PROGNOSTIC ROLE OF RESIDUAL TUMOR FEATURES IN HER2-NEGATIVE BREAST CANCER

Abstract

Theanalysis of thetreatment results of 59patients with TNBC and 56patients with LBBC with stage IIB-IIIB who received NACT was performed. Thelevels of TILs and their subpopulations (FOXP3+, CD4+, CD8+) in patients at thetime of diagnosis in core-needle biopsy material and in residual tumor in postoperative material were studied by immunohistochemical method. Therisk of recurrence in patients with LBBC who received NACT before surgery is associated mainly with 4factors: FOXP3+ lymphocytes, Ki-67index in residual tumor, thenumber of affected axillary lymph nodes after NACT and viable residual tumor volume. Analysis of thetreatment outcome in patients with TNBC revealed that thelack of pathologic complete response (pCR) after NACT increases therisk of disease recurrence by 2.9times, 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 thepresence of residual tumor in patients with TNBC after NACT increases therisk of death from this disease by 2.7times (95% CI 1.0-7.1; p = 0.05). Increased intratumoral and stromal CD8+ lymphocyte counts in theresidual tumor after NACT significantly reduces therisk 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 thenon-pCR group reduces by half therisk of death from TNBC, HR = 0.5 (95% CI 0.3-1.0; p = 0.05). Theresults of our study indicate a favorable prognostic value of TILS in residual tumor in TNBC.It is also reasonable to include thedetermination of thelevel of FOXP3+lymphocytes in theresidual tumor in thestandard algorithms for stratification of risk groups.