Ovarian cancer screening effectiveness: A realization from the UK collaborative trial of ovarian cancer screening

Effects on survival in the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) was reported in The Lancet, and demonstrate that reductions in disease-specific mortality in this randomized control trial (RCT) indicate that ovarian cancer screening works. The UKCTOCS was large enough for sufficient accrual and follow-up, using two intervention arms: MMS (a multimodal strategy using the biomarker Ca125 combined with ultrasound as a secondary test) and USS (ultrasound alone) compared against a no-screen control group. MMS and USS performed similarly, showing a statistically significant reduction in mortality that increased with follow-up surveillance (8% reduction in years 0–7 vs 28% in years 7–14). The data led to the estimate that 641 screens are needed to prevent one ovarian cancer death.