# PLCO, prostate component (Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial)

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

## TL;DR

The American screening trial that found no benefit, and the reason is the trial itself: half the men in the group that was supposed to go unscreened were getting PSA tests from their own doctors.

## Summary

PLCO randomised 76,693 men at ten United States centres between 1993 and 2001 to annual prostate-specific antigen testing for six years with digital rectal examination for four years, or to usual care. Compliance in the screened group was 85 percent for PSA and 86 percent for rectal examination.

The finding that matters for reading the result is in the control group: PSA testing there rose from 40 percent in the first year to 52 percent in the sixth, with rectal examination in 41 to 46 percent. The trial therefore compared organised annual screening with widespread opportunistic screening, not with no screening at all.

After seven years the incidence of prostate cancer was 116 per 10,000 person-years in the screened group against 95 in the control group, and the death rate was 2.0 against 1.7 per 10,000 person-years, a rate ratio of 1.13 that was not significant. The ten-year data, 67 percent complete at the time of the report, were consistent.

## Fields

- Kind: Trial
- Status: negative
- Last checked: 2026-09-25
- Also known as: PLCO; PLCO prostate; Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial
- Registry id: NCT00002540
- Phase: 3
- Setting: Population screening: men randomised at ten United States centres to annual PSA testing for six years with digital rectal examination for four, or to usual care, with death from prostate cancer as the outcome
- Sponsor: National Cancer Institute
- Result: Prostate cancer death rate 2.0 against 1.7 per 10,000 person-years, rate ratio 1.13 (95 percent confidence interval 0.75 to 1.70), not significant; control-group PSA testing rose from 40 to 52 percent over the six screening years.
- Outcomes: Death from prostate cancer at 7 years: Annual PSA and digital rectal examination 2 per 10,000 person-years vs Usual care 1.7 per 10,000 person-years, HR 1.13; Prostate cancer incidence at 7 years: Annual PSA and digital rectal examination 116 per 10,000 person-years vs Usual care 95 per 10,000 person-years
- Replication: ERSPC, reported in the same issue of the same journal on the same day, found a 20 percent reduction in prostate cancer mortality. The difference between the two is usually attributed to PLCO's contaminated control arm, its shorter screening interval and its higher PSA threshold for biopsy.

## Sources

- PLCO prostate mortality (New England Journal of Medicine 2009): https://doi.org/10.1056/NEJMoa0810696
- ClinicalTrials.gov NCT00002540: https://clinicaltrials.gov/study/NCT00002540

## Connected records

- cancers: [Prostate cancer](https://onco.cc/cancers/prostate/)
- terms: [Overdiagnosis](https://onco.cc/terms/overdiagnosis/), [PSA (prostate-specific antigen)](https://onco.cc/terms/psa/)
- trials: [ERSPC (European Randomized Study of Screening for Prostate Cancer)](https://onco.cc/trials/erspc/)

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