The Incidence of Hematological Toxicities in Colorectal Cancer Patients Treated With Fluoropyrimidine-Based Regimens at Princess Noorah Oncology Center.

Background Fluoropyrimidine-based regimens are used for the management of colorectal cancer, which is the second most common cancer in Saudi Arabia. We aimed to study the incidence of hematological toxicities in colorectal cancer patients treated with fluoropyrimidine and fluoropyrimidine-based regimens at Princess Noorah Oncology Center, King Abdulaziz Medical City- Jeddah, Saudi Arabia.  Methods A retrospective cohort study that included adult colorectal cancer patients who were treated with fluoropyrimidine-based regimens from January 1, 2018 to December 31, 2018 at Princess Noorah Oncology Center, Jeddah, Saudi Arabia was performed. Our primary objective was to determine the incidence of anemia, neutropenia, and thrombocytopenia in colorectal cancer patients treated with fluoropyrimidines and fluoropyrimidine-based regimens. Secondary objectives were to assess the grade of hematological toxicities associated with 5-fluorouracil (5-FU) use and to determine the frequency of unplanned hospital admissions or emergency department (ED) visits after receiving fluoropyrimidine-based regimens. The collected data contained patients' characteristics (weight, height, age, gender, and diagnosis), chemotherapy agents, and hematological toxicity-related findings such as absolute neutrophil count, hemoglobin, platelet count, and number of ED visits or hospital admissions during fluoropyrimidine-based chemotherapy regimens. Results Of the 570 cycles of the fluoropyrimidine-based regimen received by 68 patients, hematological toxicities were observed in 508 (89.1%) cycles, and grade ≥ 3 grade toxicities were found in 46 (8.1%) cycles. The results demonstrated a statistically significant difference in the incidence of grade 3-4 neutropenia between patients who received bolus administration of 5-FU and those who did not (8.5% vs. 2.3% respectively, p=0.025). The incidence of grade 3-4 anemia was higher in the bolus group (11.3%) compared to the group where bolus was omitted (4.6%); however, the difference was not statistically significant (p=0.059). Furthermore, there was no significant difference among the two groups for grade 3 and grade 4 thrombocytopenia (0.0% with bolus given and 0.7% with bolus omission p=1.00). Conclusion Our retrospective study showed that there have been significantly higher grade 3-4 hematological toxicities observed with bolus administration of 5-FU, which confirms the previous reports.