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 nonhematological complications were more than folfox4 and they can be concerned.