VANCOUVER, British Columbia -- Asking patients to collect their own vaginal specimens for HPV testing proved an effective initial screening method among high-risk women, researchers here found.
VANCOUVER, British Columbia, Aug. 27 -- Asking patients to collect their own vaginal specimens for HPV testing proved an effective initial screening method among high-risk women, researchers here found.
Women screened in the study were twice as likely to have high-risk human papillomavirus infections as the general population but less likely to have ever had a Papanicolaou smear (P<0.05), found Gina Ogilvie, M.D., M.Sc., of the British Columbia Center for Disease Control, and colleagues.
"Self-collected specimens may not possess the same degree of diagnostic accuracy as clinician-collected specimens," they wrote in the Aug. 28 issue of the Canadian Medical Association Journal.
"However, this limitation is outweighed by the increased uptake of HPV testing among hard-to-reach women," they said.
The researchers sent outreach nurses to Vancouver's Downtown Eastside to seek out sexually active women ages 17 or older who were homeless or had unstable housing, were involved in the sex trade, or had a history of alcohol or drug abuse.
The nurses approached women in shelters, women's centers, and alleys. Their standardized recruitment statement included advising the women to have a follow-up Papanicolaou (Pap) smear within a year, because self-collected specimens are not standard for cervical cancer screening.
For specimen collection, participants were told to go immediately to the closest bathroom or private location, insert a Dacron swab intravaginally, rotate it three times, put it in a specimen tube, and return it to the nurse.
The samples were sent within 24 hours to the British Columbia Center for Disease Control for testing.
They were able to collect and analyze specimens from 151 women, just over half of those approached by the nurses from November 2004 to October 2005.
More than a quarter of the women tested positive for high-risk, cancer-causing HPV strains (28.5%, 95% confidence interval 21.2% to 35.4%). This was twice the prevalence reported by the Cervical Cancer Screening Program for the general population in British Columbia (13.9%) although the median age was similar in both studies (39 versus 40).
Likewise, women in Dr. Ogilvie's study were significantly less likely to have ever had a Pap smear in British Columbia compared with the general population in the province (13.9% versus 8.3%, P<0.05).
Only 53.6% of the study participants (81 of 151) had received a Pap smear in the preceding three years. This was significantly lower than self-reported rates for British Columbia from the Canadian Community Health Survey and from the province's Cervical Cancer Screening Program, the researchers said.
Women who tested positive for high-risk HPV were also significantly younger (median 35 versus 41, P=0.007) and reported more sex-trade partners than women who tested negative (44.2% versus 25.9% had at least 11 in the month prior to testing, P<0.05).
After high-risk HPV status was determined in the lab, the outreach nurses again sought out the women. They were able to contact 81.4% of those who had tested positive and refer them for further testing.
Further studies are needed to see what the rate of follow-up testing is for women screened with the self-collection method, they said.
But, the method could be useful in developing countries, they concluded.
"Given the high incidence of this preventable cancer in developing countries, self-collection of specimens for HPV screening could be offered as a component of reproductive health programs and could be administered by health care workers to improve access to cervical cancer screening," they wrote.
"Follow-up using screen-and-treat methods could then be used to offer definitive treatment for women at risk for cervical cancer," they added.