Oncologic Outcomes Following Laparoscopic versus Open Resection of pT4 Colon Cancer: A Systematic Review and Meta-analysis
Bibliographic record
Abstract
BACKGROUND: Locally advanced colon cancer is considered a relative contraindication for laparoscopic resection, and clinical trials addressing the oncologic safety are lacking. OBJECTIVE: The aim of this study was to synthesize the oncologic outcomes associated with laparoscopic versus conventional open surgery for locally advanced colon cancers. DATA SOURCES: We systematically searched Medline, Embase, Central, and ClinicalTrials.gov. STUDY SELECTION: Two reviewers independently screened the literature for controlled trials or observational studies comparing curative-intent laparoscopic and open surgery for colon cancer. Studies were included if it was possible to determine outcomes for the T4 colon cancers separately, either reported in the article or calculated with individual patient data. INTERVENTIONS: Included studies were systematically reviewed and assessed for risk of bias. Meta-analyses were done by using random-effects models. MAIN OUTCOME MEASURES: Outcomes of interest were disease-free survival, overall survival, resection margins, and lymph node harvest. RESULTS: Of 2878 identified studies, 5 observational studies met eligibility criteria with a total of 1268 patients (675 laparoscopic, 593 open). There was no significant difference in overall survival (HR, 1.28; 95% CI, 0.94-1.72), disease-free survival (HR, 1.20; 95% CI, 0.90-1.61), or positive surgical margins (OR, 1.16; 95% CI, 0.58-2.32) between the groups. The open group had a larger lymph node retrieval (pooled mean difference, 2.26 nodes; 95% CI, 0.58-3.93). The pooled rate of conversion from laparoscopy to an open procedure was 18.6% (95% CI, 9.3%-27.9%). LIMITATIONS: These results are limited by the inherent selection bias in the included nonrandomized studies. CONCLUSIONS: Based on the available literature, minimally invasive resection of selected locally advanced colon cancer is oncologically safe. There is a small increase in lymph node harvest with open resections, but it is unclear whether this is clinically significant. Surgeons should be prepared for a significant rate of conversion to laparotomy as required to perform en bloc resection.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.016 | 0.042 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.019 | 0.035 |
| Bibliometrics | 0.007 | 0.007 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.004 | 0.002 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".