Final Results of the GRECCAR-6 Trial on Waiting Period Following Neoadjuvant Radiochemotherapy for Locally Advanced Rectal Cancer: 5 Years of Follow-up
Bibliographic record
Abstract
BACKGROUND: The potential oncological benefit of extending the waiting period between neoadjuvant radiochemotherapy and surgical resection for rectal cancer is debated. OBJECTIVE: To evaluate the impact of prolonging this waiting period on the 5-year oncological prognosis and 2-year functional result of locally advanced rectal adenocarcinoma. DESIGN: Phase III, multicenter, randomized, open-label, parallel-group, controlled trial. SETTINGS: Patients were enrolled from 24 colorectal centers. PATIENTS: Patients with nonmetastatic mid or lower cT3/T4Nx or cTxN+ rectal adenocarcinoma who had received radiochemotherapy (45-50 Gy radiation dose with fluorouracil or capecitabine). INTERVENTION: Patients were randomly assigned to undergo total mesorectal excision either 7 weeks or 11 weeks after radiochemotherapy. MAIN OUTCOMES MEASURES: Overall survival and disease-free survival at 5-year follow-up and low anterior resection syndrome score assessed after 2 years of follow-up. RESULTS: Among 265 patients enrolled, 133 were randomized in the 7-week group and 132 in the 11-week group. Twelve patients were excluded because they did not undergo resection. Among 253 patients analyzed, 5-year overall survival was not different between the 2 groups (81.6% in the 7-week group vs 82.6% in the 11-week group, p = 0.827), and neither was the 5-year disease-free survival (70.4% in the 7-week group vs 69.5% in the 11-week group, p = 0.856). No difference was observed between the 2 groups for distant recurrence (27.4% in the 7-week group vs 25.7% in the 11-week group, p = 0.777) or local recurrence (8.4% in the 7-week group vs 10.2% in the 11-week group, p = 0.543). The low anterior resection syndrome score was similar between the 7-week (25.0; interquartile range, 15.0-34.0) and 11-week groups (23.0; interquartile range, 14.2-32.0; p = 0.743). LIMITATIONS: The response rate to the low anterior resection syndrome questionnaire was only 52%. CONCLUSIONS: Extending the waiting period between radiochemotherapy and resection from 7 to 11 weeks does not change the 5-year oncological prognosis in rectal cancer or the 2-year low anterior resection occurrence. See Video Abstract. RESULTADOS FINALES DEL ENSAYO GRECCAR SOBRE EL PERODO DE ESPERA TRAS LA RADIOQUIMIOTERAPIA NEOADYUVANTE PARA EL CNCER DE RECTO LOCALMENTE AVANZADO AOS DE SEGUIMIENTO: ANTECEDENTES:Se debate el posible beneficio oncológico de prolongar el periodo de espera entre la radioquimioterapia neoadyuvante y la resección quirúrgica del cáncer de recto.OBJETIVO:Evaluar el impacto de la prolongación de este periodo de espera sobre el pronóstico oncológico a 5 años y el resultado funcional a 2 años del adenocarcinoma rectal localmente avanzado.DISEÑO:Ensayo controlado de fase III, multicéntrico, aleatorizado, abierto, de grupos paralelos.LUGAR:Se reclutaron pacientes de 24 centros colorrectales.PACIENTES:Pacientes con adenocarcinoma rectal de tercio medio o inferior, no metastásico cT3-4 o TxN+ que habían recibido radioquimioterapia (45 a 50 Gy con fluorouracilo o capecitabina).INTERVENCIÓN:Se asignaron aleatoriamente a los pacientes para ser sometidos a una escisión mesorrectal total 7 semanas (W7) u 11 semanas (W11) después de la radioquimioterapia.MEDIDAS DE RESULTADOS PRINCIPALES:Supervivencia global y supervivencia libre de enfermedad a los 5 años de seguimiento y puntuación del síndrome de resección anterior baja evaluada a los 2 años de seguimiento.RESULTADOS:De los 265 pacientes reclutados, 133 fueron asignados aleatoriamente al grupo de 7 semanas y 132 al grupo de 11 semanas. Doce pacientes fueron excluidos porque no fueron sometidos a resección. Entre los 253 pacientes analizados, la supervivencia global a 5 años no fue diferente entre los dos grupos (81,6% en el grupo de 7 semanas frente a 82,6% en el grupo de 11 semanas, p = 0,827), así como para la supervivencia libre de enfermedad a 5 años (70,4% en el grupo de 7 semanas frente a 69,5% en el grupo de 11 semanas, p = 0,856). No se observaron diferencias entre los dos grupos en cuanto a la recidiva a distancia (27,4% en el grupo de 7 semanas frente a 25,7% en el grupo de 11 semanas, p = 0,777) o la recidiva local (8,4% en el grupo de 7 semanas frente a 10,2% en el grupo de 11 semanas, p = 0,543). La puntuación del síndrome de resección anterior baja fue similar entre los grupos de 7 semanas (25,0 IQR [15,0-34,0]) y 11 semanas (23,0 IQR [14,2-32,0], p = 0,743).LIMITACIONES:La tasa de respuesta al cuestionario LARS fue sólo del 52%.CONCLUSIONES:Ampliar el periodo de espera entre radioquimioterapia y resección de 7 a 11 semanas no modifica el pronóstico oncológico a 5 años en cáncer de recto ni la baja incidencia de resección anterior a 2 años. (Traducción-Dr Osvaldo Gauto ).
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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 | 0.003 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.002 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| 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".