Criosurgery with liquid nitrogen versus trichloroacetic acid, or its association, in the treatment of anogenital warts on the penis: a randomized controlled trial

• Grant number: 20/01455-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2020
• End date: December 31, 2021
• Field of knowledge: Health Sciences - Medicine - Surgery
• Principal Investigator: Hélio Amante Miot
• Grantee: Mariana Mathias Morita
• Host Institution: Faculdade de Medicina (FMB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Anogenital warts (AGWs) are prevalent benign epithelial lesions: it is estimated that 10% of individuals will show anogenital warts throughout their lives and that the incidence is between 160 and 289 cases per 100,000 individuals per year, worldwide. Thus constituting major public health problem. They are caused by the human papilloma virus (HPV), especially HPV-6 and 11 types. Despite the implementation of the current vaccination campaign, individuals are still susceptible to AGWs caused by viral types not contained in the vaccine, which justifies its high incidence rate. Currently, there are many topical or ablative therapeutic options available to be used in the treatment of AGWs, however, there are no studies that indicate absolute therapy, since these procedures are associated with limited efficiency and high recurrence rates. In clinical practice, trichloroacetic acid (TCA) and liquid nitrogen (LN) have been used in association by dermatologists and gynecologists, however, there is a lack of clinical trials that compare the association of LN and TCA in the treatment of AGWs and prove the effectiveness of these practices, which enhances the importance of studying this therapeutic approach. Objective: To comparatively analyze the efficacy of the three local destructive strategies for the AGWs of the penis: cryosurgery with liquid nitrogen for 10 seconds, 90% trichloroacetic acid or the combination of both. Method: Randomized, parallel, controlled trial involving men attended at an STD outpatient clinic at the Faculdade de Medicina de Botucatu - UNESP with anogenital warts (AGWs) of the penis. After being randomized, patients who accept to participate in the study will be treated with one of three possible treatments: cryosurgery with liquid nitrogen (LN), caustic therapy with 90% trichloroacetic acid (TCA) or the combination of both, TCA followed by LN. The main dependent variable will be the AGW count before treatment and after four weeks. Other variables will also be analyzed: age, immunosuppression, smoking, topography (glans, stem, foreskin) and education. The data will be evaluated by intention to treat and the variation in the number of lesions will be evaluated by a generalized mixed effects linear model for counts (negative binomial) and adjusted to the covariates. The sample size will be based on a pre-test with the first 80 patients, which should require the monitoring of 120 treatments.