Evaluation of self-collected cervicovaginal cell samples for human papillomavirus testing by polymerase chain reaction

As human papillomavirus (HPV) becomes accepted as the central cause of cerv ical cancer, longitudinal studies are shifting focus away from causality to a more detailed investigation of the natural history of HPV infections. Th ese studies commonly require repeated samples for HPV testing over several years, usually collected during a pelvic exam, which is inconvenient to the participants and costly to the study. To alleviate the inconvenience and c ost of repeated clinic visits, it has been proposed that women collect cerv icovaginal cells themselves, hopefully increasing participation in the natu ral history studies. We evaluated the technical feasibility of self-collect ion of cervicovaginal cells using a Dacron swab for HPV DNA detection. We c ompared the self-collected swab sample and two clinician-administered swab samples (one from the endocervix and another from the ectocervix) from a to tal of 268 women participating in a case-control study of adenocarcinoma an d squamous cell carcinomas of the uterine cervix (111 cases and 157 control s). HPV DNA was detected and genotyped using an L1 consensus PCR assay. The overall agreement between the clinician- and self-collected swabs was exce llent [88.1%; kappa = 0.73 (95% confidence interval (CI), 0.61-0.85)]. The correlation was highest between the two clinician-administered swabs [kappa = 0.81 (95% CI, 0.69-0.93)] but was still excellent when comparing either clinician-administered swab to the self-administered sample [kappa = 0.75 ( 95% CI, 0.63-0.87) and 0.67 (95% CI, 0.55-0.79) for ectocervix and endocerv ix, respectively], The type-specific agreement between samples was higher f or high-risk, or cancer-associated, HPV genotypes than for low risk, noncan cer-associated HPV genotypes when comparing the self-administered swab samp le to the clinician-administered swab sample (kappa = 0.78 for high-risk ve rsus 0.66 for low-risk HPV infections, t = -1.45, P = 0.15), The decrease i n agreement for low risk types was largely attributable to an increased det ection of these types in the self-administered sample (McNemar's chi (2) = 6.25, P = 0.01 for clinician- versus self-administered swab comparisons). T he agreement did not vary significantly by age, menopausal status, case sta tus, or clinic center, We have demonstrated that a self-collected Dacron sw ab sample of cervicovaginal cells is a technically feasible alternative to clinician-administered cervical cell collection in natural history studies of HPV and cervical cancer.