By Alicia Di Rado What if doctors could help patients with advanced colon cancer to live longer-giving them more time with their loved ones and favorite activities-just by adding a common pain pill to their treatment?
That is just what oncologists are trying to do at USC/Norris, where patients with advanced colon cancer are participating in a clinical trial to test the safety and effectiveness of celecoxib, a widely prescribed medication for arthritis pain, in addition to chemotherapy in battling cancer.
Celecoxib (also known by its trade name, Celebrex) is one of a family of anti-inflammatory drugs popularly known as COX-2 inhibitors. These drugs have become popular pain relievers because they pose fewer stomach side effects than other non-steroidal anti-inflammatory drugs, or NSAIDs, such as ibuprofen and aspirin.
Research oncologist Heinz-Josef Lenz, M.D., associate professor of medicine and scientific director of cancer genetics, is leading the trial at USC/Norris. Scientists at three other major research universities are also participating in the trial.
"Celebrex is an exciting drug; not only does it help prevent colon cancer, but also increases the efficacy of chemotherapy for patients with colorectal cancer," Lenz says. "This is the first study looking at a combination of Celebrex and chemotherapy."
Here is how it works: Researchers know that COX-2 is a natural enzyme of the body involved in several diseases, including arthritis, kidney problems, osteoporosis and cancer.
Adenocarcinomas, common tumors of the colon, need COX-2 to help create blood vessels around them that keep the tumors nourished and growing (a process called angiogenesis). But COX-2 inhibitors, such as celecoxib, keep the COX-2 enzyme from working, which in turn helps keep a tumor from growing. That is why oncologists are now conducting a trial to pair celecoxib with two chemotherapy drugs (in this case, CPT-11, or irinotecan, and 5-FU, or fluorouracil) to try to starve the tumor on one front while attacking it with chemotherapy on another.
The trial involves patients whose cancer is so advanced it cannot be successfully treated with standard chemotherapy, radiation therapy or surgery.
Lenz aims to recruit 54 patients.
Lenz says it is too early to discuss results, but he is hopeful. "It has been shown in animals that COX-2 inhibition increases the efficacy of chemotherapy and radiation therapy significantly."
The U.S. Food and Drug Administration already has approved celecoxib to help reduce the number of colorectal polyps in patients with Familial
Adenomatous Polyposis (FAP), one of two known inherited roots of colon cancer. FAP causes polyps that lead to colorectal cancer if left untreated.
Oncologists in the current celecoxib trial are using the same dosage for cancer patients as that recommended preventively for FAP patients.
Other ongoing studies are testing the use of celecoxib to prevent colon cancer in families identified with the other known inherited form of colon cancer, hereditary non-polyposis colorectal cancer (HNPCC). Other sites participating in the current celecoxib trial include M.D. Anderson Cancer Center, the Robert H. Lurie Comprehensive Cancer Center of Northwestern University, and Oregon Health Sciences University.