Colonic lung cancer metastasis in vedolizumab-treated immune checkpoint inhibitor colitis

Immune checkpoint inhibitors (ICI) have dramatically improved survival outcomes for multiple malignancies. High-grade, steroid-refractory ICI colitis is a challenging, life-threatening complication that requires urgent hospitalization and treatment. Vedolizumab shows great potential as a gastrointestinal specific treatment option for ICI colitis but its use currently lacks any prospective trial evidence base. This report documents a case of steroid-refractory, pembrolizumab-induced colitis managed with vedolizumab in a male with previously diagnosed stage-IIIb lung adenocarcinoma. The report raises the possibility of an increased risk of colonic metastasis with vedolizumab use and the potential need for closer monitoring and surveillance in patients with a history of active or recent malignancy. Additionally, this case demonstrates the need for consideration of concomitant Cytomegalovirus and Clostridium difficile infection in this patient population. Clear surgical referral and management guidelines must be considered as the increased utilization of ICI continues.