Tumor-infiltrating lymphocyte volume is a better predictor of neoadjuvant therapy response and overall survival in triple-negative invasive breast cancer

Triple-negative breast cancer (TNBC) has an aggressive behavior, limited therapeutic options, and high mortality rate. Neoadjuvant chemotherapy is a standard treatment for TNBC, and patients with pathological complete response (pCR) have a favorable outcome. We conducted a comprehensive evaluation of cancer clinicopathological parameters and correlated these parameters with the pCR rate and the overall survival. Fifty-eight patients with TNBC of no special type who underwent breast biopsy, neoadjuvant therapy, and mastectomy in our institution during 2005-2016 were included in this study. Among the 58 TNBC patients, 26 (45%) achieved pCR, and 32 (55%) had residual disease. The study parameters included age, histologic grade, clinical stage, mitotic count, Ki-67 proliferation index, stromal ratio, stromal type, tumor necrosis, stromal tumor-infiltrating lymphocytes (TILs), tumor intraepithelial lymphocytes, and tumor-infiltrating lymphocytes volume (TILV). Whereas most factors did not affect pCR, stromal TILs and TILV showed significant correlation with pCR (P = .01 and P = .0008, respectively). In the residual disease group, all factors showed no significant differences before and after neoadjuvant chemotherapy, except for tumor sizes. Lastly, pCR, TILs, and TILV were all significantly correlated with the overall survival, with P = .028, .029, and .015, respectively. In summary, we proposed a new concept of TILV to precisely evaluate the tumor immunity, and our data showed that TILV had a better predictive value than TILs for the pCR and the overall survival in TNBC.