hematologic toxicities in colorectal cancer patients who received folfox4

background: over the past decade, survival from advanced colorectal cancer is increasing. therefore patients have more exposure to chemotherapy and related toxicities. this study determines how hematologic toxicity patterns affect therapy and care. methods: from april 2010 to march 2013, we enrolled 127 patients with stages iib to iv colorectal cancer. patients underwent complete blood count monitoring prior to and during each cycle of folfox4 chemotherapy. granulocyte colony stimulating factor was injected if their white blood cells were below 3.5×109/l. results: the most common hematologic toxicities were grades 1-2 for hemoglobin (76.83%) and leukopenia (26.48%). the least common hematologic toxicity was thrombocytopenia (4.69%) for all grades of platelet toxicity. the median granulocyte colony stimulating factor injection was 3.33 per 12 cycles. conclusion: anemia and leukopenia are the most common hematologic abnormalities expected with folfox4 chemotherapy regimens for colorectal cancer. the most important factor for predicting hematologic toxicities in patients who receive chemotherapy for colorectal cancer is the number of chemotherapy cycles.