Prognostic Value of Tumor Infiltrating Lymphocytes in Luminal B Breast Cancer Based on Multiphoton Microscopy

ABSTRACT This study investigates the prognostic value of tumor‐infiltrating lymphocytes (TILs) in luminal B breast cancer patients using multiphoton microscopy (MPM) and evaluates their association with 5‐year disease‐free survival (DFS). We obtained unlabeled MPM images from 213 patients, quantified the frequency of TILs, and assigned a TILs‐score to each patient using ridge regression analysis. In addition, compared with single CLI‐score model, the nomogram model, which integrated the TILs‐score model with CLI‐score model, further enhanced the predictive power for the luminal B subgroup. Specifically, the area under the curve (AUC) for 5‐year DFS increased from 0.740 to 0.830 and hazard ratio (HR) increased from 5.31 to 7.24 in the training cohort; in the validation cohort, AUC increased from 0.716 to 0.822 and HR increased from 3.08 to 5.01. These findings suggest that the MPM‐based TILs‐score is a robust prognostic factor for luminal B breast cancer, potentially guiding more tailored treatment protocols.