Optimum Timing for Surgery After Pre-operative Radiotherapy 6 vs 12 Weeks

Study Overview
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Brief Summary
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The aim of this study is to determine whether greater rectal cancer downstaging and regression occurs when surgery is delayed to 12 weeks after completion of radiotherapy/chemotherapy compared to 6 weeks. Hypothesis: Greater downstaging and tumour regression is observed when surgery is delayed to 12 weeks after completion of CRT compared to 6 weeks.

Official Title
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Is Greater Downstaging and Tumour Regression Observed When Surgery is Delayed to 12 Weeks After Completion of Chemoradiotherapy vs 6 Weeks?

Conditions
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Adenocarcinoma of the Rectum, Adenocarcinoma, Adenocarcinoma, Mucinous, Carcinoma, Neoplasms, Glandular and Epithelial, Neoplasms by Histologic Type, Neoplasms, Neoplasms, Cystic, Mucinous, and Serous, Colorectal Neoplasms, Intestinal Neoplasms, Gastrointestinal Neoplasms, Digestive System Neoplasms, Neoplasms by Site, Digestive System Diseases, Gastrointestinal Diseases, Intestinal Diseases, Rectal Diseases

Intervention / Treatment
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* Other: Patients who have surgery at 12 weeks after radiotherapy/chemoradiotherapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged > 18 Informed written consent Histological confirmation of adenocarcinoma of rectum Undergoing pre-operative radiotherapy/ chemotherapy Completion of pre-operative treatment Exclusion Criteria: Aged < 18 Absence of pre-operative RT/CT Medical/ psychiatric conditions that compromise the patients ability to give informed consent Contra-indications to MRI, i.e. hip prothesis, cardiac pacemaker

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Group 1<br>Patients who have surgery at 6 weeks after radiotherapy/chemoradiotherapy | |
| Experimental: Group 2<br>Patients who have surgery at 12 weeks after radiotherapy/chemoradiotherapy | Other: Patients who have surgery at 12 weeks after radiotherapy/chemoradiotherapy<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The primary endpoint will be the difference in the proportion of patients in each arm, downstaged according to T stage [on MRI]. |  | 6-12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Tumour response using SUV measurements [PET/CT], N downstaging and Tumour Regression Grade downstaging [on MRI]. |  | 3 months | 
| Difference in proportion of patients in each arm undergoing sphincter saving surgery. |  | 3 months | 
| Morbidity, 30 day mortality and CRM (circumferential resection margin) positivity. |  | 3 months | 
| An analysis will also be undertaken using multivariate and linear regression analysis to evaluate the association of ypT and ypN stage as a potential independent predictors of SUV (max) baseline and after radiotherapy (pre-surgery) in the two arms. |  | 3 months | 
| Local and distant recurrence rates. |  | 5 years | 
| Radiotherapy related toxicity rates. |  | 5 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Rectal Cancer, 6vs12, 6 vs 12, Cancer, CRM, Circumferential Resection Margin, Quality of Life, MRI, Radiology, Abdominoperineal Excision, Anterior Resection, Surgery, Pathology, Radiotherapy