PITTSBURGH, March 19 Researchers at the University of Pittsburgh School of Medicine have begun testing a vaccine that might be able to prevent colon cancer in people at high risk for developing the disease. If shown to be effective, it might spare patients the risk and inconvenience of repeated invasive surveillance tests, such as colonoscopy, that are now necessary to spot and remove precancerous polyps.
Colon cancer takes years to develop and typically starts with a polyp, which is a benign but abnormal growth in the intestinal lining, explained principal investigator Robert E. Schoen, M.D., M.P.H., professor of medicine and epidemiology at the University of Pittsburgh. Polyps that could become cancerous are called adenomas.
In a novel approach for cancer prevention, the Pitt vaccine is directed against an abnormal variant of a self-made cell protein called MUC1, which is altered and produced in excess in advanced adenomas and cancer. Vaccines currently in use to prevent cancer work via a different mechanism, specifically by blocking infection with viruses that are linked with cancer. For example, Gardasil protects against human papilloma virus associated with cervical cancer and hepatitis B vaccine protects against liver cancer.
"By stimulating an immune response against the MUC1 protein in these precancerous growths, we may be able to draw the immune system's fire to attack and destroy the abnormal cells," Dr. Schoen said. "That might not only prevent progression to cancer, but even polyp recurrence."
According to co-investigator Olivera Finn, Ph.D., professor and chair of the Department of Immunology at Pitt's School of Medicine, MUC1 vaccines have been tested for safety and immunogenicity in patients with late-stage colon cancer and pancreatic cancer.
"Patients were able to generate an immune response despite their cancer-weakened immune systems," she noted. "Patients with advanced adenomas are otherwise he
|Contact: Anita Srikameswaran|
University of Pittsburgh Schools of the Health Sciences