Randomized Controlled Trial of Vaginal Self Sampling for Human Papillomavirus to Increase Cervical Cancer Screening Participation
Pap smear screening for cervical cancer precursors has substantially reduced the incidence
of invasive cervical cancer in Canada. While regular Pap screening can give up to 90%
protection against cervical cancer, about 30% of Canadian women do not participate in
Pap screening in Ontario is opportunistic. There are women who have family doctors and
regularly present for other medical issues at their physician's office but forego Pap smear
Numerous studies have shown that women are able to self collect vaginal samples, and that
these samples can be tested for the presence of oncogenic human papillomavirus. A recent
meta-analysis showed that HPV testing through physician collected samples had a sensitivity
of 80%-90% for detection of cervical intraepithelial neoplasia (CIN) 2 or worse, and a
specificity of 86%-95%. In comparison, a meta-analysis of self collected vaginal samples
tested for HPV showed a sensitivity of 74% and a specificity of 88%.
Studies have reported that women find self collection acceptable. However, we have found
that many women are more comfortable if a health care professional is available to help if
needed, and so this option should be provided for self-testing.
We are proposing a randomized controlled trial to see whether (a) the offer of a vaginal
self collection kit together with a second reminder for Pap testing will increase cervical
screening participation amongst "never-screened" and "hard to reach" women, as compared to
(b) a second reminder letter alone.
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Prevention
uptake of screening invitation
Alice Lytwyn, MD, FRCPC
Canada: Ethics Review Committee