Thyroid function abnormality induced by PD-1 inhibitors have a positive impact on survival in patients with non-small...

Thyroid function abnormality (TFA) is a common immune-related adverse event (irAEs), but the association between it and the efficacy of programmed cell death protein 1 (PD-1) inhibitor in advanced non-small cell lung cancer (NSCLC) is finitely understood.

We conducted a single center, retrospective study of advanced NSCLC patients who were treated with PD-1 inhibitors between 10 October 2016 and 1 April 2020. TFA was characterized as new onset subclinical hypothyroidism, overt hypothyroidism, subclinical hyperthyroidism and overt hyperthyroidism. Frequency of development of TFA-irAEs, and its relationship with overall survival (OS) and progression free survival (PFS) were evaluated.

In our study, 191 patients were treated with PD-1 inhibitors. Among them, forty patients (20.9%) developed TFA, of whom 10 (5.2%) presented with subclinical hypothyroidism, 15 (7.9%) with overt hypothyroidism, 6 (3.1%) with subclinical hyperthyroidism and 9 (4.7%) with overt hyperthyroidism. Survival analysis showed that the OS (16.8 months vs. 11.1 months, p < 0.001) and PFS (10.4 months vs. 5.5 months, p < 0.001) were significantly longer in patients with TFA-irAEs than in those without TFA-irAEs. In subgroup analysis of hypothyroidism and hyperthyroidism groups, similar trends were also obtained for both OS and PFS. After adjusting for potential confounding variables, patients with TFA-irAEs had a lower mortality risk (HR 0.334, 95%CI 0.196-0.571) than those without TFA-irAEs.

TFA-irAEs is associated with enhanced PD-1 inhibitor efficacy in advanced NSCLC patients and it may be a biomarker for antitumor immune response.