As virtually all cervical cancers are thought to result from human papillomavirus (HPV) infection, it would be reasonable to consider testing for HPV DNA as a screening test for cervical cancer. There are problems with HPV DNA testing, however, as a primary screening test (a use for which the test is not FDA approved). The first is to find a feasible test that detects the optimal number of types of HPV. The currently marketed Hybrid Capture 2 (HC2) test detects the presence of 13 types of HPV that have been associated with cervical cancer. The sensitivity of this test for detecting cervical intraepithelial neoplasia (CIN) 2-3 is about 84%.[1] Further refinements in the test could increase sensitivity.

A second problem with using HPV DNA testing for primary screening is that many women have transient HPV infection that is asymptomatic and of little clinical consequence. Thus, detecting such women would potentially increase unnecessarily the number of follow-up diagnostic workups. This low specificity of HPV testing is most problematic in younger women, who have the highest prevalence of these inconsequential infections.

The ASCUS/LSIL Triage Study (ALTS) found that HPV testing was most useful in triaging women with the ambiguous atypical squamous cells of undetermined significance (ASCUS) findings on cytologic screening. This trial randomly assigned women with ASCUS to one of three evaluation strategies: immediate colposcopy; triage-to-colposcopy based on HPV results from HC2 testing; and conservative management. The HPV-triage strategy detected about as many cases of CIN 2+ as the immediate-colposcopy strategy, but only 56% of women underwent colposcopy. Thus, the study concluded that HPV testing of the large number of women with ASCUS findings for triage to colposcopy is a more efficient strategy than immediate colposcopy. This strategy was also more efficient than conservative repeat-cytologic testing.[2]

References:

1. Hartmann KE, Hall SA, Nanda K, et al.: Screening for Cervical Cancer. Rockville, Md: Agency for Health Research and Quality, 2002. Available online. Last accessed February 20, 2007.
2. Solomon D, Schiffman M, Tarone R, et al.: Comparison of three management strategies for patients with atypical squamous cells of undetermined significance: baseline results from a randomized trial. J Natl Cancer Inst 93 (4): 293-9, 2001.