Role of the status of the mesorectal fascia in the selection of patients with rectal cancer for preoperative radiation therapy: a retrospective cohort study
Bibliographic record
Abstract
<h3>Background:</h3> Patients with rectal cancer in whom the mesorectal fascia is threatened by tumour are more likely than all patients with stage II/III disease to benefit from preoperative radiotherapy (RT). The objective of this study was to assess whether the status of the mesorectal fascia versus a stage II/III designation can best inform the use of preoperative RT in patients undergoing major rectal cancer resection. <h3>Methods:</h3> We reviewed the charts of consecutive patients with primary rectal cancer treated by a single surgeon at McMaster University, Hamilton, Ontario, between March 2006 and December 2012. The status of the mesorectal fascia was assessed by digital rectal examination, pelvic computed tomography and, when needed, pelvic magnetic resonance imaging (MRI). Patients whose mesorectal fascia was threatened or involved by tumour received preoperative RT. The study outcomes were rates of positive circumferential radial margin (CRM) and local tumour recurrence. <h3>Results:</h3> A total of 153 patients were included, of whom 76 (49.7%) received preoperative RT because of concerns of a compromised mesorectal fascia. The median length of follow-up was 4.5 years. The number of CRM-positive cases in the RT and no-RT groups was 16 (22%) and 1 (1%), respectively (<i>p</i> < 0.01), and the number of cases of local tumour recurrence was 5 (7%) and 2 (3%), respectively (<i>p</i> = 0.2). Rates were similar when only patients with stage II/III tumours were included. Overall, 26 patients (17.0%) received MRI. <h3>Conclusion:</h3> The status of the mesorectal fascia, not tumour stage, may best identify patients for preoperative RT.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".