March 5, 2016: Editorial - UKCTOCS and the evaluation of screening for ovarian cancer

Editorial- The Lancet
 

Ovarian cancer is the fifth most common cause of cancer-related death in women in Europe. Vague symptoms mean that most women present with advanced disease, so that 5-year survival is less than 40%. Progress in the past generation has been slow, with little added benefit from biomarkers, mechanism-based treatments, or surgical innovations. Recently, emphasis has shifted to earlier diagnosis with clinical decision aids and population screening—a challenging proposition for a disease of low prevalence and without a recognisable latent phase. Therefore, results of the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS), published in today's Lancet, have been highly anticipated: if ovarian cancer can be detected earlier by screening and treated more promptly, might medicine finally gain the upper hand against this stubborn illness?

Maybe. At a median 11 years' follow-up of the 202 638 women allocated to annual screening by either transvaginal ultrasound, a multimodal combination of CA125 augmented with ultrasound, or to no screening, the primary outcome of death due to ovarian cancer was not significantly different. Further analyses suggested that there may be a late survival advantage from screening, but longer follow-up is needed.

Although full understanding of screening in ovarian cancer and its cost-effectiveness will take longer to establish, the successful conclusion of UKCTOCS represents a major achievement for clinical science in the NHS. First, it affirms the importance of science-based priority setting (the NHS Health Technology Assessment programme identified the need for such a trial in 1998). Second, it shows boldness in recognising that very large-scale, publicly funded, randomised trials are needed in some situations of equipoise—and that by asking the right question at the right time, widespread collaboration is possible. Third, it is a testimony to the trial organisation and investigators, that they achieved around 80% compliance and 99% follow-up. The philosophy that underpinned UKCTOCS is a crucial part of an integrated health service and should be applauded and fostered.