Clinicopathological and prognostic value of TIL and PD L1 in triple negative breast carcinomas

Triple negative breast cancer (TNBC), a highly aggressive subtype of breast cancer, accounts for 15 % of all diagnosed breast cancers. This group, which has the worst clinical outcome, high recurrence rate and poor prognosis, does not benefit from specific treatment. Therefore, there is a need to develop more effective biomarker and therapeutic strategies especially for this group. A positive level of immunity has been found to be associated with patient survival in various organ cancers. More specifically, tumor infiltrating lymphocytes (TIL) have been documented to have strong prognostic value. The programmed cell death 1 (PD 1) protein on the surface of T lymphocytes is activated by the Programmed cell death ligand 1 (PD-L1) protein on the cancer cell surface. PD- L1 is thought to form a pathway that results in suppression of antitumor responses when activated. Patients with breast cancer (BC) who underwent resection without neoadjuvant chemotherapy between 2010 and 2020 were included in this study. Of the 302 BCs examined, 21 constitute the group with TNBC. In our study, the mean age of the Triple positive breast cancer (TPBC) and TNBC groups was similar (55.67 ± 12.61 vs. 53.23 ± 8.21, p = 0.384). There was no significant correlation between TPBC and TNBC and tumor size, lymph node, histological grade, and PD-L1 positivity in the center of the tumor (all p-value >.05). It was observed that tumor stage was higher in patients with TNBC than in patients with TPBC (19 % vs. 1.1 %, p = .002). The Ki 67 proliferation index was found to be higher in patients with TNBC than in patients with TPBC (90.5 % vs. 41.8 %, p .001). Although not statistically significant, clinically, CD 3 and CD 8 immune scores with high tumor margin were higher in patients with TNBC than in patients with TPBC (90.4 % vs, 9.6 % and 85.7 % vs. 14.3 %, respectively). Positive expression of PD-L1 at the tumor margin was significantly higher in patients with TNBC than patients with TPBC (20.3 % vs, 52.4 %, p = .002). By Kaplan-Meier analysis, the survival distribution of CD 3 and CD 8 immunoscore, tumor central and margin PD-L1 values were compared. Mean follow-up was 136.18 months (range, 1 - 144 months); and the 10-year Overall Survival (OS) estimate for the population was 90.9 % (95 % CI, 85.5 - 96.7). In this study, this difference was not statistically significant according to the log-rank test. In this study, we aimed to evaluate the relationship between CD 3, CD 8 T lymphocyte immune score and PD-L1 expression at the tumor center and margin in TNBC, the prognostic value and clinicopathological significance of this relationship.