Cervical human papillomavirus screening by PCR: advantages of targeting the E6/E7 region

PCR is a promising method for detection of human papillomavirus (HPV), the high-risk forms of which are responsible for cervical cancer. PCR primers that target the L1 or E1 region can be unreliable and may miss more advanced disease, whereas those directed at the E6 or E7 regions, which encode oncogenic products, are preferable because 1) the L1/E1 regions, but never the E6/E7 regions, are lost during integration of viral DNA into host genomic DNA, a process that can represent an integral component of progression from infection to tumorigenesis; and 2) the E6/ E7 nucleotide sequence exhibits less nucleotide variation. The choice of region used for PCR has implications for HPV screening strategies in the clinical diagnosis and management of cervical cancer.