Grimm and Meadows’ evidence-based answer (“Who should have colposcopy?,” J Fam Pract 2003; 52:64–66) raises an important topic, which they presented in Table 1. Hidden within the first line of information in the table are several statements that need to be spelled out and clarified.
The triage of a result of atypical squamous cells of undetermined significance (ASCUS), using data from the Intraepithelial Lesion Triage Study (ALTS) trial,1 is accomplished by 3 medically equivalent methods. As long as there is definite colposcopy/treatment for unresolved lesions at 2 years, all 3 have the exact same rate of detecting cervical intraepithelial neoplasia 2 and 3. The choice of which method to use after an ASCUS result is a joint patient-physician discussion—something family physicians excel at doing.
The discussion that must ensue after an ASCUS smear is whether the woman is less anxious about, feels more comfortable with, and can monetarily afford one method vs. others. For instance, it is immoral to order a human papillomavirus (HPV) test for high-risk types without notifying the patient that HPV is a sexually transmitted infection as well as a cancer marker. Many women have taken legal action against their providers for uninformed and unconsented testing for sexually transmitted infections. Likewise, the woman may not want the results of a sexually transmitted infection put into her medical record. The pros and cons of repeating her Pap smear in 6 months are fairly standard and describe a procedure well-known to women; the pros and cons of undergoing an anxiety provoking examination, such as colposcopy, are not known to most women, but have the benefit of offering an endpoint to the screening/triage tests.
The cost-effectiveness of these 3 methods has been addressed in the Consensus Conferences for the Bethesda System and for the Management of Abnormal Cervical Cytology, as well as in the background work provided to the American Cancer Society for revision of their recommendations for cervical cancer screening. An HPV test for high-risk types is only cost-effective if it is done from a liquid cytology sample and liquid cytology is used for screening every 3 years if they have had 3 prior consecutive normal smears annually.
If the latter half of the prerequisite is not observed in your screening facility, you are expending large amounts of health care money needlessly. Repeating the Pap at 6 months is nearly as cost-effective as doing the HPV test under the above 2 constraints. The largest gains in cost-effectiveness are in lengthening the interval of screening for women with normal findings, not a new triage test.
Liquid cytology can be kept in the laboratory for up to 21 days by Food and Drug Administration approval awaiting an order for HPV testing. Depending on how quickly the cytology is reported to the provider will determine the way in which a follow-up test will be discussed and ordered. If there is sufficient time for the discussion and documentation about which method the woman prefers for follow-up, and if the HPV test is her preferred choice, then she may be able to use the remaining cytology fluid for an HPV test. If the discussion results in the choice of an HPV test after 21 days, she may return for a Dacron swab sampling of her cervix (physician- or self-administered) for the HPV test.
Lastly, it is important for family physicians to realize that 80% of the women who have ASCUS cytology and are positive for high-risk HPV types are completely clear at colposcopy. These women are put into a repeat cytology management plan looking for 2 consecutive, adequate, negative reports at 6-month intervals. If subsequent cytology reports are ASCUS, there is no need for HPV triage, as they must return to colposcopy to resolve the initial ASCUS/HPV positive results. HPV testing should only be used for high-risk types. Testing for low-risk HPV types have nothing to offer the screening or diagnostic procedures for cervical cancer screening.
Diane M. Harper, MD, MPH, Chair, Quality of Life and
Cost Effectiveness Committees for ALTS; Departments of
Community and Family Medicine and Obstetrics &
Gynecology, Dartmouth Medical School, Lebanon, NH.
E-mail: diane.m.harper@dartmouth.edu.
Dr Grimm responds:
I appreciate the clarification offered by Dr Harper on several points.
I agree that the workup of an ASCUS Pap smear needs to be individualized for each patient. Many factors go into deciding between the available options for follow-up of this low-grade cytological abnormality. The ALTS study does demonstrate near equivalence among the 3 strategies cited by Dr Harper. While HPV DNA testing is not a required component of ASCUS follow-up, if high-risk HPV is detected then colposcopy is clearly indicated, as stated in our initial review.