Evidence map›Paper›PMID 42765562›Full record

SynthesisBJS open2026

Methodological challenges in surgical randomized trials: systematic review of rectal cancer studies.

Daichi Kitaguchi, Mariano Giménez, Antonello Forgione, Tatsuya Oda, Jacques Marescaux

Abstract readSystematic Review
In one paragraph

Synthesis in BJS open, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from 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.

2 · The registry

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.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Daichi KitaguchiResearch Institute Against Digestive Cancer (IRCAD), Strasbourg, France.
Mariano GiménezResearch Institute Against Digestive Cancer (IRCAD), Strasbourg, France.
Antonello ForgioneResearch Institute Against Digestive Cancer (IRCAD), Strasbourg, France.
Tatsuya OdaDepartment of Gastrointestinal and Hepatobiliary and Pancreatic Surgery, Institute of Medicine, University of Tsukuba, Tsukuba, Japan.
Jacques MarescauxResearch Institute Against Digestive Cancer (IRCAD), Strasbourg, France.

Funding

Japan Agency for Medical Research and Development JP256f0137008JSPS JP23K17185
6 · The paper itself

Abstract

backgroundSurgical randomized clinical trials (RCTs) have structural features that differ fundamentally from those of non-surgical trials, which may complicate appraisal using standard assessment frameworks. This methodological systematic review used rectal cancer surgery RCTs as a high-complexity exemplar to identify surgically specific methodological challenges and to examine their interaction with established tools for assessing risk of bias and certainty of evidence.

methodsA systematic literature search was conducted in PubMed, Embase, and the Cochrane Library on 1 November 2025. Eligible studies were RCTs evaluating surgery-related interventions for rectal cancer in adult patients, published in English from 2020 onward, with sufficient methodological detail. Included trials were categorized into predefined, mutually exclusive surgical RCT types. Methodological features were descriptively summarized and conceptually mapped to the domains of the revised Cochrane Risk of Bias (RoB 2) tool and the GRADE framework using both quantitative tabulation and narrative synthesis.

resultsOf 1529 records identified, 45 publications reporting on 35 RCTs were included. Trials were classified into five surgical RCT categories. Surgically specific methodological challenges were most frequently observed in RoB 2 domains D2 (bias due to deviations from intended interventions) and D4 (bias in measurement of the outcome), as well as in the GRADE domain of indirectness.

conclusionThis review suggests that several challenges encountered when applying RoB 2 and GRADE to surgical RCTs arise from structural characteristics of surgical trial design rather than obvious methodological shortcomings. Contextualizing standard appraisal frameworks within the realities of surgical research may allow for a more nuanced interpretation of existing evidence, inform future trial design, and support more appropriate evidence synthesis.

Indexed as

Randomized Controlled Trials as TopicRectal NeoplasmsResearch DesignBiasColorectal Surgical ProceduresHumansbiasGRADE approachoperativerandomized clinical trialrectal neoplasmssurgical procedures

Identifiers

PMID42765562
PMCPMC13591274

What OpenQuestion holds

Textmetadata
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Registered trials

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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.