Antibacterial prophylaxis after chemotherapy for solid tumors and lymphomas.

Background The role of prophylactic antibacterial agents after chemotherapy remains controversial. Methods We conducted a randomized, double-blind, placebo-controlled trial in patients who were receiving cyclic chemotherapy for solid tumors or lymphoma and who were at risk for temporary, severe neutropenia (fewer than 500 neutrophils per cubic millimeter). Patients were randomly assigned to receive either 500 mg of levofloxacin once daily or matching placebo for seven days during the expected neutropenic period. The primary outcome was the incidence of clinically documented febrile episodes (temperature of more than 38°C) attributed to infection. Secondary outcomes included the incidence of all probable infections, severe infections, and hospitalization but did not include a systematic evaluation of antibacterial resistance. Results A total of 1565 patients underwent randomization (784 to placebo and 781 to levofloxacin). The tumors included breast cancer (35.4 percent), lung cancer (22.5 percent), testic...