Endocrine Abstracts

Introduction: Ongoing advancements in the treatment of malignancy has witnessed an increasing use in new immunotherapies, including immune checkpoint inhibitors. Immune-related endocrinopathies affect around 10% of patients treated with checkpoint inhibitors. Common endocrinopathies include thyroid disease and hypophysitis.

Aim: Baseline monitoring test for endocrine disorder in patients started on immunotherapy for cancer treatment and implementation of new trust guidelines to help aid this.

Method: Retrospective single-centre study looking at baseline test for monitoring of endocrine disorders in patients started on immunotherapy for cancer treatment. 22 patients were identified at Queen’s Hospital, London, UK (BHRUT–Barking, Havering and Redbridge University Hospitals NHS Trust) in 2023. Measuring baseline cortisol levels, Thyroid Function Tests (TFTs) and HbA1c monitoring before starting immunotherapy.

Results: 22 patients identified on immunotherapies including Anti-PD-1 Pembrolizumab (11 patients) and anti-PD-L-1 such as Atezolizumab (7patients) and Durvalumab (4 patients). Patients on Pembrolizumab had 55% baseline cortisol, 73% baseline TFTs and 18% baseline HbA1c. Patients on Atezolizumab had 71% baseline cortisol, 29% baseline TFTs and 14% baseline HbA1c. Patients on Durvalumab had 50% baseline cortisol, TFTs and HbA1c checked. Our team presented findings in a departmental teaching and developed local trust guidelines to help aid recommended endocrine test monitoring and recommended advice/action.

Discussion: Immune checkpoint inhibitors use in cancer treatment has increased. Some studies have shown incidence of severe events is reported as 26% for monotherapy and 55% with combination therapy. PD-1 inhibitors are commonly associated with thyroid abnormalities (5-10%) and can occur 4-10 weeks after initiation of treatment. Diabetes Mellitus (DM) incidence of 1% including new-onset type 1 DM or worsening type 2 DM. CTLA-4 inhibitors are commonly associated with hypophysitis (3-6%) and usually present in 8-10weeks of initiation of treatment. Some studies have reported pituitary hormone deficiencies such as secondary adrenal deficiency (83%), secondary hypothyroidism (77%) and hypogonadotrophic hypogonadism (53%). Primary adrenal insufficiency incidence of 1% as monotherapy and 7% in combination therapy. If undiagnosed early these endocrinopathies can be life threatening.

Conclusion: Our study showed more patient and clinician information on awareness of endocrinopathy complications induced by immunotherapy treatment is important. If undiagnosed early these endocrinopathies can be life threatening. It is important to send baseline endocrine testing and monitoring to aid early diagnosis and treatment of complications. There are no national guidelines; our team have developed local trust guidelines for baseline endocrine test monitoring for patients on immunotherapy treatment. We plan to repeat our study in 6months time with a larger sample size.