A Randomized Controlled Evaluation of HPV Testing for Cervical Cancer Screening
There is now an overwhelming body of data to show that HPV testing has the potential to
improve the effectiveness of cervical cancer screening programs and thereby reduce rates of
cervical cancer. As a result, there is a growing ethical dilemma in that we potentially have
the means to prevent disease and death among Canadian women, and yet the studies that have
been undertaken do not offer the standard of evidence that is required to change large-scale
public health programs such as cervical cancer screening. In recognition of this, the
Pan-Canadian Cervical Cancer Forum (PCCCF) has called for the evaluation of HPV testing
within the context of a Canadian organised cervical cancer screening program. Given the
potential health benefits that could be achieved, and that a pan-Canadian expert group has
issued a consensus statement calling for the evaluation of HPV testing for primary
screening, it is now an imperative that a properly designed and powered study be conducted
to definitively establish whether it will provide the hypothesised health benefits within
The results of this trial will demonstrate whether or not the use of HPV testing as a single
primary screening test within an organised Canadian cervical cancer screening program will
be able to 1) provide further reductions in cervical cancer incidence, 2) allow the
screening interval to be extended and 3) improve the cost-effectiveness of cervical cancer
screening. If this trial demonstrates that HPV testing will provide these benefits, the BCCA
will implement HPV testing as a single primary screening test within the provincial cervical
cancer screening program and the trial will directly influence the provision of this service
in BC. In addition, many other Canadian provinces and territories are either implementing or
have plans to implement screening programs similar to the one in BC and by the time this
trial is completed, many will have these programs operating. Therefore, the results of this
trial will be directly applicable to these programs and constitute a demonstration project
for the rest of Canada.
A list of women who are due for cervical screening will be sent to study collaborating
Family Physicians (FPs) each month from the study centre in the provincial screening
program. An invitation letter will be sent by the FP to potentially eligible women due for
cervical cancer screening. If women are interested in participating, they will contact the
study centre for more information. Study staff discuss the details of the trial with them,
confirm eligibility and administer a short survey. Women who consent to the trial will visit
the FP for their screening test and samples will be obtained and sent to the BC Central
Laboratory Service (BC-CLS) where it will be randomized into one of the study arms:
Note: Recruitment to the safety arm was complete December 31, 2010 and from that point
forward, women randomized 1:1 into the control or intervention arms only. A total of ~25,000
women (~9140 each in the Control and Intervention arms respectively, and ~6,000 in the
Safety arm) will be enrolled in the FOCAL trial.
Sample tested with LBC.
- Those with negative results will be recalled for next screen at 2 years and if
negative again, for the exit screen at 4 years. Those with positive cytology results
have reflex HPV testing, or referral to colposcopy based on results.
- Exit screen testing is both HPV and cytology testing
2-year safety-check arm: Sample tested for HPV.
- HPV negatives recalled at 2-years for the exit screen with cytology
- Women who are HPV positive will have their residual LBC specimen processed for cytology
and be managed according to the same protocol as HPV-positive women in the 4-year
4-year intervention arm: Sample tested for HPV.
- HPV negatives will be recalled at 4 years for their exit screen with HPV and cytology
- Women who are HPV positive will undergo reflex cytology testing and those cytology
negative will be recalled at 12 months for HPV testing and cytology. At 12 mos,
participants will be referred to colposcopy if > or =ASC-US or HPV positive. If HPV and
cytology negative at 12 months returned to the routine screening pool for this arm and
recalled for the exit screen at 4-years.
- Women who are HPV positive and > or = ASC-US will be referred to colposcopy and managed
according to colposcopy results.
Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Subject), Primary Purpose: Diagnostic
Histologically confirmed greater than or equal to CIN2 detected at 2 years in both the control and the safety-check arms.
Andrew Coldman, MD
University of British Columbia
Canada: Health Canada