Salvage Abdominoperineal Resection for Anal Squamous Cell Carcinoma: Use, Risk Factors, and Outcomes in a Canadian Population
Bibliographic record
Abstract
BACKGROUND: Previous studies have reported that 30% to 40% of patients with squamous cell carcinoma of the anus will require salvage abdominoperineal resection after chemoradiotherapy. OBJECTIVE: The purpose of this study was to identify the use, risk factors, and impact on survival of salvage abdominal perineal resection for squamous cell carcinoma of the anus. DESIGN: This was a retrospective, population-based cohort study. SETTINGS: Patients treated in Ontario, Canada through a single-payer universal healthcare system, were included. PATIENTS: Patients included all incident cases of squamous cell anal cancer who underwent curative intent radiotherapy from 2007 to 2015. MAIN OUTCOME MEASURES: Risk of salvage abdominoperineal resection, factors associated with salvage abdominoperineal resection, and survival were measured. RESULTS: A total of 1125 patients were treated with curative intent radiotherapy for squamous cell cancer of the anus. Within this cohort, salvage surgery was performed in 8% (93/1125), whereas 14% (156/1125) required a permanent colostomy. In log-binomial regression, younger age was associated with salvage surgery, whereas sex, cancer stage, socioeconomic status, and HIV were not. There was a suggested lower risk of salvage surgery in those who completed chemoradiation (relative risk = 0.67 (95% CI, 0.43-1.03)). Crude 5-year overall survival rate was 73% (95% CI, 70%-76%) in those not requiring salvage surgery and 48% (95% CI, 37%-58%) in those who did. In Cox models, mortality was higher in patients requiring salvage surgery compared with those who did not (adjusted HR = 2.20 (95% CI, 1.65-2.94), whereas improved survival was seen in those who completed chemoradiation (HR = 0.65 (95% CI, 0.42-0.82)) LIMITATIONS:: The study was limited by its potential residual confounding by indication for salvage surgery. CONCLUSIONS: In this large, contemporary cohort of patients with squamous cell carcinoma of the anus, the proportion of patients undergoing salvage surgery was considerably lower than previous reports. Younger age was associated with salvage surgery, and there was a suggestion of lower risk of salvage surgery with completion of chemoradiation. Patients requiring salvage surgery had poor 5-year overall survival. See Video Abstract at http://links.lww.com/DCR/B205. RAP DE RESCATE PARA EL CARCINOMA ANAL DE CéLULAS ESCAMOSAS: USO, FACTORES DE RIESGO Y RESULTADOS EN UNA POBLACIóN CANADIENSE: Estudios anteriores han reportado que 30-40% de los pacientes con carcinoma de células escamosas del ano requerirán una resección abdominoperineal de rescate después de la quimiorradioterapia.Identificar la utilización, los factores de riesgo y el impacto en la supervivencia de la resección abdominoperineal de rescate para el carcinoma de células escamosas del ano.Estudio de cohorte retrospectivo, basado en la población.Todos los casos incidentes de cáncer anal de células escamosas que se sometieron a radioterapia con fines curativos de 2007 a 2015.Pacientes tratados en Ontario, Canadá, un sistema de salud universal de un solo pagador.Riesgo de resección abdominoperineal de rescate, factores asociados con la resección abdominoperineal de rescate y la supervivencia.1125 pacientes fueron tratados con radioterapia de intención curativa para el cáncer de células escamosas del ano. Dentro de esta cohorte, la cirugía de rescate se realizó en el 8% (93/1125), mientras que el 14% (156/1125) requirió una colostomía permanente. En la regresión log-binomial, la edad más joven se asoció con la cirugía de rescate, mientras que el sexo, la etapa del cáncer, el estado socioeconómico y el VIH no. Se sugirió un menor riesgo de cirugía de rescate en aquellos que completaron la quimiorradiación (RR 0,67; IC del 95%: 0,43 a 1,03). La tasa de supervivencia global bruta a 5 años fue del 73% (IC del 95%: 70-76%) en aquellos que no requirieron cirugía de rescate y del 48% (IC del 95%: 37-58%) en los que sí lo requirieron. En los modelos de Cox, la mortalidad fue mayor en los pacientes que requirieron cirugía de rescate en comparación con aquellos que no lo requirieron (HR ajustado 2.20, IC 95%: 1.65 - 2.94), mientras que se observó una mejor supervivencia en aquellos que completaron la quimiorradiación (HR 0.65, IC 95% 0.42 - 0,82).Posible confusión residual por indicación de cirugía de rescate.En esta gran cohorte contemporánea de pacientes con carcinoma de células escamosas del ano, la proporción de pacientes sometidos a cirugía de rescate fue considerablemente menor que los informes anteriores. La edad más temprana se asoció con la cirugía de rescate, y se sugirió un menor riesgo de cirugía de rescate con la finalización de la quimiorradiación. Los pacientes que requirieron cirugía de rescate tuvieron una deficiente supervivencia general de 5 años. Consulte Video Resumen en http://links.lww.com/DCR/B205. (Traducción-Dr Gonzalo Hagerman).
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 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 | 0.000 |
| 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".