The Results of Chemotherapy with Two Variants of Intravenous CMF in Patients with Early Stage Breast Carcinoma; Does Dose Density Matter?

No direct comparisons can be made in early stages of breast cancer, between the intravenous combinations of: cyclophosphamide, methotrexate, and fluorouracil; named modified versions of CMF with the classical oral version of CMF. Since these modifications have different dose intensities and densities, the outcomes for their subsequent treatments may be varied, and not produce the same results. Despite that, classical CMF has been commonly replaced with intravenous modifications. This study aimed to assess the results of treatment with two common intravenous modification of CMF chemotherapy; to represent the most effective and successful substitute of classical CMF. Five hundred patients in two groups were eligible to take part in the experiment. For two hundred and twenty-nine patients in the group CMF 1&8, chemotherapy was administered intravenously on days 1 and 8 every 28 days for six cycles consisting of: cyclophosphamide 600 mg/m2 , methotrexate 40 mg/m2 , fluorouracil 600 mg/m2 . In the group CMF 1 which consisted of 271 patients, chemotherapy was administered with all the same drugs and doses, however, it was only administered on day 1 and repeated at 21-day intervals for six cycles. Overall survival (OS), disease-free survival (DFS), the prognostic factors and other probable interventional factors were then compared between the two groups. The 5-year OS rate of 87.5% and 10-year OS rate of 82% in the group CMF 1&8 were statistically significantly better than 5-year OS of 84% and 10-year OS of 61.5% in the group CMF 1 (p = 0.01). The 5-year and 10-year DFS rates were 76% and 60% respectively, in the group CMF 1&8 compared with 77% and 54% respectively in the group CMF 1 (p = 0.8). Two groups were comparable regarding their distribution of different prognostic factors and other probable interventional factors. Considering 30% higher dose density of drugs in the protocol of CMF 1&8, the improving outcome can be related to the efficacy of dose-dense chemotherapy. Therefore, this intravenous modification is the better substitute of classical CMF.