HPV DNA testing of self-collected vaginal samples compared with cytologic screening to detect cervical cancer.

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.