Dr NWJ Bulkmans
VU University Medical Center
Department of Pathology
De Boelelaan 1117
+31 (0)20 4440102
The main aims of the POBASCAM trial are to find out whether the efficacy and cost-effectiveness of the cervical screening programme can be improved by increasing the screening interval for women with normal cytology and a negative high-risk human papillomavirus (hrHPV) test, and by referring women with mild cytological abnormalities and a negative hrHPV test back to the next screening round, without increasing the risk of missing cervical intraepithelial neoplasia 3 (CIN3) lesions or cervical cancer.
Ethics approval received from the local medical ethics committee
Multicentre, randomised, triple blinded, active controlled, parallel group trial.
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Not available in web format, please use the contact details below to request a patient information sheet
Cervical intraepithelial neoplasia
In the POBASCAM trial, the addition of a high-risk human papillomavirus (hrHPV) test to the regular cervical screening programme to improve detection of precursor lesions of cervical cancer is evaluated in a randomised trial design.
During the trial, participants will receive either the regular test results and regular repeat and referral recommendations (control group, hrHPV test results blinded to participants, treating clinicians and study personnel) or participants will receive modified repeat and referral recommendations based on the presence or absence of hrHPV in the cervical smear (intervention group, hrHPV test results disclosed).
Primary outcome measures
The primary outcome measure of POBASCAM trial is the occurrence of histologically confirmed CIN3 lesions or (micro-) invasive carcinoma of the cervix found during the time span from intake up to and including the next screening round, i.e., in five years. Since women with normal cytology at the next screening round will not be referred for colposcopically-directed biopsies and therefore will not have a histological endpoint, it will be assumed that no precursor lesions of cervical cancer are present. This policy complies with regular cervical screening in The Netherlands.
Secondary outcome measures
As a secondary outcome measure, histologically confirmed cervical intraepithelial neoplasia grade 2 will also be investigated, since current guidelines recommend ablative treatment for these lesions as well. Other secondary parameters obtained include progression and regression of cytology diagnoses, clearance and acquisition of hrHPV infections and the number of referrals for colposcopically-directed biopsies.
Overall trial start date
Overall trial end date
Participant inclusion criteria
1. Women invited for the cervical cancer screening program (ages 30 - 60 years)
2. Residing in either the region covered by district health authority Amstelland-de Meerlanden and Zuid-Kennemerland
Target number of participants
Participant exclusion criteria
1. Not called for screening, ie ages under 30 years, or over 60 years
2. Follow-up of previous non-normal cytology within the current screening round of the program, i.e., abnormal cytology or CIN lesions less than two years before inclusion
3. Status after extirpation of the uterus or amputation of the portio
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
VU University Medical Center,
The Netherlands Organization for Health Research and Development (ZonMw) (The Netherlands)
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Results - basic reporting
1. Design, methods and baseline data: http://www.ncbi.nlm.nih.gov/pubmed/15054873
2. 2005 results in http://www.ncbi.nlm.nih.gov/pubmed/15900579
3. 2007 five-year follow up in http://www.ncbi.nlm.nih.gov/pubmed/17919718
4.. 2012 final results in http://www.ncbi.nlm.nih.gov/pubmed/22177579
Bulkmans NW, Bleeker MC, Berkhof J, Voorhorst FJ, Snijders PJ, Meijer CJ, Prevalence of types 16 and 33 is increased in high-risk human papillomavirus positive women with cervical intraepithelial neoplasia grade 2 or worse., Int. J. Cancer, 2005, 117, 2, 177-181, doi: 10.1002/ijc.21210.
Bulkmans NW, Rozendaal L, Snijders PJ, Voorhorst FJ, Boeke AJ, Zandwijken GR, van Kemenade FJ, Verheijen RH, v Groningen K, Boon ME, Keuning HJ, van Ballegooijen M, van den Brule AJ, Meijer CJ, POBASCAM, a population-based randomized controlled trial for implementation of high-risk HPV testing in cervical screening: design, methods and baseline data of 44,102 women., Int. J. Cancer, 2004, 110, 1, 94-101, doi: 10.1002/ijc.20076.
Bulkmans NW, Berkhof J, Rozendaal L, van Kemenade FJ, Boeke AJ, Bulk S, Voorhorst FJ, Verheijen RH, van Groningen K, Boon ME, Ruitinga W, van Ballegooijen M, Snijders PJ, Meijer CJ, Human papillomavirus DNA testing for the detection of cervical intraepithelial neoplasia grade 3 and cancer: 5-year follow-up of a randomised controlled implementation trial., Lancet, 2007, 370, 9601, 1764-1772, doi: 10.1016/S0140-6736(07)61450-0.
Rijkaart DC, Berkhof J, Rozendaal L, van Kemenade FJ, Bulkmans NW, Heideman DA, Kenter GG, Cuzick J, Snijders PJ, Meijer CJ, Human papillomavirus testing for the detection of high-grade cervical intraepithelial neoplasia and cancer: final results of the POBASCAM randomised controlled trial., Lancet Oncol., 2012, 13, 1, 78-88, doi: 10.1016/S1470-2045(11)70296-0.