Impact of hematopoietic growth factors on the management of small-cell lung cancer.

Hematopoietic growth factors regulate the production and differentiation of immature progenitor cells and activate mature effector cells. With recombinant DNA technology, these human proteins have been biosynthesized, and their clinical applications hold promise for beneficial therapeutic effects. The hematopoietic growth factors are generally classified in 2 groups, the colony-stimulating factors (CSFs) and the interleukins. In oncology, it has been shown that the administration of CSFs will attenuate chemotherapy-induced myelosuppression and permit administration of the planned chemotherapy doses, especially in chemosensitive tumors like small-cell lung cancer. Widespread clinical administration of the CSFs at this time without regard to the predicted risk of a given therapeutic regimen would seem to be inappropriate both therapeutically and economically. Continuing investigations should focus on important clinical end points. Until then, our ability to use the CSFs optimally, rationally, and in a cost-effective manner will remain limited.