Implementation of Organ Preservation for Locally Advanced Rectal Cancer in Canada: A National Survey of Clinical Practice
Bibliographic record
Abstract
PURPOSE: Organ preservation (OP) is an increasingly recognized treatment for locally advanced rectal cancer. However, variability in patient selection, treatment regimens, and surveillance can hinder widespread adoption. We conducted a national, cross-sectional survey evaluating how OP is implemented across Canada. METHODS: Between June and July 2023, surgeons, radiation oncologists, and medical oncologists with expertise in OP from all 44 Canadian radiation centers completed an electronic survey about the implementation of OP at their centers. Primary OP was defined as administering neoadjuvant therapy with the explicit goal of avoiding surgery. Secondary OP was defined as deferring planned surgery only when there was an unexpected yet sufficient clinical response. RESULTS: Responses from 40 radiation centers (response rate 90.9%) identified that 20 (50.0%) offered primary and secondary OP, 11 (27.8%) offered only secondary, and 8 (20.0%) offered neither. The most common treatment in primary OP was chemoradiation with consolidation chemotherapy (17/20, 89.5%). When assessing the response in primary OP, endoscopic biopsies were more commonly performed with a near-complete response (10/20, 50.0%) than a complete response (4/20, 20.0%). Watch-and-wait surveillance was more frequently offered for a complete response (17/31, 54.8%) than a near-complete response (4/31, 12.9%). Challenges included limited MRI (21/40, 52.5%), clinic time (18/40, 45.0%), timely surgery if required (16/40, 40.0%), and limited familiarity with the protocols and evidence (15/40, 37.5%). CONCLUSION: OP is recognized nationwide but is inconsistently implemented. Challenges raise concerns about the current feasibility of OP in Canada and highlight the need for less resource-intensive, complex OP protocols.
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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 | 0.001 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.004 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".