Those of us involved in the healthcare of women have seen a remarkable transformation in screening techniques for cervical cancer and its precursors since the mid 1990s.
•The staid old Pap smear technique of scraping cells from the cervix with a wooden spatula and cotton-tipped applicator and smearing them onto a glass slide is a thing of the past in most practices. We now use plastic collection devices to transfer cells from the cervix into a preservative which is sent to the lab for liquid-based cytology and reflex human papillomavirus (HPV) testing.
•The work of the cytotechnologist is often assisted and in some cases, replaced by electronic screening that employs software-driven intelligence.
•Dysplasia and cervical intraepithelial neoplasia-based terminology gave way to the Bethesda System (TBS) in 1988. TBS has undergone periodic revision, most recently in 2001. We now have atypical glandular cells (AGC) and atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion (ASC-H). Atypical squamous cells of undetermined significance (ASC-US) has been hyphenated.
•In 2002 and 2003, The American Cancer Society and the American College of Obstetricians and Gynecologists moved away from the old dogma of a yearly Pap for every woman starting at age 18 or the onset of intercourse. This empiric regimen has been replaced by data-driven, age-specific screening guidelines.
•The mysteries of the class II Pap have been unraveled, and the National Cancer Institute's Atypical Squamous Cells of Undetermined Significance / Low-grade Squamous Intraepithelial Lesion Triage Study (ALTS) provided data to clarify the role of HPV in ASC-US (the class II Pap's latest incarnation).
•The American Society for Colposcopy and Cervical Pathology (ASCCP) built on the data provided by the many papers generated from ALTS as well as research from around the world, to derive practice guidelines for the management of the abnormal Pap test. These were most recently revised in 2006 based on emerging data.
•The etiology of cervical cancer has been revealed. The disease which epidemiologists had known for decades to result from a sexually transmitted oncogenic agent, has now definitively been shown to be caused by high-risk types of HPV. The discovery led to a Nobel Prize for Harald Zur Hausen in 2008.
•The HPV genome has been largely decoded, and the mechanisms of its ability to cause malignant transformation of host cell lines are becoming understood.
•Adding a test for HPV DNA to the Pap test has been shown to increase the sensitivity and negative predictive value of cervical screening. Furthermore, use of the HPV test has become the mainstay in the triage of an ASC-US cytology result.
•The L1 gene of the HPV has been harnessed to produce a virus-like particle which has, in turn, become the antigenic component of an anti-cancer vaccine. Secondary prevention in the form of Pap testing has given way to primary prevention by vaccination.
We've come a long way!
In this issue of Obstetrics and Gynecology Clinics, an outstanding group of teachers, researchers, and clinicians has come together to discuss all of the above-mentioned and more. In the articles that follow, you will find a review and update in the many aspects of colposcopy and cervical cancer prevention. In addition to reviews of Pap guidelines, and what really happens in the cytology lab, by myself and Dr. Nancy Joste, respectively, the histologic basis of colposcopy is reviewed by Dr. Dennis O'Connor and the controversies surrounding the endocervical curettage are elaborated upon by Drs. Rita Driggers and Chris Zahn. Because our examination of the lower genital tract is not limited to the cervix, an article on colposcopy of the vulva and vagina was contributed by Dr. Hélène Gagné. Several articles are devoted to aspects of the management of the abnormal Pap test and resulting biopsies. These articles incorporate discussion of the 2006 ASCCP Consensus Guidelines and were written by experts, most of whom participated in the Consensus Conference in which they were developed: Drs. Lori Boardman and Colleen Kennedy, Charlie Dunton, Kathy McIntyre-Seltman and Jamie Lesnock, Anna-Barbara Moscicki, and Meggan Zsemlye. Finally, information about the nature of human papillomavirus and the status of the HPV vaccine was contributed by Dr. Cosette Wheeler, one of the world's foremost HPV virologists. Anal neoplasia is also HPV mediated and is on the rise in immunocompromised patients. Drs. Joel Palefsky and Mary Rubin are contributing a discussion of this spectrum of diseases which will appear in the March 2009 issue of this journal.
Cervical cancer prevention is a very dynamic field. It seems that new research on HPV, the management of the abnormal Pap test and the HPV vaccine is being reported almost daily. Much of what worked in 2000 is now obsolete. This issue will bring you up to date as the first decade of the 21st century nears its end, but don't blink - by 2020 today's cutting-edge practices will undoubtedly have been replaced by technologies and practices that we can only begin to imagine.
Professor, Department of Obstetrics and Gynecology, University of New Mexico Health Science Center School of Medicine, MSC10 5580, 1 University of New Mexico, Albuquerque, NM 87131-0001
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