# UKCTOCS

Source: https://onco.cc/trials/ukctocs/  
OnCo record `ukctocs` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The largest screening trial ever run for ovarian cancer found earlier detection but no reduction in deaths, so there is still no recommended screening.

## Summary

Over 16 years of follow-up, multimodal screening shifted stage at diagnosis but did not reduce ovarian and tubal cancer deaths by a statistically significant margin (Lancet 2021). It is the central reason no guideline recommends population screening and why effort has moved to risk-reducing salpingectomy and multi-cancer blood tests.

## Fields

- Kind: Trial
- Status: negative
- Last checked: 2026-09-07
- Registry id: NCT00058032
- Phase: 3
- Setting: Postmenopausal women aged 50-74: annual multimodal (CA-125 algorithm + ultrasound) or ultrasound screening vs no screening
- Sponsor: UCL / MRC / CRUK
- Enrolled: 202638
- Result: No significant reduction in ovarian cancer mortality.
- Outcomes: Ovarian and tubal cancer mortality reduction (multimodal vs none): Multimodal screening 4%

## Sources

- ClinicalTrials.gov NCT00058032: https://clinicaltrials.gov/study/NCT00058032
- Lancet 2021: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00731-5/fulltext

## Connected records

- cancers: [Ovarian cancer](https://onco.cc/cancers/ovarian/)
- technologies: [Multi-cancer early detection (MCED)](https://onco.cc/technologies/mced/), [Serum tumour markers: proper use and misuse](https://onco.cc/technologies/serum-tumour-markers/), [Ultrasound](https://onco.cc/technologies/ultrasound/)
- companies: [MRC Clinical Trials Unit at UCL](https://onco.cc/companies/mrc-ctu/)
- institutions: [Cancer Research UK](https://onco.cc/institutions/cruk/)
- terms: [CA-125](https://onco.cc/terms/ca-125/), [Stage shift](https://onco.cc/terms/stage-shift/), [Surrogate endpoint](https://onco.cc/terms/surrogate-endpoint/), [Surrogate endpoint validation: which stand-ins have earned trust](https://onco.cc/terms/surrogate-validation/), [Why trials fail: underpowered, wrong endpoint, control arm drift, subgroup fishing, crossover](https://onco.cc/terms/trial-failure-modes/)
- people: [Usha Menon](https://onco.cc/people/usha-menon/)
- bottlenecks: [The hardest cancers are found late](https://onco.cc/bottlenecks/b-early-detection/)

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