HPV infection as a risk factor of esophagus squamous cell carcinoma and it prognosis/A infeccao do HPV como fator de risco para o carcinoma de celulas escamosas de esofago e seu prognostico

Esophageal cancer is the 8th most common cancer in the world, with a survival rate of around 20% in five years. The most common histological type is squamous cell carcinoma, which presents geographical and ethnic variations. The risk factors for this pathology are not well defined. One of the main ones is infection by the Human Papilloma Virus (HPV), which presents frequent but transient conditions, which may regress spontaneously. The subtypes with the highest risk of malignancy are 16 and 18. Thus, a systematic review of the literature was performed based on the reference data, such as Medline, The Cochrane Library, Embase and Lilacs. Articles in languages other than English, Portuguese and Spanish; articles where the full recovery was not possible; those that had missing or insufficient data for evaluation the variables under study; those that focused on the pediatric population, animals and/or cell lines; presence of HPV in extraesophageal locations; benign lesions or malignant neoplasms other than squamous cell carcinoma (SCC); and case reports or case series were excluded. The study analyzed 64 abstracts of articles, 25 of which were included in this review and 39 excluded. The study demonstrated the presence of HPV in the esophageal SCC in 648 (24.4%) of the 2647 neoplastic tissue samples, detected by different techniques. We observed, however, that this great prevalence is very related to the geographic region studied. Finally, it was considered that in fact there is a relationship between HPV and esophageal SCC, as analyzed in the vast majority of studies, but it is not yet possible to reach an effective conclusion about its interference in the patient's prognosis. Keywords: HPV infections; Human Papillomavirus infection; Esophagus cancer; Esophageal neoplasm; Prognostic O cancer de esofago e o 8 mais comum no mundo, com uma taxa de sobrevida em torno de 20% em cinco anos. O tipo histologico mais frequente e o carcinoma de celulas escamosas, o qual apresenta variacoes geograficas e etnicas. Os fatores de riscos para tal patologia nao sao bem definidos. Um dos principais e a infeccao pelo Papiloma Virus Humano (HPV), que apresenta quadros frequentes, porem transitorios, podendo regredir espontaneamente. Os subtipos que apresentam maior risco de malignidade sao o 16 e 18. Dessa forma, uma revisao sistematica da literatura foi realizada a partir da base de dados de referencia, como Medline, The Cochrane Library, Embase, Lilacs. Foram aplicados os cri