HPV in upper aerodigestive tract tumors in southern Brazil.

Abstract

e15083 Background: The highest rates of esophageal cancer in Brazil occur in Rio Grande do Sul (18/100,000/year for men), where squamous cell carcinoma is the most common. Furthermore, the incidence of head and neck squamous cell carcinoma (HNSCC) is significant in this region (11/100,000/year for cancer of the oral cavity and 10/100,000/year for laryngeal cancer in men). Tobacco smoking and alcohol consumption are the major risk factors for esophageal squamous cell carcinoma (ESCC) and HNSCC. The role of HPV in the development of ESCC remains controversial. Otherwise, there is some evidence that HPV-related HNSCC is a distinct entity compared with HNSCC associated with smoking and alcohol consumption. Methods: Polymerase chain reaction (PCR) was used to evaluate the presence of HPV from 218 samples from three groups of patients. Group 1 comprised 51 patients with ESCC who underwent esophagectomy, in which two samples from each patient were analyzed: one tumor sample and another from normal esophageal mucosa. Group 2 comprised 37 patients with HNSCC who underwent Lugol chromoendoscopy. In this group, we took biopsies from the primary tumor and from esophageal mucosa (unstained areas and middle esophagus when the esophageal mucosa was evenly stained). Thirty-seven dyspeptic patients, non-smokers and without alcohol consumption who underwent endoscopy, comprised Group 3, in which we took one biopsy from middle esophagus. All samples were fixed in formalin and stored in paraffin blocks. Nested-PCR with MY09/11 and GP5/6 primers was used to detect HPV L1 in those samples. Results: Of a total of 224 samples fixed in formalin and stored in paraffin, only 6 samples had insufficient material for PCR analysis: one sample from normal distal epithelium in Group 1, one sample from a stained area and 2 samples from unstained areas in Group 2 and 2 samples from normal esophageal mucosa in Group 3. PCR was positive for one of conserved genes GAPDH, G3PDH or B-globin in 218 samples, showing that DNA was adequate for analysis. The PCR results were negative for HPV DNA in all esophageal samples, as well as in all biopsies from the primary tumor of HNSCC. Conclusions: There is no evidence that HPV is involved in carcinogenesis of the upper aerodigestive tract in southern Brazil.