Utilization and effectiveness of adjuvant chemotherapy (ACT) for colon cancer (CC) in the general population.
Bibliographic record
Abstract
702 Background: International guidelines recommend ACT for patients (pts) with stage III CC based on level I evidence showing improved survival. For stage II CC ACT is not routinely recommended but may be considered for pts with high-risk features. Here we describe practice patterns and outcomes associated with ACT in a routine population-based setting. Methods: All CC cases treated with surgery in Ontario 2002-2008 were identified using the population-based Cancer Registry. Electronic treatment records were linked to the registry to identify surgical procedures and utilization of ACT. Pathology reports were obtained for a 25% random sample of all cases to obtain details of extent of disease; pts with stage II or III were included in the study population. High-risk stage II was defined as: T4, <12 lymph nodes, poorly differentiated histology and/or lymphovascular invasion. Logistic regression was used to evaluate factors associated with ACT utilization. Cox proportional hazards model was used to evaluate cancer-specific (CSS) and overall (OS) survival. Results: The study population included 2,801 stage III and 2,488 stage II pts (47% of which were high-risk). In the stage III subgroup 66% received ACT, but was 90% among ages 20-49 vs 68% for ages 70-79 (p<0.001). ACT was associated with increased CSS (HR 0.63, 95% CI 0.54-0.73) and OS (HR 0.63, 95% CI 0.55-0.71). Among all stage II pts 18% received ACT but 24% in the high-risk disease subset. ACT utilization was higher in younger patients (51% for ages 20-49 vs. 16% ages 70-79, p<0.001) and varied across geographic regions (range 10-39%, p<0.001). Among all stage II pts ACT was not associated with improved CSS (HR 1.41, 95%CI 1.09-1.82) or OS (HR 1.16, 95%CI 0.94-1.42). Stratified analysis for high-risk stage II disease also did not show benefit to ACT (CSS HR 1.14, 95%CI 0.84-1.55; OS HR 1.02, 95%CI 0.79-1.31). Conclusions: One third of pts with stage III CC in the general population do not receive ACT, with age the strongest predictor of treatment. For stage II pts, ACT utilization varies substantially across age groups and geographic regions. ACT is associated with improved CSS and OS in stage III pts but not stage II pts, including those with high-risk disease.
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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 | 0.001 |
| 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) | 0.001 | 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".