Association between pleurodesis before immunotherapy and pneumonitis in non-small cell lung cancer

Immune checkpoint inhibitors are important in the treatment of advanced non-small cell lung cancer, with pneumonitis being a prevalent complication. Pneumonitis is a recognized adverse event of pleurodesis in lung cancer patients with pleural effusion. However, the association between pleurodesis and pneumonitis in patients with immunotherapy remains unclear.

This retrospective cohort study used nationwide administrative claims data in Japan. Patients aged ≥18 years who underwent immunotherapy for newly diagnosed non-small cell lung cancer between December 2015 and January 2023 were included in the study. Patients who used talc or OK-432 within 60 days prior to immune checkpoint inhibitors treatment were defined as having undergone pleurodesis. The incidence rates of pneumonitis in patients with and without pleurodesis were compared using cumulative incidence functions against time, and by conducting a Fine-Gray analysis to account for death as a competing risk factor for pneumonitis incidence.

Among the 16,538 patients with non-small cell lung cancer who received immune checkpoint inhibitors, 509 underwent pleurodesis. The incidence of pneumonitis was higher in patients who underwent pleurodesis than in those who did not. The sub-distribution hazard ratio quantified by Fine-Gray analysis was 1.168 (95 % confidence intercal, 1.062-1.286).

Pleurodesis before immunotherapy in patients with advanced non-small cell lung cancer was associated with an increased incidence of pneumonitis.