Five-year prognostic impact of pre-existing interstitial lung disease in non-small cell lung cancer patients treated with anti-PD-1 monotherapy: a retrospective analysis

Anti-programmed death 1 (PD-1) antibodies, a type of immune checkpoint inhibitor (ICI), have enhanced survival rates in non-small cell lung cancer (NSCLC). While some patients with NSCLC have pre-existing interstitial lung disease (ILD), data on the long-term safety and effectiveness of anti-PD-1 antibodies for this group are still unclear. We examined patients with advanced NSCLC who experienced recurrence after surgery or radiotherapy and received anti-PD-1 antibody monotherapy at Aichi Cancer Center Hospital from December 2015 to December 2018. The study assessed the connection between progression-free survival (PFS) and overall survival (OS) with respect to pre-existing ILD, and also investigated how ICI-induced pneumonitis impacted OS. Among the 200 patients, 35 (17.5%) had pre-existing ILD. There were no significant differences in OS between the ILD and non-ILD groups, with 5-year OS rates of 21.1% and 24.8% respectively (HR = 0.99; 95% CI, 0.66–1.48; p = 0.956). ICI-induced pneumonitis was more common in the pre-existing ILD group (40.0% vs. 12.1%, P < 0.001). A 90-day landmark analysis showed no statistically significant difference in OS between patients with and without ICI-induced pneumonitis. Although the occurrence of ICI-induced pneumonitis was common, patients with NSCLC having pre-existing ILD exhibited comparable long-term survival rates to those without ILD. The potential risks and benefits should be thoroughly assessed when contemplating ICIs for these patients.