A Comparative Study of Treatment Toxicities Between FOLFOX 4 and Modified FOLFOX 6 in Iranian Colorectal Cancer Patients

Background: Colorectal cancer is one major health problem and cancer-related cause of death in cancer patients in countries such as Iran where the most cases are diagnosed in advanced stages. Objectives: To evaluate the incidence and severity of toxic effects in colorectal cancer patients who have been treated with two different schedules of combination of oxaliplatin and bolus/infusional 5-fluorouracil with leucovorin (FOLFOX) and to compare them. Methods: Medical records of 458 patients with colorectal cancer treated with FOLFOX 4 and modified FOLFOX 6 regimen between 2005 and 2014 were reviewed. Data from 96 eligible patients were analyzed. Fifty-six patients (58.3%) received FOLFOX 4 and 40 patients (41.7%) received modified FOLFOX 6. Results: The study included 96 patients, 39 of whom were males (40.6%) and 57 of whom were females (59.4%). The median age was 62 years (range: 38 - 87 years). The follow up duration was between 16 - 109 months with a median of 62 months. There was a statistically significant incidence rate of grade ≥ 1 toxicity of diarrhea as gastrointestinal (GI) toxicity between FOLFOX 4 and modified FOLFOX 6 as the two regimens (P = 0.034), but there was not a statistically significant incidence rate of grade ≥ 1 toxicity of stomatitis as GI toxicity between the two regimens (P = 0.27). We observed a highly statistically significant incidence rate of grade ≥ 1 toxicity of neutropenia as hematologic toxicity between FOLFOX 4 and modified FOLFOX 6 as the two regimens (P < 0.001), but we did not observe any statistically significant differences of grade ≥ 1 of thrombocytopenia as hematologic toxicity between the two regimens (P = 0.063). There was a statistically significant incidence rate of grade ≥ 1 neurotoxicity between FOLFOX 4 and modified FOLFOX 6 as the two regimens (P = 0.017). Conclusions: We showed that in colorectal cancer patients treated with modified FOLFOX6. Some of hematological and non-hematological complications were more than FOLFOX4 and they can be concerned.