Determining the lymph node status is a diagnostic measure. It is of prognostic importance and is used for therapy planning (1). In addition, axillary lymphadenectomy also served to reduce the tumor burden. The benefit of axillary radiation therapy shows that unremoved, untreated metastases can have consequences for local control and disease-free survival (2). This suggests that any affected lymph nodes that were left were successfully treated by radiation therapy. This assumption is confirmed by the available data with the detection of lymph node metastases in higher lymphatic stations even with a low metastatic lymph node load in level I. As shown in the case of only 1, 2 or 3 affected lymph nodes in level I, level III was affected in 3.0%, 3.4% and 9.3% of the patients and the interpectoral in 2.7%, 5.4% and 7.8%. In the case of 1-3 affected lymph nodes in level I, the proportions of affected lymph nodes in level III (21/503) and in interpectoral (16/377) were both 4.2%. In the case of more than 3 affected lymph nodes in level I the proportion was 44.3% in level III and 18.4% in interpectoral. These data are similar to the results of Joshi, S. et al. (3). Their results showed a proportion of 9.4% positive lymph nodes in level III if 1-3 lymph nodes in level I and II were affected and a proportion of 53.2% in the case of 4 affected lymph nodes. In our overall results, level III was affected in 18.5% and interpectoral in 9.6% if there was a positive nodal status. Joshi et al. showed this proportion to be 27.3% and 4.7%, respectively (3). Other study groups were also able to demonstrate a level III infestation between 15% and 59% (4) (5) (6).
Altogether, in the case of only 1 affected lymph node in level I, lymph nodes metastases were detectable in the subsequent lymph node stations level II, III and interpectoral in 8% of the patients. In the case of 2 affected lymph nodes in level 1, the proportion was 15% and in the case of 3 affected lymph nodes in level I, the proportion was 20%. In the case of unaffected lymph nodes in level I, 11 of 825 patients (1.3% [based on operation frequency 1.5%]) had a positive nodal stage in level II, III or interpectoral (interpectoral). It would therefore be a false negative nodal stage. Whether a false negative rate of 1.5% justifies a conventional axillary lymphadenectomy is currently decided in the negative based on the data from the sentinel lymphadenectomy (7) (8) (9).
683 of the 825 patients with lymph node metastases had <10 affected lymph nodes, which corresponds to the nodal stage N1 or N2. The surgery of level III resulted in a change of stage from stage N2 to stage N3 in 4.1% (28 /683) of these patients due to lymph node metastases in level III (chapter 5).
A total of 170 of the 825 patients with lymph node metastases had nodal stage N3, 142 (83.5%) patients with more than 9 affected lymph nodes and 28 (16.5%) patients with <10 affected lymph nodes, which is prognostic and also possibly with therapeutic consequences.
Indicators of level III lymph node involvement in the chi-square test were tumor stage, tumor size, grading, lymphangiosis, hemangiosis and the number of affected lymph nodes in level I (≤ 3 /> 3).
The location in the inner or central quadrant was also significant for lymph node metastases in level III. This corresponds to the numbers of other published data (3). The discriminant analysis showed the number of positive lymph nodes in level I (≤3 /> 3), hemangiosis and lymphangiosis as the most important prognostic factors for lymph node metastases in level III. Exclusion of lymph node metastases in level III can be assumed at 85.3% in the absence of these factors. However, the positive predictive value in this study was 6.7%. Even if some studies showed better local control with effects on overall survival (10) (16), NSABP B-04, as the first randomized study, was not able to show a survival benefit from conventional axillary dissection (11). However, these described factors should be viewed as a particular risk for lymph node metastases and should possibly be included when considering the radiation treatment plan. Also, it should be noted, that breast cancer metastases are also known to be radio-resistant (12); and resistance rates of 8-15% must be expected (13).