Herpes infections in breast cancer patients treated with adjuvant chemotherapy

Objective: There is little information on Herpes zoster infection in breast cancer patients as a complication during adjuvant chemotherapy. The aim of this study is to evaluate the incidence of Herpes zoster and simplex infections in this patients setting. Methods: We analyzed 623 early-stage breast cancer patients in our Institute over a period of 7 years (1998-2005). Four-hundred and sixty-onepatients were treated with anthracycline-based chemotherapy, 116 with CMF and 46 with taxane-containing regimens. Results: Twelve (1.9%) developed herpes zoster; 9 patients, receiving anthracycline-based chemotherapy, two taxane-containing regimens, and one CMF regimen. Herpes zoster infection required treatment delay in 6 patients. Adjuvant chemotherapy was delayed for 1 week in 2 patients, while in 4 patients with more severe symptoms chemotherapy was delayed for 2 weeks. One patient, despite i.v. acyclovir, had severe postherpetic motor neuropathy with a permanent ambulation impairment, and chemotherapy was stopped. In our study, herpes zoster occurred in 55/1,000 cases/year. The reported incidence in the general population varies between 2.2 and 4.1 per 1,000 patients/year; therefore, the risk of developing herpes zoster in these patients may be 13- to 25-fold higher compared to the incidence in the general population. In addition, 13 of 623 patients developed herpes simplex. Conclusion: Our findings suggest that adjuvant chemotherapy can facilitate reactivation of herpes infection.