Allelic loss at 1p34-36 predicts poor prognosis in node-negative breast cancer

Allelic losses of specific chromosomal regions in the DNA of tumor cells, w hich imply loss of tumor suppressor genes normally resident at those loci, may become useful postoperative prognostic indicators for breast cancers th at have not yet metastasized to lymph nodes. To examine whether specific al lelic losses might correlate with postoperative disease-free survival, we t ested tumors from a cohort of 228 node-negative breast cancer patients for allelic losses at 18 microsatellite loci chosen to represent either a known armor suppressor gene or a region where genetic alterations are frequent i n breast tumors. We followed the patients clinically for 5 years or until d eath (if patient death occurred before completion of 5 years of follow-up). Patients whose tumors had lost an allele at 1p34-36 bore significantly hig her risks of postoperative recurrence than those whose tumors retained both alleles of the markers in that region [the 5-year recurrence rate was 15% among patients,vith losses versus 2% among patients with retention (P = 0.0 01)], Multivariate analysis demonstrated that allelic loss at 1p34-36 was a n independent postoperative predictor of shorter disease-free survival (haz ard ratio, 5.8; P = 0.0117), Thus, allelic losses at 1p34-36 in a tumor mig ht have a potential to serve as a negative prognostic indicator to guide po stoperative management of breast cancer patients, especially in the selecti on of high-risk women who will benefit from adjuvant chemotherapy and endoc rine therapy.