Background: Emphysema and chronic obstructive pulmonary disease (COPD) are well known independent risk factors for lung cancer. However, the developmental mechanisms between emphysema/COPD and lung cancer remain unknown. The purpose of this study was to evaluate PD-L1, FGFR1, PIK3CA, PTEN, and p16 expression in squamous cell carcinoma (SCC) associated with emphysema/COPD.
Methods: A total of 59 patients with squamous cell lung carcinoma (SCC) resected between 2008 and 2012 were retrospectively reviewed. Emphysema was assessed according to the Goddard score. Total severity was divided into none-mild (0-7), moderate (8-15), and severe (≥ 16). Local severity around the existing tumor was divided into no emphysema (0) and presence of emphysema (1-4). COPD severity was based on the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. PD-L1, FGFR1, PIK3CA, PTEN, and p16 expression were evaluated by immunohistochemistry (IHC). Expression level was classified as tumor cells (TC) 3 (≥ 50%), TC2 (5-49%), TC1 (1-4%), or TC0 (< 1%), and as tumor-infiltrating immune cells (IC) 3 (≥ 50%), IC2 (5-49%), IC1 (1-4%), or IC0 (< 1%) for PD-L1. Expression level was compared between none-mild/moderate-severe total emphysema, no/presence of local emphysema, no COPD/COPD, and GOLD 1/GOLD 2, 3.
Results: PD-L1 expression was significantly correlated with severity of emphysema in TC0, 1, 2 vs. TC3 (P = 0.012). PD-L1 was significantly higher inversely in none-mild emphysema compared to moderate-severe (95% CI, 0.061-5.852, P = 0.045). There were no other significant associations between PD-L1, FGFR1, PIK3CA, PTEN, and p16 expression and total/local severity of emphysema or presence of COPD/GOLD stage.
Conclusions: PD-L1 expression in SCC was correlated with severity of emphysema in TC0, 1, 2 vs. TC3 and more frequent in none-mild emphysema than moderate-severe emphysema.
Keywords: COPD; Emphysema; Lung squamous cell carcinoma; PD-L1.