Page 73 - Screening for Cervical Cancer: Systematic Evidence Review
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Chapter IV. Discussion
more costly than conventional cytology; only if used in screening intervals of 3 years or longer
will new technologies fall within the traditional range considered to be cost-effective ($50,000
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per life-year).
The Role of HPV Testing in Cervical Cancer Screening and Triage
HPV testing will have the greatest utility if it can aid in identification of those with high-
grade cervical lesions that require prompt treatment and confirm low-risk status among those
with comparatively minor Pap test abnormalities such as ASCUS or cervical intraepithelial
neoplasm (CIN) 1. The performance characteristics of tests for high-risk HPV types suggest
greatest benefit will emerge from the latter role or from combinations with other screening
modalities in the former role to improve detection. The current literature on diagnostic test
performance is of fair quality with good use of histologic tools to verify HPV test results; its
primary limitation is lack of prospective and experimental evidence for its role in screening or
triage.
At least 8 studies evaluating HPV testing in large populations are under way or recently
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completed but not yet in the published literature. The Atypical Squamous Cells of
Undetermined Significance/Low-Grade Squamous Intraepithelial Lesions Triage Study (ALTS)
in the United States has completed enrollment of 5,060 women with ASCUS diagnosed by
conventional cytology and then randomized at enrollment to immediate colposcopy, HPV
testing, or repeat Pap with ThinPrep , the latter two arms are used to triage patients to
colposcopy or less intensive follow-up. Participants are followed for clinical outcomes for two
years from enrollment. The ThinPrep arm was closed before completion of the trial, suggesting
that HPV is at least more effective than repeat cytology using a more sensitive cytology tool.
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