Technologies

BACKGROUND

Colorectal cancer is the second leading cause of cancer-related deaths and the third most common cancer in the US and other Western countries. Adenomatous polyps are well-known, clear-cut histologic lesions that have been identified as precursors to colorectal cancer. Therefore, polyps are of critical importance in the early identification and potential prevention of colorectal cancer. These pre-cancerous lesions are very common in the normal population, with frequencies of 30-40% in people 60 years and older. Fortunately, they can often be removed easily and in a time/cost effective way before they develop into actual cancers.

Polyps recur in a statistically significant subset of people who undergo polypectomy. Currently, there are no predictive factors to determine who will have recurrent polyps and eventually colon cancer among polypectomy patients, although people with high-grade polyps are believed to have a worse prognosis. As a consequence, the only method presently available for the diagnosis of colon lesions and determination of their prognosis is direct examination by a pathologist. This is a very approximate and subjective approach, however, and there is a need for markers that could help clinicians decide which high-grade polyps are more likely to become colorectal cancer.

INNOVATION

Amplification of a region of human chromosome 20 is a frequent event in colon adenocarcinomas, occurring in approximately 70% of cases (or ~35%, when correction for chromosome 20 polysomy is applied). Researchers at the University of California have now found that intermediary diagnostic states of the adenoma to adenocarcinoma sequence that are thought to be the immediate precursors of adenocarcinoma, such as high-grade dysplasia and intramucosal carcinoma, also display increased copy number of this chromosomal region. Specifically, the researchers found amplifications of this region in approximately 40% (or ~30%, when correction for chromosome 20 polysomy is applied) of high-grade dysplasia lesions and intramucosal carcinomas. Methods of screening for colon carcinoma precursor cells by determining the presence of increased copy number of this region are covered by a U.S. patent assigned to the University of California (see below).