The US-based journal Obstetrics and Gynecology carries a front-page editorial: “Abuses in Human Papillomavirus DNA Testing”. A study featuring in July’s issue based on a survey of nationally representative samples of smear-test (pap test) providers reports widespread overuse of HPV testing in the context of routine smear tests. The editorial dramatically concludes that this “seriously wastes government, payer, and patient dollars, but also potentially harms patients, therefore violating the first tenet of the Hippocratic oath”.
To understand the problem, we need to bear in mind:
i. that only some of the HPV genotypes are associated with cervical carcinogenesis, and that HPV DNA tests have recently become available capable of screening for exclusively “high-risk” strains;
ii. that US national guidelines recommend HPV testing (“reflex testing”) of women with atypical squamous cells of undertermined significance (ASC-US): HPV-positive women are referred to colposcopy and HPV-negative women rescreened in 12 months;
iii. that US national guidelines also recommend HPV testing in the context of a routine three-yearly smear-test (“co-testing”), but only in the case of women aged 30 years and older. (In the younger age-groups occurrences have been shown to be pervasive but transient). Negative cytology and positive HPV – or, conversely, ASC-US cytology and negative HPV – triggers re-screening after a year; ASC-US cytology plus positive HPV warrants referral for colposcopic evaluation. More abnormal cytology (i.e. low-grade intra-epithelial lesions and anything more serious) triggers colposcopic evaluation
This study discovered three areas of widespread “abusive” testing:
1. 28.5% of routine test providers employed HPV DNA tests for “low-risk”, as well as “high-risk strains of HPV. The low-risk HPV test is not recommended in this setting – or, for that matter, in any other health setting – though for some reason the test remains widely available;
2. 60% of health-care providers, and 66% of clinics, used routine HPV co-testing in women aged under 30. This presumably leads to over-testing and unnecessary referrals;
3. health care providers performed reflex testing in cases of intra-epithelial lesions, warranting immediate referral for colposcopy. This might indicate that women were being put at unnecessary risk of cervical cancer.
So why is practice so frequently in breach of current (2006) guidelines? The authors mention amongst possible factors: the availability of low-risk HPV DNA tests, test marketing, health care provider confusion over the difference between high-risk and low-risk tests, financial gain in the form of liberal test reimbursement of private practice by private insurance, patient requests to test HPV status. They point to the need for wide-reaching interventions such as limiting test reimbursement to facilitate recommended uses of HPV DNA tests and eliminate low-risk HPV testing, and education materials for patients and health care providers to address patient demand for HPV testing.
Jennifer Wai-Yin Lee et al., “Low-Risk Human Papillomavirus Testing and Other Nonrecommended Human Papillomavirus Testing Practices Among U.S. Health Care Providers”, Obstetrics and Gynecology, vol. 118, no.1, July 2011
Editorial, Philip E. Castle, “Abuses in Human Papillomavirus DNA Testing”, Obstetrics and Gynecology, vol. 118, no.1 July 2011