CAP
Cluster Randomized Trial of PSA Testing for Prostate Cancer
N = 415,357
- Population
- Men aged 50-69 years registered at 573 primary care practices (415,357 randomised men; 98% included in the analyses).
- Design
- Cluster-randomised trial: 573 primary care practices in the United Kingdom (England and Wales per the 2024 report) were randomised (2001 to 2007 per the 2024 report) and men aged 50-69 years were enrolled (2002 to 2009). Men at intervention practices received an invitation to attend a PSA testing clinic for a single PSA test, with a standardised diagnostic pathway (further tests if PSA was 3.0 ng/mL or higher); control practices provided standard unscreened practice (no invitation).
- Primary endpoint
- Prostate cancer mortality
- Arms
- Single PSA invitation (experimental, n = 195,912): Invitation to a PSA testing clinic and a single PSA test; diagnostic tests if PSA 3.0 ng/mL or higher
- Standard practice (control, n = 219,445): Standard practice without invitation to screening
- People
- Martin RM, CAP Trial Group
Δ Cumulative incidence of prostate cancer+0.7 pointsΔ Detection of low-grade prostate cancer (Gleason score 6 or lower)+0.6 pointsΔ Prostate cancer mortality−0.09 pointsΔ All-cause mortality−0.1 pointsΔ Cumulative incidence of prostate cancer+0.14 pointsΔ Detection of low-grade prostate cancer (Gleason score 6 or lower)+0.6 points
Show the numbers
| Endpoint | Analysis | Single PSA invitation | Standard practice | Effect |
|---|---|---|---|---|
| Cumulative incidence of prostate cancerMen included in the analysis (189,386 intervention; 219,439 control)Proportion of men diagnosed with prostate cancer by a median follow-up of 10 years (numbers diagnosed as a share of the men analysed, as printed in the 2018 abstract). | primarymedian follow-up 10 yearsMartin 2018 | 4.3% | 3.6% | P<.0018054 vs 7853 men diagnosed; rate ratio 1.19 (95% CI 1.14-1.25). Primary outcome in the same report, prostate-cancer mortality at a median of 10 years: 549 vs 647 deaths (0.30 vs 0.31 per 1000 person-years), rate ratio 0.96 (95% CI 0.85-1.08; P=.50). 40% of the intervention group attended the clinic. |
| Detection of low-grade prostate cancer (Gleason score 6 or lower)Men included in the analysis (189,386 intervention; 219,439 control)Proportion of men with a prostate cancer of Gleason grade 6 or lower identified, by a median follow-up of 10 years. | primarymedian follow-up 10 yearsMartin 2018 | 1.7% | 1.1% | P<.0013263 of 189,386 vs 2440 of 219,439; difference per 1000 men 6.11 (95% CI 5.38-6.84). Prespecified secondary outcome. |
| Prostate cancer mortalityMen included in the analyses (98% of 415,357 eligible men)Kaplan-Meier cumulative risk of death from prostate cancer at a median follow-up of 15 years (the 2024 full text states that these are cumulative risks). | long term-updatemedian follow-up 15 yearsMartin 2024 | 0.69% (0.65–0.73%) | 0.78% (0.73–0.82%) | P=.031199 deaths from prostate cancer in the intervention group and 1451 in the control group; rate ratio 0.92 (95% CI 0.85-0.99; P=.03 is for the rate ratio); risk difference -0.09% (95% CI -0.15 to -0.03; P=.02, full text). A secondary analysis (the primary outcome at a median of 10 years was reported in 2018); the abstract states the absolute reduction in deaths was small. Eight of the prostate-cancer deaths in the intervention group (0.7%) and 7 in the control group (0.5%) were related to a diagnostic biopsy or prostate cancer treatment. |
| All-cause mortalityMen included in the analyses (98% of 415,357 eligible men)Kaplan-Meier cumulative risk of death from any cause at a median follow-up of 15 years. | long term-updatemedian follow-up 15 yearsMartin 2024 | 23.2% (23.0–23.4%) | 23.3% (23.1–23.5%) | P=.1145,084 vs 50,336 deaths; rate ratio 0.97 (95% CI 0.94-1.01). |
| Cumulative incidence of prostate cancerMen included in the analyses (98% of 415,357 eligible men)15-year cumulative risk of a prostate cancer diagnosis. | long term-updatemedian follow-up 15 yearsMartin 2024 | 7.08% (6.95–7.21%) | 6.94% (6.82–7.06%) | 12,013 men with a prostate cancer diagnosis in the intervention group and 12,958 in the control group. |
| Detection of low-grade prostate cancer (Gleason score 6 or lower)Men included in the analyses (98% of 415,357 eligible men)Proportion of men diagnosed with Gleason score 6 or lower prostate cancer, by a median of 15 years. | long term-updatemedian follow-up 15 yearsMartin 2024 | 2.2% | 1.6% | P<.001Intermediate (Gleason score 7), high-grade (Gleason score 8 or higher), locally advanced (T3) and distally advanced (T4/N1/M1) tumours were not detected more often in the intervention group (as stated in the abstract). |
| Endpoint | Analysis | Single PSA invitation | Standard practice | Effect |
|---|---|---|---|---|
| Cumulative incidence of prostate cancerMen included in the analysis (189,386 intervention; 219,439 control)Proportion of men diagnosed with prostate cancer by a median follow-up of 10 years (numbers diagnosed as a share of the men analysed, as printed in the 2018 abstract). | primarymedian follow-up 10 yearsMartin 2018 | 4.3% | 3.6% | P<.0018054 vs 7853 men diagnosed; rate ratio 1.19 (95% CI 1.14-1.25). Primary outcome in the same report, prostate-cancer mortality at a median of 10 years: 549 vs 647 deaths (0.30 vs 0.31 per 1000 person-years), rate ratio 0.96 (95% CI 0.85-1.08; P=.50). 40% of the intervention group attended the clinic. |
| Detection of low-grade prostate cancer (Gleason score 6 or lower)Men included in the analysis (189,386 intervention; 219,439 control)Proportion of men with a prostate cancer of Gleason grade 6 or lower identified, by a median follow-up of 10 years. | primarymedian follow-up 10 yearsMartin 2018 | 1.7% | 1.1% | P<.0013263 of 189,386 vs 2440 of 219,439; difference per 1000 men 6.11 (95% CI 5.38-6.84). Prespecified secondary outcome. |
| Prostate cancer mortalityMen included in the analyses (98% of 415,357 eligible men)Kaplan-Meier cumulative risk of death from prostate cancer at a median follow-up of 15 years (the 2024 full text states that these are cumulative risks). | long term-updatemedian follow-up 15 yearsMartin 2024 | 0.69% (0.65–0.73%) | 0.78% (0.73–0.82%) | P=.031199 deaths from prostate cancer in the intervention group and 1451 in the control group; rate ratio 0.92 (95% CI 0.85-0.99; P=.03 is for the rate ratio); risk difference -0.09% (95% CI -0.15 to -0.03; P=.02, full text). A secondary analysis (the primary outcome at a median of 10 years was reported in 2018); the abstract states the absolute reduction in deaths was small. Eight of the prostate-cancer deaths in the intervention group (0.7%) and 7 in the control group (0.5%) were related to a diagnostic biopsy or prostate cancer treatment. |
| All-cause mortalityMen included in the analyses (98% of 415,357 eligible men)Kaplan-Meier cumulative risk of death from any cause at a median follow-up of 15 years. | long term-updatemedian follow-up 15 yearsMartin 2024 | 23.2% (23.0–23.4%) | 23.3% (23.1–23.5%) | P=.1145,084 vs 50,336 deaths; rate ratio 0.97 (95% CI 0.94-1.01). |
| Cumulative incidence of prostate cancerMen included in the analyses (98% of 415,357 eligible men)15-year cumulative risk of a prostate cancer diagnosis. | long term-updatemedian follow-up 15 yearsMartin 2024 | 7.08% (6.95–7.21%) | 6.94% (6.82–7.06%) | 12,013 men with a prostate cancer diagnosis in the intervention group and 12,958 in the control group. |
| Detection of low-grade prostate cancer (Gleason score 6 or lower)Men included in the analyses (98% of 415,357 eligible men)Proportion of men diagnosed with Gleason score 6 or lower prostate cancer, by a median of 15 years. | long term-updatemedian follow-up 15 yearsMartin 2024 | 2.2% | 1.6% | P<.001Intermediate (Gleason score 7), high-grade (Gleason score 8 or higher), locally advanced (T3) and distally advanced (T4/N1/M1) tumours were not detected more often in the intervention group (as stated in the abstract). |
Appears in
Sources
Martin RM, Donovan JL, Turner EL, Metcalfe C, Young GJ, Walsh EI, et al. Effect of a Low-Intensity PSA-Based Screening Intervention on Prostate Cancer Mortality: The CAP Randomized Clinical Trial. JAMA. 2018;319(9):883-895.
Martin RM, Turner EL, Young GJ, Metcalfe C, Walsh EI, Lane JA, et al. Prostate-Specific Antigen Screening and 15-Year Prostate Cancer Mortality: A Secondary Analysis of the CAP Randomized Clinical Trial. JAMA. 2024;331(17):1460-1470.