In the news, low-tech loses to high-tech

 

CAP Today

 

 

 

May 2009
PAP/NGC Programs Review

Ann T. Moriarty, MD

On April 2, the New England Journal of Medicine published a study reporting the success of a cervical cancer screening program in rural India using human papillomavirus testing as a primary test and comparing it to the Papanicolaou test and visual inspection of the cervix with acetic acid.1 There are no widespread screening programs in India and the authors assumed a death rate of 20 cases of cervical cancer per 100,000 women when they designed their trial. HPV testing, using the high risk pooled detection method of Hybrid Capture II, Digene/Qiagen, was successful in detecting cervical cancer patients, and there was a decrease in the number of advanced cervical cancers and death rate in the HPV arm over 15 years of the study. The authors comment that the training and quality assurance requirements for HPV testing were much less than for Pap testing—their “technicians” who screened the conventional Paps used in the Pap test arms were trained for only three months at the Tata Memorial Centre. The drawback cited for the use of HPV testing in India was its high cost; a less expensive test is needed to be practical. In addition, the authors said cervical cancer screening using HPV testing should not begin before age 30 because of the high prevalence of transient HPV infections in the younger age group.

The success of this study is a great step forward in defining a screening program for the women of India. The incidence and death rate of cervical cancer is mind-boggling to Americans who have reaped the benefits of personalized screening programs since the 1950s. Offering a screening test to detect and treat cervical cancer and its precursors, thus lowering the incidence of cervical cancer, is good medicine. Each country must define what is reasonable, given the resources of that country.

Enter the New York Times, in which a commentary “DNA test outperforms Pap smear,” was published on April 7.2 The author opens with the comment that gynecologists hope that HPV testing will replace the Pap test in wealthy countries, as well as “cruder” tests in low-resource countries. This is the same publication that reported “Pap test, a mainstay against cervical cancer, may be fading“ on Jan. 16, 2007.3

Why is the most successful screening test in medicine so beleaguered? In the United States we are blessed with a relatively low-cost screening test, well-trained cytotechnologists, and a cervical cancer rate that has been vanquished to less than 4,000 deaths per year.4 Apparently in the U.S., high-tech wins over low-tech in the war of journalism and medicine. As in India, the United States needs to base its screening programs on the available resources and consumer expectations. In this era of personalized medicine (and litigated medicine), the risk of missing a single case of cervical cancer is not a risk that anyone wants (or tolerates).

In the United States, we begin screening early using the Pap test, use the HPV test to help manage those women with atypical squamous cells of undetermined significance, or ASC-US, after age 20, and use HPV tests in conjunction with a Pap test to identify those women over 30 years of age who are at low risk for cervical cancer so that the interval for screening can be lengthened.5 These guidelines are consensus driven, based on the best available scientific data. While one can argue that the role of Pap testing may change in the United States, it will, it is hoped, be based on the appropriate use of tests in a country with established, successful, cervical cancer screening practices. Casting doubt at this time on the legitimacy of Pap test screening in the United States only thwarts efforts to detect cervical cancer. Women in the U.S. should have regular Pap tests with appropriate adjunctive tests as dictated by their clinical risk factors, age, and screening history.

CAP president Jared Schwartz, MD, PhD, responded to the New York Times on behalf of the CAP (see The following was sent to the New York Times). What works for rural India cannot be recommended responsibly for the United States. If women in this country lose faith in the low-tech Pap test, insisting on the HPV test instead, there is risk that women will be over-treated and of possible harm. “Low” sustaining technology with long-term proven efficacy is preferable to misapplying high-tech testing when cervical cancer is the target.

Reference

  1. Sankaranarayanan R, Nene BM, Shastri SS, et al. HPV screening for cervical cancer in rural India. NEJM. 2009;360:1385–1394.
  2. McNeil D. DNA test outperforms Pap smear. New York Times, April 7, 2009.
  3. Pollack A. Pap test, a mainstay against cervical cancer, may be fading. New York Times, Jan. 16, 2007.
  4. American Cancer Society. Cancer Facts & Figures 2008. Atlanta: American Cancer Society; 2008.
  5. Wright TC, Massad LS, Dunton CJ, et al. 2006 consensus guidelines for the management of women with abnormal cervical cancer screening tests. Am J Obstet Gynecol. 2007;197:346–358.

Dr. Moriarty, vice chair of the CAP Cytopathology Committee, is a senior pathologist at Ameripath Indiana, Indianapolis.
 

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