CONCEPTS OF TUMORAL KINETICS APPLIED TO CHEMOTHERAPY OF BREAST CANCER

Abstract

Most patients who have breast cancer are submitted to chemotherapy, and the proven benefits of adjuvant chemotherapy on disease-free and overall survival in breast cancer can be explained through concepts of cell kill. The application of log-kill concepts of Skipper to human breast cancer growth, which seems to follow Gompertzian kinetics, implies not only the use of non-cross-resistant drugs is important, but also the dose and the intensity of chemotherapy are clinically important variables which can be used in order to improve disease free survival and overall survival. This literature review presents certain important theoretical concepts of tumoral kinetics in breast cancer therapy. The chemotherapy is scheduled according to the dose and the compounded agent efficiency; and the dose-intensity concept with increasing of the doses and reduction of the breaks between the cycles aiming the optimization, formulating the high-dose and dose-dense schedules. Norton-Simon hypothesis, which supports sequential therapy might make the administration of cytotoxic agents into dose dense and these schedules would have an advantage on conventional schedules of drug administration which are also discussed.