Dose intensity of chemotherapy with cyclophosphamide, methotrexate and 5-fluorouracil in the elderly with advanced breast cancer.

Toxicity and results of two different dose levels of chemotherapy with cyclophosphamide, methotrexate and 5-fluorouracil (CMF) in older (greater than 70 years) patients with advanced breast cancer were evaluated in a prospective (non-randomised) study. During the first three courses of chemotherapy dose reduction for haematological toxicity was necessary in all of 10 and 8 of 13 patients treated with an intended dose of 100% and 75% of standard dose CMF, respectively. The median percentages of CMF, administered during the first three courses were about 75% in both groups of patients corresponding with a median dose intensity of 72% (range 49-87%) and 64% (range 36-78%) for patients of the 100% and 75% dose group, respectively. In 34 younger postmenopausal women (mean age 57 years) treated in our institution for advanced breast cancer the median percentages of CMF in the second and third course were 86% and 84%, respectively with a median dose intensity during the three courses of 82%. Dose reductions of CMF and bone marrow toxicity, though interdependent, were statistically significantly correlated with the endogenous creatinine clearance, but not with age. 1 patient died during severe leukopenia and thrombocytopenia. Non-haematological side effects were most pronounced in the 100% group. Results of therapy in both groups of patients were about equal and compared well with those of CMF therapy in general. It is advised that the dose of CMF in patients above 70 years should not exceed 75% of standard dose. Further dose reduction of methotrexate in case of severe renal failure is required.