ABSTRACT
Background: Since the introduction of oxaliplatin and irinotecan, they have been the mainstay chemotherapies in the fluorouracil-based regimens, FOLFOX, FOLFIRI, and FOLFOXIRI, used in the treatment of advanced and/or metastatic colorectal cancer (CRC). These regimens are effective and usually well-tolerated in patients. However, they have been associated with neutropenia in some patients. Objective: The aim of this study was to assess risk factors of chemotherapy-induced neutropenia associated with the regimens used in CRC patients. Methods: A retrospective analysis was conducted of all CRC patients’ records who had been treated with the aforementioned regimens between January 2016 and February 2019 at the oncology clinics in a tertiary referral hospital in Riyadh, Saudi Arabia. Results: A total of 136 patients treated with the standard CRC regimens were identified. The majority of CRC patients (63.2%) had stage IV with extensive metastases. Twenty-two patients (16.2%) had developed neutropenia. However, only 13 of the neutropenic patients (59.1%) had shown symptoms of infections or fever. Most neutropenia occurred between the third and the fourth cycle of the used regimen. A significant increase in neutropenia was found in females (p=0.0273) and in patients with stage IV (p=0.0378). However, 53 CRC patients (39.0%) who received filgrastim had shown a significantly lower incidence of neutropenia (p=0.0027). Conclusion: Despite the effectiveness of the CRC chemotherapy regimens, the risk of neutropenia is still considerably elevated. The use of granulocyte colonystimulating factors such as filgrastim is an effective intervention to reduce neutropenia, hence infections, in high-risk CRC patients