Risk of Pneumonitis with the Use of Different Immune Checkpoint Inhibitors in a Mexican Population.

Purpose: The incidence of pneumonitis reported in previous trials in patients with advanced cancer and use of programmed cell death protein 1 (PD-1) immunotherapy inhibitors was 2.7-3.6%. However, none of these trials included Mexican populations.

Methods: This was a retrospective analysis involving 87 patients with advanced cancer who received PD-1 inhibitors as part of their therapy. The primary outcome was the incidence of pneumonitis after using PD-1 inhibitors. The secondary outcomes were major risk factors and radiological patterns of pneumonitis.

Results: We found 13 cases of pneumonitis, giving an overall incidence of 15%; three of the cases were high-grade (grade 3). A ground-glass pattern was the major form found by chest computed tomography scans. We did not find any significant risk factor for pneumonitis.

Conclusion: The incidence of pneumonitis secondary to treatment with PD-1 inhibitors in our Mexican population was 15%, which is 5 times higher than that found in other studies. No risk factor was identified for this increased incidence of drug-induced pneumonitis following the use of PD-1 inhibitors.