Chemotherapy dose intensity in non-Hodgkin's lymphoma: is dose intensity an emerging paradigm for better outcomes?

Abstract

Higher chemotherapy dose intensity has been studied as a way of improving the clinical outcomes in various malignancies, including non-Hodgkin's lymphoma (NHL). We reviewed clinical trials that have studied the relation between dose and response in cancer chemotherapy, the theory behind dose-intense chemotherapy, and the clinical results with dose-escalated and dose-dense therapy in aggressive NHL. Myeloablative high-dose chemotherapy with stem cell transplantation produces higher 5-year survival rates than standard salvage chemotherapy in relapsed aggressive lymphoma, but its role as initial therapy is not yet clear. Nonmyeloablative dose-escalated chemotherapy is feasible with granulocyte colony-stimulating factor (G-CSF) support, but this approach does not improve outcomes. Dose-dense (14-day) CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) with G-CSF support produces better results than 21-day CHOP in patients with previously untreated aggressive lymphoma, without additional toxicity. The addition of etoposide to dose-dense CHOP may provide further benefits in younger patients. The addition of rituximab to G-CSF-supported dose-dense CHOP is feasible. Preliminary data suggest the feasibility of dose-dense chemotherapy for NHL with the once-per-cycle G-CSF, pegfilgrastim. Dose-dense chemotherapy with G-CSF support produced better clinical outcomes in both younger and older patients. Phase 3 trials of dose-dense CHOP plus rituximab with CSF support are warranted.