Pathologic fractures of the humerus during adjuvant pembrolizumab in patients with renal cell carcinoma after radical nephrectomy: A case report

Introduction and importance: Immune checkpoint inhibitors (ICIs) have noticeably enhanced oncologic outcomes associated with patient survival in different subtypes of metastatic cancer by enhancing cytotoxic T-cell activity. ICI-associated toxicities are often referred to as immune-related adverse events (irAEs) and occur in nearly every organ system. However, the effect of ICIs on the skeleton is poorly examined, and only a few case series have been published. Case presentation: A 37-year-old man who presented with pathologic fractures of the right proximal humerus during adjuvant pembrolizumab therapy following laparoscopic radical nephrectomy for right renal cell carcinoma. Clinical discussion: ICIs are associated with various irAEs virtually affecting all host tissues, most of which have been described well by pharmacovigilance analyses. However, to date, very few studies have examined the effects of ICI on the skeleton. Conclusion: Urologic oncologists and urologists should be aware of the rare but potentially fatal bone side effects of ICIs.