Association of adjuvant chemotherapy with clinical outcomes in patients treated with neoadjuvant chemoradiation for locally advanced rectal cancer.
Bibliographic record
Abstract
3628 Background: Clinical trial data does not support the routine use of adjuvant chemotherapy (ACT) following neoadjuvant chemoradiation (nCRT) and surgery (Sx) in rectal cancer (Ca). Few studies have included oxaliplatin-based ACT or assessed the benefit in specific pathologic stage (Pstage) subgroups. Methods: Data from patients (pts) with locally advanced rectal Ca who received nCRT and had curative intent Sx from 2005 to 2012 were collected from Tom Baker Cancer Center, Cross Cancer Institute, BC Cancer Agency, Ottawa Hospital Cancer Centre and Dr. H. Bliss Murphy Cancer Centre. The effect of ACT on Time Free of Recurrence (TFR – death without recurrence censored), Disease Free Survival (DFS) and Overall Survival (OS) was assessed using cox proportional hazards model, controlling for age, sex, performance status (PS), circumferential resection margin (CRM), location of tumor, RT dose, Clinical stage (Cstage), Pstage. Results: 1172 pts were included, with a mean age of 61.6 (± 0.33) and a mean follow-up time of 3.8 years (± 0.05). 303 (25.9%) pts received oxaliplatin-based ACT, while 328 (28%) did not receive any ACT and these pts were more likely to be older (65.8 v 65 yrs, p<0.0001), have worse PS (p=0.009), receive lower doses of RT (p=0.0003) and have earlier Cstage (p=0.004) on univariate analysis compared with ACT pts. Univariate analyses for Pstage 0-II were non-significant (NS) for effect of ACT on TFR and DFS. See Table for all pts and Pstage III outcomes controlling for covariates above. Assessment of ACT in high risk v low risk stage II (as in colon Ca) was NS for TFR (p=0.47), DFS (p=0.7) and OS (p=0.7) adjusting for age, PS and CRM. Conclusions: ACT improved clinical outcomes in our retrospective database, however the benefits may be limited to those with Pstage III. Studies are needed to clarify if factors used to stratify stage II colon Ca into high vs. low risk may be applied to estimate recurrence risk in Pstage II rectal Ca. Population TFR (95% CIs) p-value DFS (95% CIs) p-value OS (95% CIs) p-value All pts ACT v no ACT 0.84 (0.59 – 1.18) 0.31 0.63 (0.47 –0.85) 0.002 0.52 (0.36 – 0.75) 0.0004 Pstage III ACT v no ACT 0.6 (0.39 – 0.93) 0.02 0.53 (0.35 – 0.8) 0.002 0.48 (0.29 – 0.79) 0.004
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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 | 0.003 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".