PET on Surgery for Loco-regionally Recurrent Colorectal Cancer

Study Overview
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Brief Summary
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The influence of Positron-Emission-Tomography (PET) on the surgical treatment of loco-regionally recurrent colorectal cancer (LRRCRC) remains obscure and deserves further investigation.

Detailed Description
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Loco-regionally recurrent colorectal cancer (LRRCRC) occurs in 4.0-11.5% of patients following treatment of primary colorectal cancer with curative intent, and can be categorized as peri-anastomotic, mesenteric/paracolic (nodal), retroperitoneal and peritoneal.1-4 In contrast to distant recurrences (e.g. liver, lung or bone metastasis), LRRCRCs is a less recognized clinical entity, although it is generally accepted that surgical resection remains the major treatment modality to provide the long-term survival for such patients.5-7 However, the value of resection for LRRCRC is obscure, given the role of surgical resection in treating LRRCRC has received comparatively little attention with a scant literature to draw upon when making treatment recommendations and no available consensus statements.8,9 Moreover, in clinical practice, it has been recognized that more than 50% of patients with recurrent colorectal cancer brought to the operating room for attempted curative surgery were unable to undergo the planned operation because more extensive disease than anticipated was discovered at laparotomy. Therefore, it has been suggested that a formal multidisciplinary team (MDT) discussion based on more precise diagnostic armamentariums be mandatory for more accurate evaluation of tumor burden and would allow curative surgery to be offered to a better-selected group of patients with recurrent colorectal malignancy10-14. Remarkably, Positron-Emission-Tomography (PET) scans are now being widely used for the surveillance of patients having undergone curative resection for the primary colorectal cancer . Whole-body PET scanning in the patient with recurrent colorectal cancer has been reported to be more sensitive and accurate than Computed-Tomography (CT) and Magnetic-Resonance-Imaging (MRI). Moreover, PET is purported to be capable of differentiating among recurrent malignancy, scar, fibrosis, and necrosis, thus preventing the patients from futile surgery.15 With the above-mentioned reasons in mind, we then conducted this retrospective study to look at the efficacy of PET scan for directing surgery in patients with LRRCRC. We hypothesized that with the better diagnostic sensitivity and specificity, as compared to the conventional imaging methods (CT/MRI) in detecting recurrences of colorectal cancer, PET can positively affect the surgical decision-making and thus improve the treatment outcomes for patients with LRRCRCs.

Official Title
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Impact of Positron-Emission-Tomography on the Surgical Treatment for Loco-regionally Recurrent Colorectal Cancer

Conditions
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PET-driven Surgery, Loco-regional Recurrent Colorectal Cancer

Intervention / Treatment
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* Procedure: Curative intent surgery


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: i. patients with primary colorectal cancers undergoing R0 resection ii. Patients with final histopathologic reports documenting the pathologic Tumor-Node-Metastasis (pTNM) stage I, II, or III Exclusion Criteria: i. Patients with pTNM stage IV primary colorectal cancer ii. Patients with R1/2 resection

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sole PET group<br>Tumor recurrence was detected solely by PET; the surgery was performed and the extent of the resection was guided by the PET. | Procedure: Curative intent surgery<br>* Curative intent surgery means that surgeons intend to perform R0 resection.<br>|
| Combined CT/MRI plus PET group<br>Tumor recurrence was detected by computed tomography (CT) / magnetic resonance imaging (MRI) and PET; the surgery was performed and the extent of the resection was guided by the CT/MRI+PET. | Procedure: Curative intent surgery<br>* Curative intent surgery means that surgeons intend to perform R0 resection.<br>|
| Control group<br>Tumor recurrence was detected but no surgery was performed. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 5-year overall survival | 5-year overall survival | 10 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Life expectancy | Median survival | 10 year | 
| Type of resection | Sham operation vs R0 vs R1 vs R2 | 10 year | 
| Blood loss | recorded in mL | 10 year | 
| Operation time | recorded in minute | 10 year | 
| Type of surgical complication | specific complications; Clavien-Dindo classification | 10 year | 
| Hospitalization | recorded in day | 10 year | 
| Readmission | within 30 days | 10 year |