Endocrine Abstracts

The introduction of immune checkpoint inhibitors (ICIs) in clinical management of cancer has had an undeniable impact in management of cancer patients. Currently there are several ICIs are used across Europe including but not limited to, pembrolizumab, atezolizumab, and ipilimumab. Even though their clinical efficacy is reputable, they have the potential of causing serious immunotherapy-related adverse events’ (irADRs) in several organ systems including endocrine organs. With the ever-growing use of ICIs, case reports are emerging with increasing frequency of rare yet life-threatening endocrine dysfunctions, particularly involving the pituitary, thyroid and less frequently adrenals.

Case presentations: Case 1)A 64 y/o patient was admitted under medical team with features of adrenal insufficiency. He had background of metastatic poorly differentiated adenocarcinoma of lung(T4N3M1c), for which he was treated with pembrolizumab (from October 2019 – May 2020), cisplatin, premetrexed, simvastatin 20 mg OD, ezetimibe 10 mg OD and analgesia. She presented with general fatigue, loss of appetite and mouth ulcers since ICI therapy. He was given iv hydrocortisone and the patient improved clinically. On physical examination, the patient’s looked tired and his HR was 116 bpm. Blood test showed his cortisol to be 8 nmol/l, TSH: 4.39 mU/L. He was discharged on prednisolone 10 mg OD which was reduced to 7.5 mg. 2)A 59 years with a background of right eye choroidal melanoma for which she underwent primary enucleation in January 2019 and was subsequently started on Pembrolozumab. She also has other comorbidities like T2DM, HTN, IHD for which she is being medically managed. She was admitted with general fatigue, vomiting and she was hypotensive and her lab findings showed her cortisol to be very low at 28 nmol/l. She was also in in fast AF and AKI. The oncology team reviewed her, and she was started on IV methyl prednisolone and IV fluids following which her AKI resolved. She was discharged on hydrocortisone 10 mg BD.

Discussion/conclusion: Adrenal insufficiency (AI) is a rare irADRs of ICI therapy. If left untreated AI is life-threatening and unlike other autoimmune complication of ICI use AI is irreversible with patients often require long term steroid therapy. Baseline endocrinology tests like TFT, glucose(HbA1C), cortisol need to be done at initiation of treatment and monitored regularly. Based on our findings from this case we believe that it is important that the patients are educated regarding risk of AI and follow up monitoring for signs of AI be put in place post therapy with ICI.