Interventions for prevention and treatment of herpes simplex virus in cancer patients

Relevant data was sourced using the Cochrane Oral Health Group Trials Register, Cochrane Central Register of Controlled Trials, Medline, Embase, CINAHL, CANCERLIT, SIGLE and LILACS. Searching by hand was also carried out, reference lists checked for further trials, and authors and known specialists in the field contacted to try to identify any additional published or unpublished trials.

Randomised controlled trials that concerned treatment or prophylaxis of orofacial lesions [caused by herpes simplex virus (HSV)] in adults, children (or both) who were immunocompromised because of cancer were eligible for inclusion. Outcomes of interest were presence/ absence of clinical/ culture-positive HSV infections (prevention), time to complete healing of lesions (treatment), duration of viral shedding, recurrence of lesions, relief of pain, amount of analgesia, duration of hospital stay, cost of oral care, patient quality of life, and adverse effects. The reports obtained from the electronic and other forms of searches were assessed independently by the review authors. Disagreements were resolved by discussion and reasons recorded.

Authors were contacted for details of randomisation, blindness and sample demographics. Quality assessment was carried out on randomisation, blindness, withdrawals and selective reporting. The Cochrane Collaborations statistical guidelines were followed and risk ratio values were calculated using random effects models.

In the 17 trials, three interventions were studied: use of aciclovir, valaciclovir and prostaglandin E. No trials reported on duration of hospital stay, amount of analgesia or patient quality of life. In the placebo-controlled trials, aciclovir was found to be effective for prevention and treatment. In comparisons of active interventions, there is no evidence of a significant difference in efficacy between valaciclovir and aciclovir, or higher doses of valaciclovir and lower doses. In the single study assessing the effectiveness of prostaglandin E for prevention, this intervention was less effective than placebo. No adverse effects were reported.

There is evidence that aciclovir is effective at preventing and treating HSV infections. There is no evidence that valaciclovir is more efficacious than aciclovir, or that a high dose of valaciclovir is better than a low dose of valaciclovir. There is evidence that, as a prophylaxis, placebo is more efficacious than prostaglandin E. In all included trials the risk of bias was unclear.