Trial reportCancer2017
Early detection versus primary prevention in the PLCO flexible sigmoidoscopy screening trial: Which has the greatest impact on mortality?
Trial report in Cancer, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 11 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
11 citing papers in PubMed, 2 syntheses or guidelines pooled it, 24 citations in OpenAlex.
- The underestimated preventive effects of flexible sigmoidoscopy screening: re-analysis and meta-analysis of randomized trials.European journal of epidemiology · 2024Pooled it
- Pooled it
- Esomeprazole and aspirin in Barrett's oesophagus (AspECT): a randomised factorial trial.Lancet (London, England) · 2018Trial
- Endoscopic screening for colorectal cancer: efficacy versus effectiveness.Journal of the National Cancer Institute · 2026Article
- Contrasts in colorectal cancer incidence and mortality in screening trials of sigmoidoscopy vs the Nordic-European Initiative on Colorectal Cancer colonoscopy trial.Journal of the National Cancer Institute · 2025Article
- Novel colorectal cancer screening methods - opportunities and challenges.Nature reviews. Clinical oncology · 2025Review
- A Blood-Based Assay for Detection of Patients with Advanced Adenomas.Cancer research communications · 2025Article
- The Prognostic and Molecular Landscape of Autophagy-Related Long Noncoding RNA in Colorectal Cancer.BioMed research international · 2022Article
- Tumor DNA as a Cancer Biomarker through the Lens of Colorectal Neoplasia.Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology · 2020Article
- Contribution of Surveillance Colonoscopy to Colorectal Cancer Prevention.Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association · 2020Article
- CAIX aptamer-functionalized targeted nanobubbles for ultrasound molecular imaging of various tumors.International journal of nanomedicine · 2018Article
Corrections and comments
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Authors and funding
3 authors at 2 institutions in 1 country.
Funding
Abstract
backgroundScreening for colorectal cancer (CRC) with flexible sigmoidoscopy (FS) has been shown to reduce CRC mortality. The current study examined whether the observed mortality reduction was due primarily to the prevention of incident CRC via removal of adenomatous polyps or to the early detection of cancer and improved survival.
methodsThe Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial randomized 154,900 men and women aged 55 to 74 years. Individuals underwent FS screening at baseline and at 3 or 5 years versus usual care. CRC-specific survival was analyzed using Kaplan-Meier curves and proportional hazards modeling. The authors estimated the percentage of CRC deaths averted by early detection versus primary prevention using a model that applied intervention arm survival rates to CRC cases in the usual-care arm and vice versa.
resultsA total of 1008 cases of CRC in the intervention arm and 1291 cases of CRC in the usual-care arm were observed. Through 13 years of follow-up, there was no significant difference noted between the trial arms with regard to CRC-specific survival for all CRC (68% in the intervention arm vs 65% in the usual-care arm; P =.16) or proximal CRC (68% vs 62%, respectively; P = .11) cases; however, survival in distal CRC cases was found to be higher in the intervention arm compared with the usual-care arm (77% vs 66%; P<.0001). Within each arm, symptom-detected cases had significantly worse survival compared with screen-detected cases. Overall, approximately 29% to 35% of averted CRC deaths were estimated to be due to early detection and 65% to 71% were estimated to be due to primary prevention.
conclusionsCRC-specific survival was similar across arms in the PLCO trial, suggesting a limited role for early detection in preventing CRC deaths. Modeling suggested that approximately two-thirds of avoided deaths were due to primary prevention. Future CRC screening guidelines should emphasize primary prevention via the identification and removal of precursor lesions. Cancer 2017;123:4815-22. © 2017 American Cancer Society.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.