Utility of periodic medical questionnaires and examinations for immune-related adverse event screening: A prospective observational study

Background Immune checkpoint inhibitors (ICIs) are associated with immune-related adverse events (irAEs) specific to the immunity-boosting activity of the drugs and may necessitate discontinuation of treatment depending on their severity. IrAEs may be difficult to diagnose in their early stages as they can occur in any organ. The present, prospective, observational study is the first to attempt to assess the utility of periodic medical questionnaires and laboratory, radiological, and physiological examinations in diagnosing irAEs. Methods We analyzed 51 patients who received immunotherapy for metastatic renal or urothelial carcinoma at Tokyo Metropolitan Tama Medical Center between 2016 and 2020. A medical questionnaire consisting of 41 questions and laboratory tests were administered to the patients on the day of each ICI administration and 1 week afterwards. A significant complaint was defined as a complaint not addressed in the questionnaire immediately prior to the first ICI administration. Results Fifty-one patients with metastatic renal or urothelial carcinoma were enrolled. The mean age was 72.1 years (range: 54-88 years). The male: female ratio was 32: 19. Of the total cohort, 26 (51%) patients had renal carcinoma, and 25 (49%) had urothelial carcinoma. The median follow-up time was 2.6 (range: 0.4-40.7) months. Thirty-three patients (65%) experienced irAEs. Conclusions In our cohort, periodic medical questionnaires and examinations were effective for early diagnosis and prompt treatment of irAEs. Although periodic examinations led to a high irAE diagnosis rate, the attendant medical cost was high. Further study is needed to find ways of addressing this issue.