[Local and regional lymph node invasion in breast cancer].

The significance and the pronostic value of nodal involvement were studied in patients suffering from mammary carcinoma over the past fifteen years at the Institute Gustave-Roussy. An average of eighteen lymph nodes per patient were examined by routine methods. In 70% of the cases there was axillary involvement as well as in 42% of the cases classified as NO. Such involvement seems to proceed step by step from the lower lymph nodes to the upper ones and is significantly more frequent when the tumor is located externally or centraly (70%) than when the tumor is located in an internal quadrant (55%). Involvement of the interpectoral chain of Rotter was found in only 12% of these cases and practically never in an isolated manner. Internal mammary chain involvement, present 25% of the cases, did not seem to be connected to a median or lateral location of the tumor. The number of involved nodes has great prognostic significance, much more so than the presence of capsular rupture or sinus histiocytosis. The prognosis is much poorer if three or more nodes are involved: the seven year survival is about 85% when 0, 1 or 2 nodes are involved, and falls to 44% when three or more are involved.