HPV Infection and Altered Methylation of Specific Genes in Esophageal Cancer

The global burden of cancer is increasing; this is considered to be largely because of change in life-style, an increasing adoption of cancer-causing behaviors and exposure to carcinogens in the environment. Based on IARC statistics, 12.7 million cancer cases are diagnosed and 7.6 million cancer deaths are estimated world-wide (Ferlay et al., 2008). Esophageal cancer is the sixth most common cause of cancer-related deaths with an estimated incidence of 482,300 new cases and 406,800 deaths every year (Jemal et al., 2011). Etiology of esophageal cancer is not yet clear, but it is a multi-step progressive process. Major risk factors for esophageal cancer are not well-characterized, but may include poor nutritional status, low intake of fruits and vegetables, drinking beverages at high temperatures, tobacco usage and alcohol consumption (Engel et al., 2003; Islami et al., 2009; Wu et al., 2009). Earlier work