[The significance of c-erbB-2 and int-2 gene alterations and DNA ploidy pattern for aggressiveness of breast cancer].

We have analyzed amplification of the c-erbB-2 and int-2 genes, and restriction fragment length polymorphisms (RFLPs) of the int-2 gene in 105 primary breast carcinomas. In 90 of 105 samples, overexpression of the c-erbB-2 protein and the DNA ploidy pattern were also analyzed. Amplification of the c-erbB-2 and int-2 gene was found in 27% and in 17%, respectively. No statistical correlation between c-erbB-2 and int-2 genes amplification was observed. Overexpression of the c-erbB-2 protein was detected in 28% of samples. A correlation was observed between amplification of the c-erbB-2 gene and positive nodal status. Amplification of the int-2 gene showed no correlation with clinicopathological parameters, except that a significantly higher incidence of amplification was observed in breast carcinoma with more than 4 positive lymph nodes. Genotypes of the int-2 gene identified by RFLPs analysis revealed no correlation with clinicopathological parameters. DNA ploidy pattern, which showed neither correlation with c-erbB-2 nor int-2 genetic alterations, was associated with tumor size and TNM classification. Our result suggests that analysis of genetic alterations of the c-erbB-2 and int-2 genes and the DNA ploidy pattern may be a useful adjunct in the assessment of aggressiveness of breast carcinoma.