Colorectal cancer associated circulating nucleic acid biomarkers

Abstract

The invention provides methods and reagents for diagnosing colorectal cancer that are based on the detection of biomarkers in the circulating nucleic acids from a patient to be evaluated. In some embodiments, the CNA biomarkers are polynucleotide fragments, e.g., DNA fragments, that are present at an elevated level in blood, e.g., in a serum or plasma sample, of a colorectal cancer patient in comparison to the level in blood, e.g., a serum or plasma sample, obtained from a normal individual who does not have colorectal cancer.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority benefit of U.S. provisional application No. 61 / 550,098, filed Oct. 21, 2011, which application is herein incorporated by reference for all purposes.BACKGROUND OF THE INVENTION[0002]Colorectal cancer is the third most common cancer diagnosis in the United States and the second leading cause of cancer-related deaths. Methods to detect colorectal cancer, including colonoscopy and stool tests are available, however there are drawback to these various testing methods (see, e.g., McFarland et al., Radiology 248:717-720, 2008). There is a need for efficient detection methods. This invention addresses that need.BRIEF SUMMARY OF THE INVENTION[0003]The invention is based, in part, on the discovery of circulating nucleic acids (CNA) biomarkers associated with colorectal cancer. In some embodiments, the CNA biomarkers are polynucleotide fragments, e.g., DNA fragments, that are present at an elevated level in blood, e....

AI Technical Summary

Benefits of technology

[0007]In another aspect, the present invention provides a method of diagnosing or screening for colorectal cancer in a patient. The method includes the steps of: (a) detecting, in a sample that is blood, serum or plasma from a patient, the level of at least 2, 3, 4, 5, 7, 8, 9, 10, 15, 20, 30, 40, 45, 50, 55, 60, 65, 70, 75, 80 or 81 of the cell-free DNA molecules each having a sequence falling within a different chromosomal region set forth in Table 2; and (b) correlating the level of said first and second cell-free DNAs with an increased likelihood that the patient has colorectal cancer. Preferably, the sequences of the cell-free DNA molecules are free of repetitive elements.

Problems solved by technology

Methods to detect colorectal cancer, including colonoscopy and stool tests are available, however there are drawback to these various testing methods (see, e.g., McFarland et al., Radiology 248:717-720, 2008).

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