Improving diagnostic of cervical dysplasia among postmenopausal women aged ≥50 years using local vaginal oestrogen treatment prior to colposcopy: study protocol for a multicentre randomised controlled trial (the IDEAL study).

introductionColposcopy is the most important diagnostic tool to detect cervical precancerous lesions and thereby prevention of cervical cancer. Due to age-dependent changes of the cervix, colposcopy is challenging in postmenopausal women, as the majority will have a non-visible transformation zone, resulting in increased risk of missing disease, a diagnostic cone biopsy and prolonged follow-up with repeated colposcopies. This study will be among the first to investigate, if treatment with vaginal oestrogen prior to colposcopy will improve the colposcopy performance, to ensure accurate and timely diagnosis of precancerous cervical lesions among postmenopausal women. METHODS AND ANALYSIS: A randomised blinded controlled multicentre study. Enrolment will be performed at gynaecology departments in Central Denmark Region and Region of Southern Denmark. A total of 150 postmenopausal women aged ≥50 years referred for colposcopy due to abnormal cervical screening results will be randomised 1:1 to either pretreatment with vaginal application of Vagifem 30 µg or placebo once a day for 14 days prior to colposcopy. The primary outcome will be to compare the percentage of women in the two groups with a visible transformation zone at colposcopy, and biopsies representative of the transformation zone. Secondary outcomes will be the proportion of detected cervical intraepithelial neoplasia grade 2 or higher in the cervical biopsies; the proportion of diagnostics cone biopsies; the patients' report on possible side effects and compliance to the pretreatment. ETHICS AND DISSEMINATION: The study has been approved by the Central Denmark Region Committee on Biomedical Research Ethics (1-10-72-34-22), the Central Denmark Regions' Research Unit (1-16-02-72-22) and The Danish Health Authority (Danish Medicine Agency; 2022015030). The study's EudraCT number is (1-23-456; 2022-000269-42) and it is registered on www. CLINICALTRIALS: gov. The local Good Clinical Practice (GCP) unit will supervise and monitor the study closely before, during and after the study period. Findings will be disseminated in peer-reviewed scientific journals and presented in relevant conferences. TRIAL REGISTRATION NUMBER: NCT05283421.