followed clinically for 5 years postoperatively, for allelic losses among 18 microsatellite markers. Patients whose tumors had lost an allele at 3p25.1, 13q12, or 17p13.3 had significantly higher risks of mortality than those whose tumors retained both alleles at those loci. At 3p25.1, the 5‐year mortality rate was 33.8% among patients with losses vs. 16.8% with retention (P=0.0154); at 13q12,30.3% vs. 13.0% (P=0.0241); and at 17p13.3, 30.4% vs. 16.2% (P=0.0243). Combined losses at 3p25.1 and 17p13.3 increased the predicted postoperative mortality risk by a factor of 4.9 (5‐year mortality rate of 38.2% vs. 8.0%, P=0.0006), and combined losses at 3p25.1 and 13q12 raised the predicted postoperative mortality risks by a factor of 2.9 (34.7% vs. 12.7%, P=0.0441). These data indicate that loss of heterozygosity (LOH) at any one or a pair of loci at 3p25.1, 13q12, or 17p13.3 is a significant predictor of postoperative mortality for breast‐cancer patients.