Irinotecan-induced Neutropenia: A Comprehensive Review of Pathogenesis, Risk Factors, and Management

Irinotecan is a camptothecin derivative that exerts its antitumor effects by metabolizing into the active metabolite 7-ethyl-10-hydroxycamptothecin (SN-38). It is widely used clinically for treating various advanced solid tumors. However, irinotecan frequently induces neutropenia, predisposing patients to infection and even death. This review aims to provide a theoretical basis for the clinical management of irinotecan-induced neutropenia (IIN). Irinotecan and SN-38 mainly induce hematopoietic stem cell damage and dysfunction by inhibiting topoisomerase I and triggering mitochondrial injury, which ultimately results in neutropenia. Notably, the risk factors of IIN include irinotecan dosage, gene polymorphism, individual baseline characteristics, and drug combination. And several strategies effectively prevent IIN, such as adjustment of drug dosage, genotype testing, oral alkalinizing drugs, supplement of granulocyte colony-stimulating factor, and regulation of intestinal microorganisms. In summary, this review systematically elaborates on the classification, epidemiology, pathogenesis, risk factors, and management strategies of IIN, with the goal of providing references for the clinical prevention and management of irinotecan-related adverse reactions.