Papers of the Week

Data on the diagnosis, natural course and management of immune checkpoint inhibitor (ICI) related hypophysitis (irH) are limited. We propose this study to validate the diagnostic criteria, describe characteristics and hormonal recovery and investigate factors associated with occurrence and recovery of irH. A retrospective study including patients with suspected irH at the University of Texas MD Anderson Cancer Center from 5/2003 to 8/2017 was conducted. IrH was defined as: (1) ACTH or TSH deficiency plus MRI changes or (2) ACTH and TSH deficiencies plus headache/fatigue in the absence of MRI findings. We found that of 83 patients followed for a median of 1.75 years (range 0.6-3), the proposed criteria used at initial evaluation accurately identified 61/62 (98%) irH cases. In the irH group (n=62), the most common presentation were headache (60%), fatigue (66%), central hypothyroidism (94%), central adrenal insufficiency (69%) and MRI changes (77%). Compared with non-Ipilimumab (Ipi) regimens, Ipi has a stronger association with irH occurrence (p=0.004) and a shorter time to irH development (p<0.01). Thyroid, gonadal and adrenal axis recovery occurred in 24%, 58% and 0% patients, respectively. High dose steroids (HDS) or ICI discontinuation were not associated with hormonal recovery. In the non-irH group (n=19), one patient had isolated central hypothyroidism and 6 had isolated central adrenal insufficiency. All remained on hormone therapy at last follow up. We propose a strict definition of irH that identifies the vast majority of patients. HDS and ICI discontinuation is not always beneficial. Long term follow up to assess recovery is needed.