New medication to prevent colon cancer

Oct 21 2004

A Stony Brook University researcher is testing a new form of aspirin--one that is much more potent than its commercially available counterpart, but with almost none of the side effects--to determine whether it can be used to prevent colon cancer in patients who are prone to the disease.

The study of the new medication--called nitric oxide-donating aspirin, or nitroaspirin--is supported by a $3.2 million grant from the National Cancer Institute. Basil Rigas, M.D., Professor of Medicine and Chief of the Division of Cancer Prevention at Stony Brook's School of Medicine, reported the findings of his trials on laboratory animals at the third annual International Conference on Frontiers in Cancer Prevention Research in Seattle. The conference was sponsored by the American Association for Cancer Research.

"Studies in cell culture and animals have shown that this new aspirin is hundreds to thousands of times more potent than traditional aspirin in inhibiting the growth of colon cancer cells and quite effective in preventing the development of colon cancer in laboratory animals," said Dr. Rigas, who will begin human trials of nitroaspirin by the end of this year.

While traditional aspirin has been shown to be effective in clinical trials in preventing certain cancers, it also is associated with significant side effects, including gastrointestinal bleeding, kidney damage, and allergic reactions ranging from mild to fatal. In addition, traditional aspirin is typically effective in preventing cancer in only about 50 per cent of those who take it.

Colon cancer can take many years to develop, but it is frequently not diagnosed in its earliest stages because cancerous lesions in the colon grown slowly and often without symptoms. More than 148,000 new cases of colon cancer are diagnosed in the U.S. each year and more than 56,000 Americans die of the diseases annually, according to the American Cancer Society.

In order to arrive at a more accurate diagnosis in less time, Dr. Rigas and his colleagues are using an advanced imaging technique called magnifying endoscopy to examine the growth of the earliest recognizable lesions, known as aberrant crypt foci, or ACF. The imaging technique will be used to evaluate 240 patients they expect to enroll over the next three years.

Dr. Rigas' work focuses on the pharmacological prevention of cancers of the colon and the pancreas. His group has made key contributions to our understanding of how aspirin and aspirin-like drugs prevent colon and other cancers. He is now developing the highly promising nitroaspirin for the prevention of colon and pancreatic cancer, being supported by five NIH grants. He also pioneered the application of infrared spectroscopy to biology with emphasis on cancer, and holds several relevant patents. He is the author of over 100 peer-reviewed publications and has co-authored a textbook of Gastroenterology, which was translated into several foreign languages.

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