Evaluation of Stool Based Markers for the Early Detection of Colorectal Cancers and Adenomas

Overview

Colon cancer is the second most common cancer in men and women. It is a disease that can be prevented if it is found early. Colonoscopy is still the best screening tool for colon cancer and the polyps that turn into colon cancer. However, due to a variety of factors, including affordability, time, and age, not all patients are able to be screened. Researchers are working on other options for early detection that are as accurate as colonoscopy. The purpose of this study if to determine if stool or blood can be used to detect colon cancers as early or earlier than colonoscopy. The researchers plan to use these samples to learn about specific proteins (also known as biomarkers) that may indicate colon polyps, colon cancer or an increased risk of developing colon cancer. In order to learn more about preventing and detecting colon and rectal cancer, we are collecting samples from subjects with cancer, adenomas, and colonoscopies who may be at risk for polyps.

In recognition of the fact that novel potential biomarkers are continually being identified and will need to be validated in a rapid, efficient and scientifically rigorous manner, the NCI has made an enormous commitment to the development of a network that will facilitate biomarker development and validation in multiple organ sites. As part of the National Cancer Institute-funded Early Detection Research Network (EDRN), the Great Lakes-New England Clinical Epidemiological Center (GLNE CEC) proposes a research study that validates potential molecular markers ("biomarkers") for the detection of precancerous and cancerous conditions and cancer risk assessment. Although examples of such biomarkers are currently in clinical use (i.e. CEA, CA-125), there are limitations to all of them. Our consortium focuses on gastrointestinal neoplasia. The goals of this phase of the proposed research are: 1. Assessment of the utility of individual stool-based, serum-based and urine-based biomarkers for discriminating between patients with adenocarcinomas, patients with adenomas, patients without adenomas and normal subjects both at normal and high risk for developing colon cancer. 2. Construction of a panel of markers from those considered in Objective 1 to discriminate, under a number of assumptions concerning prevalence and cost of misclassification, between: 1. Subjects with normal colons versus patients without adenomas, patients with adenomas and patients with cancers; 2. Subjects with normal colons, patients without adenomas and patients with adenomas, versus subjects with cancers; 3. Subjects with normal colons versus patients without and patients with adenomas versus patients with cancers. 3. Comparison of the characteristics of individual markers and panels as discriminators to those of the established current standard, fecal immunochemical test (FIT). 4. Continued support of a renewal of a bank of stool samples linked to serum, tissue, and clinical data from patients with colorectal cancer, adenomas and normal controls for validation of stool-based markers that may be developed in the future. To build our collection, we propose to collect stool, FIT, serum, plasma, and tissue samples from 1200 new subjects. Each biomarker will be analyzed individually and considered as a potential panel marker to be used for future largescale screening longitudinal trials. (This protocol previously recruited an additional 682 subjects from January 2006 to June 2010.)