Glenny, A. M., Fernandez Mauleffinch, L. M., Pavitt, S., & Walsh, T. (2009). Interventions for the prevention and treatment of herpes simplex virus in patients being treated for cancer. Cochrane Database of Systematic Reviews, 1, CD006706.

To examine the effects of interventions for the prevention, treatment, or both, of herpes simplex virus (HSV) in patients receiving treatment for cancer.

• Databases searched were Cochrane Oral Health Group’s Trials Register, CENTRAL, MEDLINE, EMBASE, CINAHL, CANCERLIT, SIGLE, and LILACS.
• Keywords searched were neoplasm, cancer, bone marrow transplant, herpes simplex or herpes labialis, and mucositis herpetic.
• All randomized, controlled trials (RCTs) compared interventions for the prevention or treatment or both of HSV infection in people being treated for cancer.  Published and unpublished studies were included in the searches.
• Articles were excluded if they were not RCTs, did not involve patients with cancer, and did not meet the inclusion criteria.

Forty studies were initially reviewed.

• After excluding studies due to the exclusion criteria, 17 studies remained for analysis.
• The sample size across studies ranged from 21 to 151.
• The majority of studies were conducted in patients with hematologic malignancies.  Only one study included patients with solid tumors.

• Acyclovir was more effective than placebo in the prevention of herpes infections whether given orally (relative risk [RR] = 0.11; 95% CI [0.05, 0.24]) or intravenously (IV) (RR = 0.24; 95% CI [0.07, 0.86]). No differences were found in effectiveness between oral or IV use or between adults and children.
• Valaciclovir appeared to be as effective as acyclovir in two relatively small trials for prophylaxis. In one trial comparing prostaglandin E to placebo, placebo was more effective in prevention than prostaglandin. In terms of herpes treatment, there were only two studies found and reported. Acyclovir was more effective than placebo in terms of time to healing (p = 0.01) and the duration of viral shedding was lower with acyclovir (p = 0.00008) compared to placebo.

The evidence suggested that acyclovir may be beneficial for the prevention and treatment of herpes infection in this patient population; however, the risk ratios were relatively small, suggesting limited benefit.  Valaciclovir may also be effective; however, few studies have reported this particular agent, so firm conclusions cannot be drawn. Prostaglandin E appears to have no benefit for the prevention of herpes infection in this group of patients. The degree of immunocompromised patients in study samples was not discussed, and sample sizes varied across studies, suggesting limited ability to truly generalize the findings provided here.  Acyclovir was more effective than placebo in the prevention of herpes infections whether given orally (RR = 0.11; 95% CI [0.05, 0.24]) or IV (RR = 0.24; 95% CI [0.07, 0.86]). No differences were found in effectiveness between oral or IV use or between adults and children. Valaciclovir appeared to be as effective as aciclovir in two relatively small trials for prophylaxis.

Fifteen trials evaluated the effect for prevention of herpes infection, and two trials evaluated herpes treatment.