Risks of colorectal neoplasms and cardiovascular thromboembolic events after the combined use of selective COX-2 inhibitors and aspirin with 5-year follow-up: a meta-analysis.
Levels of COX-2 mRNA are found over-expressed in almost 80% of the colorectal tumors, compared to paired adjacent normal colorectal mucosa, suggesting a role of COX-2 as a potential biomarker for cancer risk, whereas inhibitors of COX-2 could be of value in chemoprevention of colon cancer.
In addition, COX-2 up-regulation represents a pivotal cellular adaptive response to hypoxia with implication for colorectal tumor cell survival and angiogenesis.
In addition, overexpression of COX-2 was found more frequently in colorectal tumors with lymphatic invasion, regional lymph node metastasis and larger size, although without statistical significance.
We propose that COX2 expression in colorectal tumors is modulated by functional factors that favor high expression and by the CpG island methylator phenotype that favors silencing in a subset of cases.
We analyzed and compared expression of the inducible COX-2 isoform in colorectal neoplasms from patients with hereditary nonpolyposis colorectal cancer (HNPCC), familial adenomatous polyposis (FAP), and sporadic CRC.