Predictive Factors for recurrence after liver metastasectomy for colorectal Cancer

• Grant number: 11/21730-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2012
• End date: February 28, 2013
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Rachel Simões Pimenta Riechelmann
• Grantee: Carolina Satie Kita
• Host Institution: Instituto do Câncer do Estado de São Paulo Octavio Frias de Oliveira (ICESP). Coordenadoria de Serviços de Saúde (CSS). Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

One of the most important places of colorectal metastases in the liver occurs in 40-50% of the patients. Until a few years ago, the presence of liver metastatic disease was synonymous with an untreatable disease. However, surprising results have been shown by the literature, as liver metastases surgical resection has shown a 5-year survival rate of 25-55%, suggesting a curative aspect. Nevertheless, relapse after complete resection is high, occurring in 75% of resected patients in the first 2 years after surgery. There are several factors that can influence the prognosis of liver metastasis in resected patients and some may have predictive value to relapse. In this study, we are going to analyze some clinical and biological markers that have prognostic value for colorectal cancer relapse in those patients operated on for liver metastases. The primary objective study is to evaluate, through a retrospective cohort study, clinical and biological factors that may influence cancer relapse in patients with resected liver metastases from colorectal cancer. To this end, the study outcome is going to be colorectal cancer relapse in any organ, which is going to be defined by the date of the appearance of 1 or more lesions in image exams within 2 years of liver metastases surgical resection. This study is going to be a retrospective cohort of liver metastases operated on colorectal cancer patients. Patients diagnosed with liver metastases of colorectal cancer are going to be elected and the selection of the patients is going to be through an administrative list of hepatectomies performed in ICESP, thereby we are going to have to select which are the ones related to colorectal cancer metastases resection. Our data source will come from medical records of patients who underwent follow-up of colorectal cancer with liver metastases in ICESP from 2008 to 2010 until we reach a number of 100. Clinical data that could be related to a higher chance of relapse after surgery are going to be collected. In addition to the clinical information from the medical record, we are going to analyze some biomarkers in patients with available material, such as the presence or absence of mutations in codons 12 or 13 of the KRAS gene; the presence or absence of V600E mutation in B-RAF gene; the presence or absence of microsatellite instability (MSI) by immunohistochemistry for proteins encoded by 4 repair genes MSH1, MSH6, MLH1, and PMS2. Primarily a descriptive analysis of patients' characteristics is going to be done, described by proportion and median (and their respective dispersion values). The later correlative analysis is going to be done by the chi-square test to identify prognostic factors for relapse. For this study, p values less than 0,05 are going to be considered, correcting for multiple comparisons with the Bonferroni method.(AU)