Use of metronidazole gel to control malodor in advanced and recurrent breast cancer.

Intolerable malodor emanating from ulcerated tumors as a result of anaerobic infection is a serious problem in the management of advanced and recurrent breast cancer. Metronidazole can control this malodor, but its oral use may cause adverse reactions. We therefore formulated a metronidazole gel, since no equivalent preparation is commercially available in Japan, and used it in five female patients (four with advanced cancer and one with recurrent cancer) admitted to our hospital between March 1994 and July 1995. The patients were aged between 47 and 71 (median: 59) years, and the duration of morbidity in the four patients with advanced cancer ranged from 10 months to four years. In three patients, the tumors were larger than 10 cm x 10 cm. Metronidazole gel was applied to the surface of ulcerated tumors once or twice daily. Independent assessments by the patient, doctor and nurse were unanimous, and revealed that the malodor was alleviated in one patient after three days, and removed in four patients after two to five (median: four) days of metronidazole gel treatment. Culture of swabs showed a decrease or disappearance of anaerobic colonies. Adverse reactions characteristic of metronidazole did not occur. The topical use of metronidazole in a gel form will improve the quality of life for patients with malodorous ulcerated tumors and facilitate intensive treatment of the underlying disease.