LAUSR

The aim of the study was to examine the prognostic value of immunobiological markers (tumor-infiltrating lymphocytes (TILs) and their subpopulations) in residual tumor after neoadjuvant chemotherapy (NACT) completion in patients with triple negative (TNBC) and luminal B HER2-neu negative breast cancer (LBBC). MATERIALS AND METHODS The analysis of the treatment results of 59 patients with TNBC and 56 patients with LBBC with stage IIB-IIIB who received NACT was performed. The levels of TILs and their subpopulations (FOXP3+, CD4+, CD8+) in patients at the time of diagnosis in core-needle biopsy material and in residual tumor in postoperative material were studied by immunohistochemical method. RESULTS The risk of recurrence in patients with LBBC who received NACT before surgery is associated mainly with 4 factors: FOXP3+ lymphocytes, Ki-67 index in residual tumor, the number of affected axillary lymph nodes after NACT and viable residual tumor volume. Analysis of the treatment outcome in patients with TNBC revealed that the lack of pathologic complete response (pCR) after NACT increases the risk of disease recurrence by 2.9 times, hazard ratio (HR) = 2.9 (95% confidence interval (CI) 1.4-6.1; p = 0.005) compared with patients in which pCR was achieved after NACT. It was also found that the presence of residual tumor in patients with TNBC after NACT increases the risk of death from this disease by 2.7 times (95% CI 1.0-7.1; p = 0.05). Increased intratumoral and stromal CD8+ lymphocyte counts in the residual tumor after NACT significantly reduces the risk of death from TNBC, HR = 0.6 (95% CI 0.5-0.9; p = 0.01) and HR = 0.6 (95% CI 0.4-0.9; p = 0.008), respectively. Increase in intratumoral CD4+ lymphocytes in residual tumor in the non-pCR group reduces by half the risk of death from TNBC, HR = 0.5 (95% CI 0.3-1.0; p = 0.05). CONCLUSION The results of our study indicate a favorable prognostic value of TILS in residual tumor in TNBC. It is also reasonable to include the determination of the level of FOXP3+ lymphocytes in the residual tumor in the standard algorithms for stratification of risk groups.