Prevalence of Various Endocrinopathies Resulting from Use of Immune Checkpoint Inhibitors - A Prospective Study from a Tertiary Care Centre in India.

Introduction: Immune checkpoint inhibitors (ICIs) have revolutionised cancer treatment but are associated with agent-specific spectra of endocrine-related adverse events (irAEs). Data on prevalence of ICI-induced endocrinopathies in Indian populations remain limited. A study was conducted with an aim to determine the prevalence and spectrum of endocrinopathies resulting from ICI therapy in cancer patients at a tertiary care centre. Methods: This prospective cohort study included 100 adult cancer patients initiated on ICI therapy (anti-PD1 or PD-L1). Patients with pre-existing endocrinopathies or those diagnosed during baseline assessment were excluded. Comprehensive clinical, biochemical, and hormonal assessments were performed at baseline and during follow-up at 1, 2, 3, 6, 9, and 12 months. Endocrinopathies were diagnosed per standard criteria. Associations with demographic and clinical variables were analysed using Fisher's exact test. Results: Endocrinopathies developed in 19% of participants during 12 months of follow-up. Primary hypothyroidism was most frequent (12%), followed by hypergonadotropic hypogonadism (3%), diabetes mellitus (2%), primary adrenal insufficiency (1%), and primary hyperparathyroidism (1%). The median age of those affected was 52.6 years, with a male predominance. Endocrinopathies occurred more commonly with PD-1 inhibitors compared to PD-L1 inhibitors. Hypertension was significantly associated with endocrinopathy development ( Conclusion: ICI-induced endocrinopathies are prevalent among Indian cancer patients, with primary hypothyroidism being the most common. Early onset irAEs underscore the need for regular endocrine monitoring during and after ICI therapy.