Type-specific detection of human papillomaviruses in Kazakh esophageal squamous cell carcinoma by genotyping both E6 and L1 genes with MALDI-TOF mass spectrometry

Background: Many studies have suggested a relationship between human papillomavirus (HPV) infection and the risk of esophageal squamous cell carcinoma (ESCC). However, findings are inconclusive, potentially because of geographic heterogeneity and variations in detection methods. Objectives: We sought to further investigate the prevalence of HPV with a new detection method, the MassARRAY Sequenom technique, in esophageal squamous cell carcinomas occurring in patients belonging to Kazakh populations in Xinjiang, China. Study design: In the present study, a novel genotyping method for detecting 30 HPV genotypes, specifically by genotyping both the HPV E6 and L1 genes with multiplex PCR using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) (PCR-MS) was first adopted to evaluate HPV genotypes in 89 esophageal cancer samples and 49 matched adjacent normal esophageal tissues. Results: Six HPV genotypes (HPV6, HPV16, HPV33, HPV39, HPV51, and HPV82) were present in at least 51.7% of the esophageal carcinoma tissues, which was significantly greater than 28.6% prevalence among controls (P < 0.05). HPV16 was the most common of all the genotypes investigated (HPV16 prevalence in carcinoma tissue: 49.4%; odds ratio 3.02, 95% confidence interval 1.39-6.53). HPV-positive ESCC patients were generally younger than HPV-negative patients (P = 0.04). In addition, HPV infection was more common in cases of well-differentiated and shallower invasive depth. Conclusions: Based on this new detection method, our findings reiterate the possibility that HPV infection (especially HPV16) may be involved in the etiology of esophageal carcinoma in the Kazakh populations and that HPV E6 gene positivity may be associated with prognosis of patients.