Expression differences and clinical significance of PD-L1 in lung cancer patients with different histological types and differentiation degrees.

Abstract

Objective: To investigate the expression differences of PD-L1 in non-small cell lung cancer (NSCLC) patients with different histological types and differentiation degrees.

Methods: A retrospective analysis was conducted on the clinical data of 538 NSCLC patients diagnosed at Ningbo Pathological Diagnosis Center (6 small cell lung cancer cases were excluded due to limited sample size). PD-L1 expression was detected by immunohistochemistry (clone 22C3) and evaluated by tumor proportion score (TPS). Univariate chi-square test and multivariate Logistic regression analysis were used to analyze the associations between PD-L1 expression and clinical pathological factors (gender, age, histological type, differentiation degree).

Results: PD-L1 expression showed significant gender-based differences (P = 0.000), with a higher positivity rate in male patients. No significant difference was found in PD-L1 expression among different age groups (P = 0.708). Multivariate Logistic regression analysis confirmed that histological type (OR = 2.135, 95%CI:1.526-2.990, P = 0.000) and differentiation degree (OR = 0.412, 95%CI:0.298-0.569, P = 0.000) were independent influencing factors of PD-L1 high expression in NSCLC patients. The proportion of adenocarcinoma (ADC) patients with negative PD-L1 expression was significantly higher than that of squamous cell carcinoma (SCC) patients (32.45% vs. 19.92%, P = 0.000), while the high expression rate of SCC was significantly higher than that of ADC (30.08% vs. 19.21%, P = 0.000). The negative expression rate of PD-L1 in well-differentiated tumors was the highest (45.71%, P = 0.000), and the high expression rate in poorly differentiated tumors was the highest (35.98%, P = 0.000). Among well-differentiated patients with negative PD-L1 expression, the proportion of ADC was significantly higher than that of SCC (61.11% vs. 29.41%, P = 0.023); among well-differentiated patients with low PD-L1 expression, the proportion of SCC was higher than that of ADC (52.94% vs. 38.89%, P = 0.037).

Conclusion: PD-L1 expression in NSCLC is significantly correlated with histological type and differentiation degree, which are independent influencing factors of PD-L1 high expression. SCC and poorly differentiated tumors have higher PD-L1 expression levels, suggesting that these patients may have better responsiveness to PD-1/PD-L1 inhibitor immunotherapy. The study provides more precise pathological evidence for personalized immunotherapy strategies in NSCLC patients.