Long-term Follow-up After Interstitial Laser Thermotherapy of Breast Cancer

Aim: To review the effect of immunological changes induced by interstitial laser thermotherapy (ILT) on long-term outcome of patients with breast cancer. Patients and Methods: Twenty-four patients with invasive breast cancer were treated with ILT followed by standard surgical excision. Immunohistological reactions on immunocompetent cells were performed on specimens obtained before and after ILT. Follow-up time was 116 (range=91-136) months. Results: Significant prognostic factors were histologically-positive axillary lymph nodes and Ki67 positivity. ILT increased cytotoxic T (CD8(+)) lymphocytes within the tumor and mature dendritic cells (CD83(+)) and reduced the number of T-regulatory cells (T-reg) CD25(+)/Forkhead box p3(+) (FOXP3(+)) lymphocytes in regional lymph nodes. These changes did not correlate with prognosis. The number of CD8(+) cells within the tumor, both before and after treatment, was significantly higher in patients with recurrence than in those without recurrence (p< 0.01 and p< 0.05, respectively). Patients with recurrent disease had a lower number of CD57(+) cells in tumor-free lymph nodes than did patients without recurrence (p< 0.05). Conclusion: ILT did not have any long-term adverse effects. The clinical impact of the supposedly favourable immune changes after ILT should be examined in a larger patient population.