Background: The present study was undertaken to analyze the prognostic value of loss of heterozygosity (LOH) at 13q12-13, 17q21 and 17p13, harboring BRCA2, BRCA1 and p53 to predict the clinical course of sporadic breast cancer patients.
Materials and methods: LOH analysis was performed by PCR amplification of genomic DNA using nine microsatellite markers. Fifty-three sporadic breast cancer patients were followed clinically for a median of 55 months. Disease-free and overall survival was documented as the endpoint for statistical evaluation.
Results: Patients presenting with LOH in their tumor samples at at least one of the loci examined were found to have a reduced overall survival time compared to those retaining heterozygosity (61% versus 48%). Focusing on the three target regions, patients with LOH at the BRCA2 locus died earlier compared to patients retaining heterozygosity (69% versus 50%) and, in addition, BRCA2 LOH-positive patients showed a shorter metastasis-free interval (30 versus 37 months). In a multivariate analysis, LOH at the 13q12-13 locus was found to be a significant predictor for reduced long-term survival (risk ratio 2.33, 95% C.I., 1.0-5.3; p<0.05) and earlier metastases manifestation (risk ratio 2.32, 95% C.I., 1.0-5.3, p<0.05).
Conclusion: Allelic loss at the BRCA2 locus may be of use as a negative predictor for metastases-free and overall survival.