Elevated HPV-18 and HPV-16 DNA in the Plasma of Patients with Advanced Cervical Cancer

Every year, more than half a million women develop cervical cancer, half of whom may die eventually (Franceschi, 2005). Several studies have shown the major etiologic role of the human papilloma virus (HPV) infection in neoplasia of cutaneous and mucosal epithelia (Castle et al., 2005; Khan et al., 2005; Kjaer et al., 2006). HPV infection is a common sexually transmitted contamination and both sexes can be infected with the virus. Infection usually clears within a few months and about 90% of the cases became clear within two years of infection (Broomall et al., 2010). However, a small proportion of infections may persist and can progress to cancer in women (Bosch and de, 2002). Of more than 200 types of HPV identified so far, about 35 have shown to be associated with ano-genital neoplasia disorders. Based on such evidence, some HPV types (such as 6, 11, 42, 43 and 44) could be categorized as low risk types, responsible for condyloma acuminate and laryngeal papilloma while some others such as HPV-16 and HPV-18 are considered as high risk viruses, associated with cancers of anogenitalia and cervix (Smith et al., 2007). In accordance with such partitioning, evidence shows the expression of