Chemotherapy dose density in early-stage breast cancer and non-Hodgkin's lymphoma

Delivering standard-dose chemotherapy on schedule is important for survival in early-stage breast cancer and non-Hodgkin's lymphoma. Trials of dose-escalated regimens, in which higher-than-standard doses of chemotherapy are used, have produced equivocal results. In contrast, dose-dense regimens, in which standard doses are given with shorter (usually 14-day) intervals between cycles, have been more efficacious than standard 21-day regimens in trials in both early-stage breast cancer and non-Hodgkin's lymphoma. Furthermore, a shorter course of chemotherapy is likely to cause less disruption in patients' lives. Despite the evidence of the importance of maintaining chemotherapy dose intensity (the amount of drug administered/unit of time), undertreatment of patients with early-stage breast cancer and non-Hodgkin's lymphoma is common. Neutropenia is the primary dose-limiting toxicity of many chemotherapy regimens, and it is frequently managed by dose reductions and delays that decrease dose intensity. Colony-stimulating factors reduce the prevalence and severity of neutropenia and its complications, and their proactive use can improve adherence to the planned schedule of both standard-dose and dose-dense chemotherapy. The promising results with dose-dense chemotherapy in early-stage breast cancer and non-Hodgkin's lymphoma indicate that it should be tested in patients with other chemosensitive tumors.