Immune Checkpoint Inhibitors-Induced Endocrinopathies: Assessment, Management and Monitoring in a Comprehensive Cancer Centre.

OBJECTIVES: To determine the incidence, presentation, frequency and management of immune checkpoint inhibitors (ICI)-related endocrinopathies in a comprehensive cancer centre in Oman, particularly with programme death 1/programme death-ligand 1 (PD-1/PD-L1) inhibitors.

BACKGROUND: A high number of patients treated with PD-1/PD-L1 inhibitors for the management of solid tumours developed endocrinopathies.

METHODS: This is a retrospective study of patients admitted to Sultan Qaboos Comprehensive Cancer Care and Research Centre (SQCCCRC) from August 2021 to December 2022. All adults diagnosed with solid cancers and have received at least one dose of ICIs were included. Patients with incomplete data were excluded from the analysis. Data regarding the ICI-induced endocrinopathy were collected.

RESULTS: A total of 139 patients were included in the study of which 58% were females. The median age of the cohort was 56 years. The incidence of endocrine-related adverse events was 28%. The mean time for the development of endocrine adverse events after treatment initiation was 4.1 ± 2.8 months. Of the patients who developed toxicity, 90% had hypothyroidism. Ten patients developed hyperthyroidism, two patients were diagnosed with secondary adrenal insufficiency/hypophysitis and one patient developed Type 1 diabetes mellitus (DM). Using univariable logistic regression weight and body mass index (BMI) significantly impacted the development of endocrine immune-related adverse events (irAEs).

CONCLUSIONS: This is the first study from the Sultanate of Oman to assess PD-1/PDL-1 ICI-induced endocrinopathies. The most common endocrine adverse event is thyroid dysfunction, mainly hypothyroidism followed by hyperthyroidism. Hypophysitis, primary adrenal insufficiency and CIADM occur less frequently, but have a more significant effect on the patient's health. The treating physician should be aware of ICI-induced endocrinopathies, screening and treatment. Furthermore, our study showed that patients with a higher BMI have a greater risk of developing irAES. Further studies are needed to establish the predictors of endocrine irAEs.