PDL1-Based Nomogram May Be of Potential Clinical Utility for Predicting Survival Outcome in Stage III Breast Cancer.

Purpose: Programmed cell death ligand 1 (PDL1) has the predictive and prognostic value in a great deal of cancers. This study aims to explore the expression of PDL1 in stage III breast cancer (BC) and its correlation with clinical outcome.

Methods: The protein expression of PDL1 in tumor tissues was determined by immunohistochemistry (IHC). The correlations between PDL1 and clinicopathological variables were performed by χ²-tests or Fisher's exact tests. The Cox proportional hazards model was used for univariate and multivariate analysis of the potential prognostic factors. Survival curves were estimated based on Kaplan-Meier analyses, and Log Rank test was used to contrast factors influencing the survival outcome.

Results: On the basis of the semiquantitative scoring method for PDL1 expression, the patients were divided into low PDL1 expression group (109 cases) and high PDL1 expression group (107 cases). PDL1 expression was correlated with positive lymph nodes, positive axillary lymph nodes, postoperative radiotherapy, and CK5/6 expression (P < 0.05). The PDL1 expression in tumor tissues was discovered to be a potential prognostic risk factor with the disease-free survival (DFS) and overall survival (OS) for stage III BC. Moreover, patients with high PDL1 expression showed longer lifetime (DFS and OS) compared to those with low PDL1 expression in total patient population (P < 0.05). Moreover, the nomogram showed that the prediction line is in good agreement with the reference line for postoperative 1-, 3-, and 5-year lifetime. The DCA curve showed that the 3- and 5-year lifetime by nomogram had so much better divination of the clinical application than only by PDL1.

Conclusion: PDL1 is a latent prognostic factor in stage III BC and is closely related to some clinicopathological features. PDL1 expression in tumor tissues is significantly associated with better lifetime rate in stage III BC.