Combination chemoradiotherapy with gemcitabine: potential applications.

Gemcitabine (Gemzar) is a novel deoxycitidine drug that has demonstrated promising single-agent activity in non-small-cell lung cancer and has been proven to be a potent radiosensitizer. Although the exact mechanism of the radiosensitizing effect is unknown, several studies have focused on the drug's effect on deoxyadenosine triphosphate (dATP) pool depletion or cell-cycle manipulation. A number of trials have evaluated this feature of gemcitabine by combining chemotherapy and radiation in various doses and schedules, and those studies are described in this article. Gemcitabine appears to be a promising agent to be combined with radiation therapy. However, further clinical trials are needed to define optimal doses, toxicity, and efficacy.