Study of a Screening Blood Test to Determine Patients' Potential Risk of Adenomatous or Advanced Colon Polyps (ACPs)

Peripheral Blood Telomere Length as a Biomarker of Advanced Colorectal Adenomas

The aim of this study is to develop a blood test to determine which patients are at risk for pre-cancerous colon polyps (ACPs: Advanced Colon Polyps). The telomere length of peripheral blood lymphocytes (PBLs) can be measured from a blood sample. Mechanistic pathways and the investigator's preliminary data support PBL telomere length as a biomarker for ACPs. The long-term goal of this project is to decrease deaths from colon cancer by using a blood test to target colonoscopy for those patients who are at high risk for pre-cancerous polyps.

Telomeres are the repetitive DNA sequences that cap both ends of chromosomes. Shortening of peripheral blood lymphocyte (PBL) telomeres has been associated with renal and other cancers. The investigators' preliminary data shows an association between shorter PBL telomere length and ACPs.

I. Specific Aims

1. Develop a DNA and data repository from individuals with advanced colon polyps (ACPs) and controls
2. Confirm that individuals 50 to 60 years of age with ACPs tend to have shorter peripheral blood lymphocyte (PBL) telomeres than those without ACPs
3. Identify a potential optimal PBL telomere length cut-off to differentiate between individuals with ACPs and those without for evaluation in a larger scale study

The over reaching long term goal is to decrease disease and death from colorectal cancer (CRC) using a biomarker strategy to target colonoscopy to those at higher risk.

Inclusion Criteria:

Advanced Colon Polyp Group (ACP):

• Must be 50 to 60 years of age with an advanced colon polyp (ACP: advanced colon polyps are those larger than 10 mm, or a colon polyp with high grade dysplasia, or a colon polyp with villous features.

Control Group (Controls):

• Must be 50 to 60 years of age and have had a negative screening colonoscopy.
• Controls will also have no history of adenomatous colorectal neoplasia.

Exclusion Criteria:

• Subjects under 50 years of age
• Subjects over 60 years of age
• Subjects with colon polyps less than 10 mm in size