Clinical Trial Comparing Carnoy's and GEWF Solutions for Lymph Node Clearing Technique in Colorectal Cancer

Clinical Trial Comparing Carnoy's and GEWF Solutions for Lymph Node Clearing Technique in Colorectal Cancer

Randomized Clinical Trial Comparing Carnoy's and GEWF Solutions for Lymph Node Clearing Technique in Colorectal Cancer

Regional lymph node metastasis is a major determinant of local recurrence and overall survival rates in patients with colorectal cancer. Because of the poor prognosis associated with the presence of lymph node metastasis, stage III colorectal cancer patients should receive adjuvant treatment with chemo and / or radiation therapy according to the site of tumor. Several authors have investigated the use of revealing solutions for lymph node clearance in colorectal cancer. Most studies comparing conventional histopathological specimen examination to any lymph node clearing technique showed that the use of revealing solutions increases the mean number of lymph nodes harvested, usually in a statistically significant manner. It is still controversial the impact of the use of revealing solutions for upstaging of lymph node status and consequently for the indication for adjuvant therapy. Therefore will be conducted a randomized clinical trial to compares the performance of GEWF and Carnoy solutions for the histopathological examination of patients with colorectal cancer. The aim of this study is to determine the lymph node revealing solution with the best performance (increase in the mean number of lymph node harvested and lymph node upstaging) in patients with colorectal cancer.

Patients with histologically proven colorectal adenocarcinoma submitted to curative resection and conventional histopathological examination of the surgical specimen are randomized to undergo further investigation by lymph node clearing technique with Carnoy or GEWF solution.

The subjects in this group will undergo intervention by having surgery and lymph node clearing technique. Intervention A: Carnoy solution Intervention B: GEWF solution

The subjects in this group will undergo intervention by having surgery and lymph node clearing technique. Intervention A: Carnoy solution Intervention B: GEWF solution

Procedure: lymph node clearing technique with Carnoy solution (1) just after the surgical resection each specimen is fixed by formaldehyde; (2) lymph node harvesting is performed by a manual technique of vision and palpation; (3) lymph nodes retrieved are counted, stained with hematoxylin and eosin and examined with light microscopy; (4) the surgical specimen is submitted to re-fixation with Carnoy solution and another lymph node harvesting by manual technique of vision and palpation; (5) additional lymph nodes retrieved are counted, stained with hematoxylin and eosin and examined with light microscopy.

Procedure: lymph node clearing technique with GEWF solution (1) just after the surgical resection each specimen is fixed by formaldehyde; (2) lymph node harvesting is performed by a manual technique of vision and palpation; (3) lymph nodes retrieved are counted, stained with hematoxylin and eosin and examined with light microscopy; (4) the surgical specimen is submitted to re-fixation with GEWF solution and another lymph node harvesting by manual technique of vision and palpation; (5) additional lymph nodes retrieved are counted, stained with hematoxylin and eosin and examined with light microscopy.

Diagnosis of lymph node metastasis in a patient initially classified as having no lymph node metastasis or increase in the number of metastatic lymph nodes in a patient already staged as having lymph node metastasis.

Indication of adjuvant therapy as consequence of the upstaging after the lymph nodes clearing technique.

Inclusion Criteria: Histologically proven colorectal adenocarcinoma Voluntary agreement of the patient to participate in research Voluntary agreement of the surgeon to participate in research Exclusion Criteria: Absence of accurate histopathological data