Reappraisal of internal mammary lymph node dissection in selected patients with invasive breast cancer.

We performed a new type of en bloc extended radical mastectomy (EXT) as a clinical trial in 118 patients from 1980 through 1985. A variety of conventional radical mastectomies (RDL) were also undertaken in 105 patients from 1973 through 1985. In this retrospective study, univariate and multivariate analyses were performed to compare the results of EXT and RDL. The univariate analysis showed that the 10-year survival rates for the EXT and the RDL groups were 86% +/- 3.3% and 77% +/- 4.2%, respectively (P = 0.073 with the Cox-Mantel test). For the subgroups stratified according to the status of axillary lymph node involvement, the EXT was significantly better in patients with one to three metastatic axillary lymph nodes (P = 0.016). The adjusted Cox regression analysis revealed that the favorable results of EXT were most encouraging in the patients with one to three metastatic axillary lymph nodes (P = 0.058). Therefore, it is suggested that an EXT may be more advantageous than RDL in selected patients with resectable invasive breast cancer.