Pleural or pericardial metastasis: A significant factor affecting efficacy and adverse events in lung cancer patients treated with PD-1/PD-L1 inhibitors.

Background: Immunotherapy is a new paradigm for the treatment of non-small-cell lung cancer (NSCLC), and targeting the PD-1 or PD-L1 pathway is a promising therapeutic option. Although PD-1/PD-L1 inhibitors are more effective than standard chemotherapy in lung cancer, clinicians are afraid to actively use them because of hyperprogression and pseudoprogression. The aim of this study was to investigate the factors associated with tumor response and serious outcomes.

Methods: We retrospectively collected the medical records of 51 patients with advanced NSCLC who received PD-1/PD-L1 inhibitors between January 2016 and February 2018.

Results: The mean patient age was 63.9 years, and 72.5% (37/51) were male. Most (92.2%, 47/51) had received previous systemic treatment. The overall response rate was 21.6% (11/51). The response rate was significantly lower in patients with pleural or pericardial metastasis than in patients without pleural or pericardial metastasis (4.3% vs. 35.7%; P = 0.007). Patients with pleural or pericardial metastasis had a significantly higher rate of adverse events of any grade (91.3% vs. 50.0%; P = 0.002) and grade 3-5 adverse events (52.2% vs. 25.0%; P = 0.046).

Conclusion: Pleural or pericardial metastasis is a significant factor affecting the efficacy and rate of adverse events in advanced NSCLC patients treated with PD-1/PD-L1 inhibitors. Clinicians should pay attention to the use of immune checkpoint inhibitors in lung cancer patients with pleural or pericardial metastasis.