Endocrine Abstracts

Background: Immune checkpoint inhibitors (ICIs) have revolutionised cancer treatment, but are associated with a range of immune-related adverse events (irAEs). Endocrinopathies are particularly common, ranging from thyroid dysfunction to life-threatening adrenal insufficiency due to hypophysitis.

Objective: We performed a retrospective audit to evaluate the incidence, management, and monitoring of endocrine irAEs in a real-world cohort, assessing current practice against guideline recommendations to create a robust standard operating procedure (SOP).

Methods: A 12-month retrospective audit was conducted on 45 patients receiving ICI therapy (monotherapy, combination immunotherapy, or chemo-immunotherapy). Patient demographics, treatment regimens, and longitudinal biochemical results were analysed to identify the incidence of irAEs and evaluate adherence to screening protocols.

Results: Endocrine irAEs occurred in 28.8% of patients (n = 13). Thyroid dysfunction was the most frequent event, with 10 patients (22%) developing primary hypothyroidism. Severe irAEs included two cases of adrenal insufficiency and one of panhypophysitis requiring hospitalisation. The Endocrinology team was consulted in all cases. Overall, 20 patients received combined ICI therapy. Out of 6 patients receiving combination immunotherapy, 3 patients (50%) developed irAEs. Out of 14 patients who received chemo-immunotherapy, 4 (28.5%) developed irAEs.

Conclusion: This audit demonstrated the significant burden of irAEs, particularly when combination therapy is used, the risk significantly increases. It highlights the need for clinicians to be aware of irAEs, particularly as their use is increasing, and it is likely that the true prevalence is even greater. Collaboration between Oncology and Endocrinology teams is essential to create SOPs to ensure early intervention to avoid life-threatening complications such as adrenal crises and diabetic ketoacidosis. As a result of this audit, we created SOPs for thyroid dysfunction, adrenal insufficiency, hypophysitis and new diabetes, and summarised these into infographs with clear pathways for any clinician to utilise.