CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-08-18). The draft was written by AI, the existence of all 1 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.7.
Verdict No. 2855 · Search date 2026-08-18 · Methodology v0.7

Transanal total mesorectal excision,
does it really help with Noninferior 3-year disease-free survival versus laparoscopic TME in mid-to-low rectal cancer?

30-Second Summary
B
Evidence Grade B · 76 · Safety caution
TaTME was noninferior to laparoscopic TME for three-year disease-free survival under expert credentialing
Both operations carry bleeding, anastomotic leak, infection, urinary and sexual dysfunction, stoma, and anesthesia risks. TaTME adds concerns about urethral or pelvic nerve injury, multifocal local recurrence, and a long learning curve, requiring credentialed high-volume teams.
What the
research shows
The grade is B. Three-year disease-free survival was 82.1% with TaTME and 79.4% with laparoscopic TME, an absolute difference of +2.7 points; the 97.5% CI of -3.0 to 8.1 stayed above the prespecified -10-point margin. One noninferiority-design limitation gives B with 76 points.
What the
ads claim
TaTME may improve access in a narrow pelvis, but it has a learning curve and prior safety controversy. Korean adoption requires minimum experience, video credentialing, multidisciplinary selection, and outcome surveillance.
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Useful facts when choosing a product

  • Three-year DFS was 82.1% versus 79.4%, absolute difference +2.7 points, 97.5% CI -3.0 to 8.1.
  • Three-year local recurrence was 3.6% versus 4.4%, HR 0.81, 95% CI 0.44-1.49.
  • Verdict 2851 compares laparoscopic with open surgery, 2852 addresses preoperative chemotherapy and radiation, and 2855 compares transanal with laparoscopic access. They ask different questions.
Gap Measurement · Verdict 2855 · B 76
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Eligible patients were randomized 1:1 through a web-based system using central allocation and center stratification. Each team needed at least 100 laparoscopic TME and 50 TaTME cases, with expected annual volumes of at least 50 and 30. A committee reviewed two unedited videos in obese men with low tumors. Defect name: Noninferiority-margin dependence. Listed item: Noninferiority design. Avoidability: Unavoidable - the question was whether a new approach preserved oncologic survival versus standard laparoscopy. Primary-analysis exclusion was 2.3% (26/1,115) and outcome missingness 1.3% (14/1,089), both below 15%. Sham surgery was unethical and not counted. Chinese public grants funded the trial and no author conflicts were reported.

02

Why this is classified as B (76)

A 1,115-person publicly funded hard-outcome RCT met its margin with one listed noninferiority limitation, giving B with 76 points.

Counterpoint. Early implementation reports raised local-recurrence concerns, so the technique should not be copied without the trial's expertise safeguards.

Rejudgment record. Cross-check applied — Large publicly funded hard-outcome RCT, strict surgeon credentialing, and one noninferiority-design limitation

Scoring profile behind this grade
EndpointHHard endpoint - actual events such as death
ReplicationR1Single confirmatory trial
IndependenceI2Decisive evidence is publicly or non-profit funded
Effect sizeE+Meets the clinically important threshold

The scoring table and the verdict agree (B).

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Noninferior three-year DFS in expert mid-to-low rectal cancer surgeryBThe -3.0-point CI lower bound stayed above the -10-point margin.
Equivalent safety during early learning curves or in low-volume hospitals?Not established because surgeons were strictly credentialed.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Study 1Chinese 16-center phase 3 randomized noninferiority trial1,089Chinese National Natural Science Foundation, Sun Yat-sen University 5010, and national or regional public grants; no conflicts and no funder role reportedThree-year DFS from intervention to disease or death from any cause; absolute margin -10 points82.1% versus 79.4%, absolute difference +2.7 points, 97.5% CI -3.0 to 8.1; HR 0.86, 97.5% CI 0.63-1.18Large publicly funded hard-outcome RCT with expert-surgeon conditions and noninferiority design
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Receipt — 1 References

All 1 cited sources were verified for existence at the original page (as of 2026-08-18).

Zeng Z, et al. Transanal Total Mesorectal Excision and 3-Year Disease-Free Survival in Mid-to-Low Rectal Cancer. JAMA. 2025. PMID: 39847361. PMCID: PMC11880948. DOI: 10.1001/jama.2024.24276.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-18 · Corrections: none

Cite this verdict

Transanal Total Mesorectal Excision Shows Noninferior 3-Year Disease-Free Survival in Mid-to-Low Rectal Cancer Evidence Grade B card
[Chamgap] Transanal Total Mesorectal Excision Shows Noninferior 3-Year Disease-Free Survival in Mid-to-Low Rectal Cancer — Evidence Grade B·76. 1 cited sources checked. Source: https://chamgap.com/en/verdicts/gut/transanal-versus-laparoscopic-tme-three-year-dfs/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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