Human papillomavirus and cervical cancer

Eileen M Burd, Eileen M Burd

Abstract

Of the many types of human papillomavirus (HPV), more than 30 infect the genital tract. The association between certain oncogenic (high-risk) strains of HPV and cervical cancer is well established. Although HPV is essential to the transformation of cervical epithelial cells, it is not sufficient, and a variety of cofactors and molecular events influence whether cervical cancer will develop. Early detection and treatment of precancerous lesions can prevent progression to cervical cancer. Identification of precancerous lesions has been primarily by cytologic screening of cervical cells. Cellular abnormalities, however, may be missed or may not be sufficiently distinct, and a portion of patients with borderline or mildly dyskaryotic cytomorphology will have higher-grade disease identified by subsequent colposcopy and biopsy. Sensitive and specific molecular techniques that detect HPV DNA and distinguish high-risk HPV types from low-risk HPV types have been introduced as an adjunct to cytology. Earlier detection of high-risk HPV types may improve triage, treatment, and follow-up in infected patients. Currently, the clearest role for HPV DNA testing is to improve diagnostic accuracy and limit unnecessary colposcopy in patients with borderline or mildly abnormal cytologic test results.

Figures

FIG. 1.
FIG. 1.
Schematic representation of the circular HPV DNA genome.
FIG. 2.
FIG. 2.
Pathogenesis of oncogenic HPV. HPV E6 and E7 genes encode multifunctional proteins that bind primarily to cellular p53 and pRB proteins, disrupt their functions, and alter cell cycle regulatory pathways, leading to cellular transformation.
FIG. 3.
FIG. 3.
Cervical condyloma showing proliferation of the suprabasal epithelial layers and koilocytic atypia, consisting of nuclear pyknosis and a well-defined perinuclear cavity associated with peripherally thickened cytoplasm. Reprinted with permission of S. Kini.
FIG. 4.
FIG. 4.
ThinPrep Pap Smear showing abnormal squamous cells with HPV cytopathic effect (arrow), consistent with LSIL.

Source: PubMed

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