Frequency of chromosome 7 gain in human breast cancer cells: correlation with the number of metastatic lymph nodes and prognosis.

Abstract

Trisomy 7 has been reported in various malignant neoplasms, but there are no reports in breast cancer. In order to evaluate the contribution of chromosome 7 gain to breast cancer, we investigated the relationship of numerical abberation of chromosome 7 with clinicopathological variables and prognosis in seventy-nine breast cancer cases (invasive carcinomas) using the technique of fluorescence in situ hybridization (FISH) on paraffin-embedded sections. A significant correlation of the frequency of cells with extra copies of chromosome 7 (percent polysomy 7 cell score) was found with tumor size, regional lymph node status, tnm stage, histological extension, estrogen receptor (ER), and DNA ploidy. The number of metastatic lymph nodes was positively correlated with percent polysomy 7 cell score (correlation coefficient=0.623, p < 0.01). Furthermore, cases with a high percent polysomy 7 cell score had a shorter disease-free survival and overall survival times, especially in the lymph node-positive group. It was demonstrated that percent polysomy 7 cell value was closely associated with lymph node metastasis and prognosis and might be a useful prognostic predictor of breast cancer patients.