Chromosome 8 numerical aberrations in stage II invasive ductal carcinoma: correlation with patient outcome and poor...

Aberrations in chromosome 8 are common in breast cancer. However, the relationship between numerical aberrations of chromosome 8 and clinical behavior (especially prognosis) in breast cancer is not well understood. In this study, a total of 40 specimens of stage II invasive ductal carcinomas (IDCs) was analyzed by fluorescence in situ hybridization (FISH) with a chromosome 8 centromere-specific probe and DNA flow cytometry (stage IIA: 20 cases; stage IIB: 20 cases). All cases were followed for at least 5.7 yr (mean: 7.5 yr; median: 7.7 yr) after surgery or until death. Single (loss), double, and triple or more signals (gain) of chromosome 8 were found in 7.6 +/- 3.5% (range: 2-16%; median: 7%), 53.7 +/- 13.2% (range: 25-81%, median: 53%), and 38.7 +/- 13.2% (range: 17-65%, median: 38%), respectively, of tumors. The frequencies of chromosome 8 gain and disomy correlated with patient outcome (respectively p < 0.05 and p < 0.01). When median ratios of chromosome 8 loss, disomy, and gain were used as the cutoff values, the survival curves revealed that patients in the low-frequency group survived significantly longer than those in the high-frequency group for chromosome 8 gain (p < 0.05), and patients in the high-frequency group survived significantly longer than those in the low-frequency group for chromosome 8 disomy (p < 0.05). Poor prognosis was not associated with age, tumor size, lymph node metastasis, histologic type, TNM stage, estrogen-receptor status, progesterone- receptor status, or DNA ploidy. Our results suggest that the frequencies of chromosome 8 gain and disomy is a potentially useful parameter for predicting prognosis of stage II IDCs.