Persistentinfection with human papillomavirus (HPV) is the cause of cervical cancer andits precursor cervical intraepithelial neoplasia (CIN). The presence of HPV hasbeen implicated in greater than 99% of cervical cancers, worldwide.
HPV is a small,non-enveloped, double-stranded DNA virus, with a genome of approximately 8000nucleotides. There are more than 118 different types of HPV, and approximately40 different HPVs that can infect the human anogenital mucosa. However, only asubset of 13 to 18 of these types is considered high-risk for the developmentof cervical cancer and its precursor legions.
Althoughpersistent infection with high-risk (HR) HPV is a necessary cause of cervicalcancer and its precursor lesions, a very small percentage of infectionsprogress to these disease states. Sexually transmitted infection with HPV isextremely common, with estimates of up to 75% of all women experiencing HPV atsome point. However, > 90% of infected women will mount an effective immuneresponse and clear the infection in 6 to 24 months without any long-term healthconsequences.
Nucleic acid(DNA) testing by PCR is a non-invasive method for determining the presence of acervical HPV infection. The implementation of HPV DNA testing has increased theefficiency of cervical cancer screening programs by detecting high-risk lesionsearlier in women 30 years and older with NILM cytology and by reducing the needfor unnecessary colposcopy and treatment in patients 21 and older with ASC-US(abnormal) cytology.
