Internal mammary nodal status is a more reliable prognostic factor than DNA ploidy and c-erb B-2 expression in patients with breast cancer.

We evaluated the relationship among DNA ploidy, c-erb B-2 oncoprotein expression, and clinicopathologic prognostic factors, especially axillary and internal mammary node metastases, and their value in estimating the prognosis in 128 patients with operable breast cancer. There were significant correlations between DNA ploidy and clinical stage, tumor size, or axillary or internal mammary lymph node metastases, and between c-erb B-2 expression and clinical stage or axillary lymph node metastases. In a univariate study, overall or disease-free survival was significantly correlated to clinical stage, tumor size, DNA ploidy, c-erb B-2 expression, and axillary and internal mammary node metastases. In a multivariate study, however, only axillary and internal mammary node metastases were recognized as independent factors on overall survival, whereas on disease-free survival, only axillary lymph node metastases were identified as an independent indicator. Since the DNA ploidy status and c-erb B-2 expression were closely correlated with the axillary and/or internal mammary lymph node metastases, they did not appear as independent prognostic factors in this small series.