Nivolumab-induced immune-related neutropenia in a renal cell carcinoma patient.

INTRODUCTION

Immune checkpoint inhibitors (ICIs) have considerably improved the prognosis of solid tumors. However, this class of medications can cause immune-related adverse events, which represent a distinct spectrum of adverse events in cancer treatment.

CASE REPORT: Here we present a case of immune-related neutropenia (irN) that occurred in a 47-year-old man with metastatic clear cell renal cell carcinoma (ccRCC). During the 18 months of nivolumab monotherapy, severe neutropenia occurred. Buccal mucosal aphthous ulcers and antineutrophil cytoplasmic antibody positivity concurrently emerged with neutropenia. The patient was diagnosed with irN after a comprehensive evaluation ruled out all other likely causes.

MANAGEMENT AND OUTCOME: Neutropenia improved with corticosteroids, but reoccurred with the introduction of nivolumab. During the approximately nine-month follow-up period after nivolumab treatment was permanently discontinued due to neutropenia, there was no disease progression.

DISCUSSION: IrN associated with nivolumab treatment for metastatic ccRCC is uncommon. The pathophysiology of irN is not entirely understood. Corticosteroids are one of the most commonly used drugs for the treatment of irN. As ICIs become more widely used, medical oncologists will encounter this side effect more frequently.