Short Communication Mouthwash as a Low-Cost and Safe Specimen Transport Medium for Human Papillomavirus DNA Testing of Cervicovaginal Specimens Philip E. Castle, 1 Mark Sadorra, 2 Francisco A.R. Garcia, 3 Allison P. Cullen, 4 Attila T. Lorincz, 4 Amy L. Mitchell, 3 Denise Whitby, 5 Ronald Chuke, 4 and Janet R. Kornegay 2 1 Division of Cancer Epidemiology, National Cancer Institute, NIH, Department of Health and Human Services, Bethesda, Maryland; 2 Roche Molecular Systems, Alameda, California; 3 University of Arizona Health Sciences Center, Tucson, Arizona; 4 Digene Corporation, Gaithersburg, Maryland; and 5 Science Applications International Corporation-Frederick, Frederick, Maryland Abstract The usefulness of mouthwash as a transport medium for cervical specimens for carcinogenic human papillomavirus (HPV) DNA testing has not been evaluated. Two cervical specimens were collected from each of 34 patients, with one placed in mouthwash (Scope, Proctor and Gamble, Inc.) and the other in a liquid cytology medium commonly used for HPV DNA testing in alternating order. Paired specimens were tested by a PCR assay for carcinogenic HPV and a PCR HPV genotyping assay for 37 HPV types at 0, 3, and 6 weeks after collection; the results of the HPV genotyping assay were categorized into HPV risk groups according to cancer risk (HPV-16 > HPV-18 > other carcinogenic HPV types > noncarcinogenic HPV types > negative). After 4 months of storage, specimens were tested using a second, non-PCR test for carcinogenic HPV. We observed a z94% total agreement and k values of z0.88 between media at each time point for PCR-detected carcinogenic HPV. We observed a z74% total agreement, z0.62 unweighted k , and z0.75 linearly weighted k between media at each time point for PCR-detected HPV cancer risk category. Finally, we observed an 88% total agreement and k of 0.77 between media for carcinogenic HPV detection using a second test after 4 months of storage. We suggest that mouthwash might be used as a low-cost, safe, nonflammable storage and transport medium for cervical specimens for HPV DNA testing in cervical cancer screening programs. (Cancer Epidemiol Biomarkers Prev 2007;16(4):840–3) Introduction Cervical cancer screening using Papanicolaou (Pap) smears or cytology has significantly reduced the incidence and mortality of cervical cancer where effective programs have been instituted (1). However, arguably, cytology has reached its limits in global effect on cervical cancer incidence and mortality. Cytology is an insensitive test for the detection of precancerous lesions (2) and is poorly reproducible (3). Its effectiveness in screening programs is the consequence of repeated screening to detect precancerous lesions during their slow progression to cervical cancer. The cervical cancer prevention program in the United States based on cytology screening, as successful as it is, comes at a significant price of $6 billion or more annually (4). The cost ineffectiveness of this program makes it unlikely for effective adoption in resource- limited regions. It is now widely recognized that cervical infections by f15 cancer-associated (carcinogenic) human papillomavirus (HPV) infections cause virtually all cervical cancer (5-7) and its immediate precursor, precancerous lesions (8). It is the failure to clear HPV infections and the subsequent progression of persistent carcinogenic HPV infections that are the key steps in cervical carcinogenesis (9). Based on this central role of persistent carcinogenic HPV infections in the development of cervical cancer, DNA tests for carcinogenic HPV have been developed, and one has been approved for use by the Food and Drug Administration. HPV DNA testing has proved to be more accurate, with greater sensitivity albeit slightly less specificity, than cervical cytology (2), and is much more reliable (10, 11). The improved clinical performance of HPV DNA testing compared with cervical cytology might be used to expand coverage of cervical cancer screening programs by combining self-collection of cervicovaginal specimens with HPV DNA testing. Self-collection with HPV DNA testing could be used to overcome some barriers to participation in screening programs such as the unwillingness of women to undergo pelvic exams or unwillingness to attending a screening clinic due to geographic or financial barriers. It can also reduce the cost and burden at the clinic by reducing the number of patients attending primary screening. Overcoming these barriers could be the most challenging, especially for women living in rural regions. However, with self-collection at home, it is important to maximize safety while preserving the specimen for many days until its return by mail or self-delivery to the laboratory for testing. Although liquid cytology medium might preserve a self-collected specimen for many days until a woman either mailed or self- delivered the specimen to the clinic or clinical lab, the toxicities of these buffers make their presence in the homes of reproductive-age women unacceptable. A safe and inexpensive method for the preservation of self- collected specimens is needed. Mouthwash has been used to collect buccal cells for genetic epidemiologic studies (12) and 840 Cancer Epidemiol Biomarkers Prev 2007;16(4). April 2007 Received 10/27/06; revised 1/8/07; accepted 1/29/07. Grant support: Intramural Research Program of the NIH, National Cancer Institute. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Requests for reprints: Philip E. Castle, Division of Cancer Epidemiology and Genetics, National Cancer Institute, 6120 Executive Boulevard, Room 5004, EPS MSC 7234, Bethesda, MD 20892-7234. Phone: 301-435-3976; Fax: 301-402-0916. E-mail: castlep@mail.nih.gov Copyright D 2007 American Association for Cancer Research. doi:10.1158/1055-9965.EPI-06-0909 on June 21, 2016. © 2007 American Association for Cancer Research. cebp.aacrjournals.org Downloaded from