[Prognostic value of lympho node micrometastases detected by immunohistochemistry. Study of 168 cases of breast cancer with a 10-year follow-up].

The authors reported a retrospective pathological study of 168 patients classified PT2N- treated by Patey mastectomy completed by axillary and internal mammary lymph node removal. The size of micrometastases ranged from 0.012 to 0.87 millimeters. All 2800 lymph nodes were examined, using successively HPS and IHC procedures. Detection of micrometastases has been improved by immunohistochemical staining on paraffin embedded sections using anticytokeratin MAb clone antiKL1. The 168 patients were divided into two groups. The first one included 31 patients IHC+ out of 168 (18.5%); there were 47 micrometastatic nodes with negatives nodes out of 2800 (1,67%). The second group included 137 patients (81.5%) out of 168 with negative nodes. If we consider the PT2N-clinical status, it appears a percentage of 16 to 20% of patients developing recurrence within ten years after surgical treatment. There was no significant difference concerning the disease--free survival at ten years. Variability in metastatic node involvement spread led us to distinguish 3 subgroups of uneven prognostic value. The relative risk of relapse ranged from 1 (ICH + 1) to 1.94 (ICH + 2 and 3) merged. Do PT2N- group with recurrence and ICH + group concern the same patients? We cannot statistically prove that micrometastatic nodes are a bad prognostic factor by further studies which are required.