Ovarian Cancer screening – update from UK trials
1University College London, London, England, UK
In the UK large ovarian cancer screening trials have been undertaken in both the general (United Kingdom Collaborative Trial of Ovarian Cancer Screening - UKCTOCS) and high-risk (UK Familial Ovarian Cancer Screening Study UKFOCSS) population. The 13 centre UKCTOCS is one of the largest individual randomised controlled trials. Between 2001-5, over 1.2 million women aged 50-74 were invited. 202,638 were randomised 2:1:1 to control(101,359), multimodal screening with serum CA125 interpreted using the Risk of Ovarian Cancer Algorithm (ROCA) with repeat CA125 and transvaginal ultrasound as second line tests (50,640) and ultrasound screening alone (50,639). Women underwent a median of 7 annual screens till December 2011. They were followed using data linkage to national registeries and postal questionnaires. 346,990 annual screens (50,708 women) were undertaken in the multimodal arm. Sensitivity (89% prevalence, 85% incidence) and specificity (99.8% prevalence, 99.8% incidence) for detection of invasive epithelial ovarian/fallopian tube cancer(iEOC) was encouraging. The use of ROCA appeared to double the number of screen-detected iEOC detected during incidence screening compared to a fixed cut off used previously. 328,894 annual screens (46,237 women) were undertaken in the ultrasound arm. Sensitivity (75% prevalence, 62% incidence) and specificity (98.2% prevalence, 99.7% incidence) were lower. About 40% of all screen detected iEOC in both arms were stage I/II.
In the high-risk population, the multimodal strategy with a shorter screening interval of four months was investigated in UKFOCSS Phase II. 4,531 women underwent 14,263 women years of screening between 2007-2012. Such intensive screening led to women recalled for abnormal results experiencing transient cancer-specific distress but there was no significant effect on general anxiety/depression or overall reassurance. The strategy had high sensitivity and specificity. 42% of screen-detected iEOC were stage I/II.
The key issue is impact on ovarian cancer mortality, which will be available from UKCTOCS in December 2015.