RESUMO
Currently available therapies are unsatisfactory for locally advanced solid tumors of the lung, head and neck, and brain. Laboratory data suggest that the addition of paclitaxel (Taxol; Bristol-Myers Squibb Oncology, Princeton, NJ), a microtubule-stabilizing drug, to radiation therapy may result in significant radiation sensitization, perhaps because paclitaxel induces cell cycle arrest at G2/M. Relatively low concentrations, 1 to 10 nmol/L, appear to be optimal for direct cytotoxicity and radiosensitization in vitro. Within this dose range, more prolonged exposure seems to result in higher response rates. We are conducting phase I trials designed to test continuous infusion (24 hours per day, 7 days per week) intravenous paclitaxel combined with standard curative-intent radiation therapy. To date, 22 patients are evaluable, and the maximum tolerated dose of paclitaxel has not been reached at up to 2.5 mg/m2/d. Observed toxicities include anemia, lymphopenia, mucositis, and cutaneous erythema/desquamation.