HPV DNA Testing of Self-collected Vaginal Samples Compared With Cytologic Screening to Detect Cervical Cancer

Abstract

CONTEXT: More than half of the women diagnosed as having cervical cancer in the United States have not been screened within the last 3 years, despite many having had contact with the health care system. In many other regions of the world, there is only limited access to cervical cancer screening. OBJECTIVE: To determine whether testing of self-collected vaginal swabs for human papillomavirus (HPV) DNA can be used to screen for cervical disease in women aged 35 years and older. DESIGN: Cross-sectional observational study comparing Papanicolaou smears with HPV DNA testing of self-collected vaginal swabs. SETTING: Outpatient clinics in a periurban settlement outside of Cape Town, South Africa, between January 1998 and April 1999. PARTICIPANTS: Screening was performed on 1415 previously unscreened black South African women aged 35 to 65 years. INTERVENTION: Women self-collected a vaginal swab for HPV testing in the clinic and were then screened using 4 different tests: Papanicolaou smear, direct visual inspection of the cervix after the application of 5% acetic acid, cervicography, and HPV DNA testing of a clinician-obtained cervical sample. Women with abnormal results on any of the screening tests were referred for colposcopy. MAIN OUTCOME MEASURE: Biopsy-confirmed high-grade cervical squamous intraepithelial lesions or invasive cancer. RESULTS: High-grade squamous intraepithelial lesions were identified in 47 (3.4%) of 1365 women adequately assessed, and there were 9 cases of invasive cancer. Of women with high-grade disease, 66.1% (95% confidence interval [CI], 52.1%-77.8%) had high risk for HPV detected in self-collected vaginal samples, and 67.9% (95% CI, 53.9%-79.4%) had an abnormal Papanicolaou smear (P = .78). The false-positive rates for HPV DNA testing of self-collected vaginal samples and Papanicolaou smears were 17.1% (95% CI, 15.1%-19.3%) and 12.3% (95% CI, 10.5%-14.2%), respectively (P<.001). A high-risk type of HPV DNA was detected in 83.9% (95% CI, 71.2%-91.9%) of women with high-grade disease and 15.5% (95% CI, 13.6%-17.7%) of women with no evidence of cervical disease using a clinician-obtained cervical sample. CONCLUSIONS: These results indicate that HPV testing of self-collected vaginal swabs is less specific than but as sensitive as Papanicolaou smears for detecting high-grade cervical disease in women aged 35 years and older, and HPV testing offers an important new way to increase screening in settings where cytology is not readily performed.