Analysis of biomarkers in rectal tumors through next-generation sequencing

Abstract

Rectal cancer is currently a disease with great impact in the majority of countries. The selection of an effective course of treatment presents great difficulty in health care centers, especially due to genetic differences between patients that determine the outcome of a given treatment. Neoadjuvant chemoradiation has provided stimulating results in treatment of rectal cancer in spite of the large variation in outcome. The identification of biomarkers that could indicate for each patient the best treatment course and determine which of them still present tumoral tissue after treatment would significantly improve the quality of treatment for this type of cancer. In this project we will use a computational and high throughput sequencing approach to identify specific inter-chromosomal rearrangements in tumor samples that can be used as biomarkers to evaluate the patient's response to treatment and detect disease relapse. Tumor samples of three different types of response to treatment will be analyzed: I) samples from patients that present complete response after initial neoadjuvant treatment; II) samples from patients that did not respond to neoadjuvant treatment; III) samples from patients that, according to clinical diagnosis, did not respond to treatment, however, a further pathological diagnosis indicates that the complete response was obtained. Thus, we hope to identify biomarkers capable of indicating the type of response for each patient during treatment. The specific biomarkers can be used for a more precise diagnosis of patients that still present tumor tissue even after initial treatment and that will be directed to surgery. (AU)