Aim: Our study examined differences in the presence of mature, DC-Lamp+ DC in the SLN and non-SLN according to the extent of metastatic involvement.
Patients and methods: Paraffin blocks of the SLN and non-SLN from patients with primary breast cancer who had undergone SLN biopsy and axillary dissection were separated into three groups: (Group A) no tumor cell involvement in the SLN and non-SLN; (Group B) isolated tumor cells or micrometastases in the SLN, and tumor cell-free non-SLN; and (Group C) macrometastases in the SLN. One section of all the SLN and non-SLN was examined with immunohistochemistry using an anti-DC-Lamp-antibody. The densest area occupied by the DC-Lamp+ cells on each slide was quantified and recorded by an electronic imaging system. In this regard, the SLN and non-SLN were compared within the patients of each group using the Wilcoxon signed rank-test (p<0.05).
Results: One hundred and fourteen SLN and 1258 non-SLN from 79 patients were examined. A significantly larger area was occupied by the DC-Lamp(+) cells in the SLN compared to the non-SLN in Groups A (p=0.024) and B (p=0.009), whereas no significant difference was found within Group C (p=0.107).
Conclusions: This study suggests that the DC-dependent immune response is altered during the process of metastasis formation and is primarily activated before and during formation of micrometastasis.