Emergency Presentations of Immune Checkpoint Inhibitor-Related Endocrinopathies

Immune checkpoint inhibitors (ICI) are an important component of anticancer treatment, with indications across an increasing range of oncological diagnoses. ICIs are associated with a range of immune-mediated toxicities. Immune-related endocrinopathies pose a distinct challenge, given the nonspecific symptom profile and potentially life-threatening sequelae if not recognized.

To determine the frequency and clinical presentations of immune-mediated endocrinopathies in patients treated with ICIs presenting as emergencies.

A prospective observational cohort study was undertaken at a specialist oncology hospital in North West England from May 20, 2018 to May 19, 2020. Within the hospital, the Oncology Assessment Unit (OAU) acts as the receiving unit in which assessments are undertaken of all emergency presentations. All patients treated with ICIs presenting to the OAU were included. The primary outcome was diagnosis of an immune-mediated endocrinopathy. Length of inpatient stay, and 7- and 30-day mortality rates were examined.

During the study period, 684 patients treated with ICIs presented to the OAU. Twenty-four (3.5%) patients had an acute immune-mediated endocrinopathy, of which 17 had hypophysitis, 4 diabetes mellitus, 2 thyrotoxicosis, and 1 adrenalitis. Median length of stay for patients with hypophysitis was 1 day. No patient with an immune-mediated endocrinopathy died within 30 days of presentation.

Presentations to emergency settings with acute immune-mediated endocrinopathies are rare. Early recognition of immune-mediated toxicities is important, and particularly pertinent in ICI-related endocrinopathies, where even in life-threatening cases, the presentation can be vague and nonspecific.