Thyroid dysfunction induced by anti-PD-1 therapy is associated with a better progression-free survival in patients with advanced carcinoma

Purpose Thyroid dysfunction is the most common immune-related adverse event during anti-programmed cell death 1 (anti-PD-1) therapy. In this study, we monitored patients with advanced malignant tumors who received anti-PD-1 therapy to observe the characteristic of anti-PD-1 therapy-induced thyroid dysfunction and its correlation with prognosis. Methods Patients with advanced carcinoma treated with anti-PD-1 therapy were evaluated for thyroid function at baseline and after treatment initiation from August 2020 to March 2022. Seventy-three patients were finally included in the study. Results Among these patients, 19 (26.03%) developed thyroid dysfunction after receiving anti-PD-1 therapy. Primary hypothyroidism and thyrotoxicosis were the most common clinical manifestation. Anti-PD-1-induced thyroid dysfunction occurred 63 (26–131) days after administration; thyrotoxicosis appeared earlier than primary hypothyroidism. In Kaplan–Meier survival analysis, the progression-free survival (PFS) of the thyroid dysfunction group was better than that of the no thyroid dysfunction group (227 (95% confidence interval (CI) 50.85–403.15) days vs 164 (95% CI 77.76–250.24) days, p = 0.026). Male patients had better PFS than female patients (213 (95% CI 157.74–268.26) days vs 74 (95% CI 41.23–106.77) days, p = 0.031). In cox proportional hazards regression model, anti-PD-1-induced thyroid dysfunction remained an independent predictor of better PFS (hazard ratio (HR) = 0.339(0.136–0.848), p = 0.021). Conclusion Thyroid dysfunction is a common immune-related adverse events in advanced cancer patients treated with anti-PD-1 therapy and predicts a better prognosis. Trial registration This study was retrospectively registered with Trial ClinicalTrials.gov (NCT05593744) on October 25, 2022.