Celecoxib May Help Prevent Colorectal Cancer In High Risk Patients

During the past year, the study of the potential use of COX-2 (cyclooxygenase-2) inhibitors to prevent colorectal and breast cancer has come under intense scrutiny. Recent research questioned the safety of these medicines as pain relievers, which was the initial indication, as well as for chemoprevention of cancer. Now, the latest data show that COX-2 inhibitors are highly effective in preventing pre-malignant tumors of the colon, and therefore may be useful in preventing colorectal cancer among high-risk patients.

According to two studies presented today at the 97th Annual Meeting of the American Association for Cancer Research, the over-expression of the COX-2 enzyme is related to the growth and spread of colorectal tumors. COX-2 inhibitors may reduce the occurrence of the precursor, colorectal adenomas (benign tumors) in patients with a family history of the disease, as well as the development of sporadic colorectal tumors.

Celecoxib reduces sporadic colorectal adenomas: Results from the Adenoma Prevention with Celecoxib (APC) trial.: Abstract No. CP-3

Investigators from the Adenoma Prevention with Celecoxib Study (APC) enrolled 2,035 patients to a randomized, double-blind trial of the COX-2 inhibitor, celecoxib (Celebrex®), to prevent colorectal adenomas. Results of the study revealed that celecoxib significantly reduced the formation of large intestinal adenomas during a 3-year period after removal of polyps in patients at high risk of developing colorectal cancer.

Of the participants, 679 patients received a placebo, 685 patients received 200 mg of celecoxib and 671 patients received 400 mg of celecoxib, administered twice daily. The randomization of this trial took into consideration the use of low dose aspirin in 31 percent of participants. A follow-up colonoscopy was conducted in 89 percent of participants after one year and 76 percent received a follow-up colonoscopy at three years.

The incidence of one or more benign tumors during colonoscopy was 61 percent in those taking placebo; in patients taking celecoxib this percentage was reduced by 45 percent (p<0.0001). The relative risk of advanced neoplasms (tumor) with adenomas more than one centimeter in diameter or with tubulovillous or villous features (premalignant rectal polyps), severe dysplasia (abnormal growth) or invasive cancer were also drastically reduced in patients using celecoxib, with 66 percent fewer tumors in these patients (p<0.0001).

"The results of this study show that patients at risk for developing colorectal cancer have dramatically fewer pre-malignant tumors when they take celecoxib," said Monica Bertagnolli, M.D., associate professor of surgery, Harvard University, Boston, Mass.

"This work shows that drugs that inhibit COX-2 activity are important tools in developing effective preventive therapies for colorectal cancer," she said.

Chemoprevention of Colorectal Adenomas With Celecoxib in an International Randomized, Placebo-Controlled, Double-Blind Trial: Abstract No. CP-3