Image-based PD-L1 scoring and tumor-infiltrating lymphocytes as predictors for the response to neoadjuvant...

To investigate the predictive performance of PD-L1 expression and tumor-infiltrating lymphocytes (TILs) in pre-treatment biopsies for the response to neoadjuvant chemoimmunotherapy in non-small cell lung cancer (NSCLC).

This retrospective study included 82 NSCLC patients who received neoadjuvant chemoimmunotherapy. PD-L1 expression (tumor cell [TC%], immune cell [IC%], and combined positive score [CPS]), TILs density, and the lymphocyte-to-tumor ratio (LTR) were quantitatively assessed using digital image analysis (IA). Diagnostic performance was evaluated for major pathological response (MPR), pathological complete response (pCR), and event-free survival (EFS).

Of the 82 patients, 48 (58.5%) achieved MPR and 25 (30.5%) achieved pCR. TC%-IA and TILs density were significantly associated with pathological response. For predicting MPR, TC%-IA (AUC = 0.67) showed better performance than IC%-IA (AUC = 0.61) and CPS-IA (AUC = 0.66). Similarly, for pCR, TC%-IA (AUC = 0.59) outperformed IC%-IA (AUC = 0.55) and CPS-IA (AUC = 0.47). TILs density yielded AUCs of 0.70 for MPR and 0.69 for pCR, while LTR-IA achieved AUCs of 0.71 and 0.61, respectively. The combination of TC%-IA ≥ 1% and LTR-IA ≥ 1 further improved predictive performance, with AUCs of 0.76 for MPR and 0.67 for pCR. Prognostic analysis showed that TC%-IA ≥ 1%, CPS-IA ≥ 10, and LTR-IA ≥ 1 were significantly associated with prolonged EFS.

Image-based PD-L1 scoring on TC% combined with LTR ≥ 1 serves as a predictive biomarker for both pathological response and EFS in NSCLC patients receiving neoadjuvant chemoimmunotherapy. LTR can serve as a surrogate for TILs scoring and predicts long-term EFS.