Prevalence and association of human papillomavirus 16, Epstein-Barr virus, herpes simplex virus-1 and cytomegalovirus infection with human esophageal carcinoma: A case-control study

Recent research shows esophageal carcinoma (EC) as the ninth most common malignancy in the world. The association of viral infection and EC has been reported in the last 30 years. However, geographic variation in infection rates and the key mechanisms of the viral action have yet to be resolved. This study aimed to determine the prevalence and association of human papillomavirus 16 (HPV-16), herpes simplex virus 1 (HSV-1), Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infection in the etiology of EC in the area of Shantou, Guangdong, China. Nested PCR was used to detect viral DNA in the mucosa of 70 cases of EC and in paracancerous tissues, as well as 100 cases of normal esophagus mucosa. Data were analyzed by chi(2) test, Fisher's exact test and bivariate correlation analysis. The infection rates of HPV-16, HSV-1 and EBV were 40.0, 30.0 and 30.0%, respectively, in EC mucosa, and were significantly higher than those in normal mucosa. However, no CMV DNA was detected in either EC or normal mucosa. HPV-16 or EBV infection was mainly detected in EC patients 48-58 years old, and the infection rate was positively associated with pathological grade of EC (P < 0.05). Tobacco smoking and alcohol consuption were high risk factors for HPV-16 infection for male patients [odds ratio (OR), 5.9; 95% confidence interval (CI), 1.4-24.6; OR=3.8; 95% CI, 1.1-13.8] Rates of infection with a mixture of these 3 viruses were all more than 10.0% in cancerous mucosa and closely related to the pathological grade of EC (P=0.001). Infection with HPV-16, HSV-1 or EBV may be an important etiological factor in EC.