[The importance of axillary diagnosis in breast cancer from the viewpoint of radiotherapists. The results of a retrospective study of 671 patients].

We reviewed the clinical evolution and survival of 671 post mastectomy breast cancer patients. 561 patients underwent a postoperative radiotherapy, whereas 110 did not. After grouping for N0 and N+, the median number of examined axillary lymph nodes in the not irradiated group was for N0 status three and for the N+ status eight axillary lymph nodes. In the latter group the median number of the involved axillary nodes was three. In the post mastectomy irradiated N0 group the median number of examined axillary nodes was five, whereas in the N+ group the corresponding number was seven. The median number of involved nodes was two. The majority of the N0 patients who were not postoperatively irradiated were referred to our clinic with a local recurrence. The study shows that axillary staging of the N0 group was not performed corresponding to the today's accepted oncological norms for the minimum number of axillary nodes to be examined to determine a "true" N0 axillary status. Thus, it was not a surprise to find out, for N0 patients, a dependency of the survival rate on the number of examined axillary nodes. Patients with more than nine examined nodes showed better survival rates than patients with less than five examined nodes (p less than 0.05). The irradiation of the axilla is obligatory in case of incomplete axillary dissection (less than ten negative examined nodes from level I and II and less than 18 nodes for a positive axillary dissection). The irradiation of the axilla is not indicated after a complete axillary clearance.