[Loss of heterozygosity at different chromosomes in patients with breast cancer]

The loss of heterozygosity (LOH) at chromosomes 3p24, 7q31, 16q24.3 and 17p13.1 was measured in 15 patients with breast cancer by means of polymerase chain reaction (PCR)-restriction fragment length polymorphisms (RFLP) or PCR-CA repeat analysis. In 36%, 36%, 50% and 56% of the informative cases, LOH was detected at 3p24, 7q31, 16q24.3 and 17p13.1 loci, respectively. All the LOH at 3p24 or 7q31 happened in stage II or III, 67% of the LOH at 3p24 or 7q31 happened in the cases with lymph node metastasis, and 67% of the LOH at 3p24 or 7q31 were found in estrogen receptor negative patients. This finding shows that the measurement of LOH at 3p24 and 7q31 may be an useful predicting marker for the prognosis of patients with breast cancer. The high percent of LOH at these four loci may also indicate the possibility of the existence of tumor suppressor genes for breast cancer.