A Mathematical Model of Breast Cancer Treatment with CMF and Doxorubicin

A mathematical model is presented to investigate the ordering phenomenon observed in the comparison of alternating to sequential regimens of CMF (cyclophosphamid, methotrexate, 5-fluorouracil) and doxorubicin used in breast cancer chemo-therapy. The ordinary differential equation model incorporates cell cycle specificity and resistance to study why doses of the same drugs given in different orders result in different clinical outcomes. The model employs a pulsing condition to simulate treatment and induced resistance, and we investigate treatment outcome by simulating a patient population by varying parameters using uniform distributions. The results of these simulations correspond to those observed in prior clinical studies and suggest that drug resistance might be a key mechanism in the sequential regimen's superiority.