Treatment patterns and outcomes of patients with pT3N0 rectal cancer in a population-based setting
Bibliographic record
Abstract
4039 Background: Adjuvant radiation (R) and chemotherapy (C) is generally recommended for patients (pts) with pT3N0 rectal cancer. Patterns of adjuvant therapy and outcomes among pts with pT3N0 rectal cancer referred to the British Columbia Cancer Agency (BCCA) were determined. Methods: The BCCA Colorectal Cancer Outcomes Unit database was used to identify referred pts with pT3N0 rectal carcinoma diagnosed between 2000–2004. During this period, “short course” R (25Gy/5, surgery within 10 days) was recommended for resectable cT3 tumors followed by 6 months of C. If not treated pre-operatively (pre-op), guidelines specified post-op “long course” (45Gy/25) R and C. Three treatment groups were identified: Surgery alone (S), S and R (SR), and S, R and C (SRC). Eligible pts had complete surgical resection with or without Total Mesorectal Excision (TME). Pts treated with “downstaging” pre-op long course R, with S and C only (13 pts) or with R2 resection were excluded. Locoregional Recurrence (LR) and Distant Recurrence (DR) rates determined. Reasons for non-treatment were determined by chart review. Results: 303 pts were identified, with median follow-up of 33.5 months. Significant differences in age, tumor height, grade, and R therapy existed between groups ( Table I ). TME status, R status and Radial Margin positivity were similar. LR rates were 15% (S), 2% (SR) and 1.4% (SRC). DR rates were 11.7% (S), 7.9% (SR) and 8.5% (SRC). Median Overall Survival (OS) and Disease Free Survival (DFS) was not reached. Conclusions: Treatment of pT3N0 rectal cancer was variable and significant heterogeneity existed between groups receiving S, SR and SRC. Nevertheless, LR rates were very low in pts receiving R and substantially higher in pts who did not. DR rates were similar across groups, irrespective of C history. Reasons for not receiving R or C were primarily patient related (medical/post- operative considerations, patient refusal). Potential physician related factors (non-referral) accounted for 28% of lack of C treatment in the SR group. [Table: see text] No significant financial relationships to disclose.
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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 | 0.000 | 0.001 |
| 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 | 0.001 | 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".