Researchers at the University of Pittsburgh have enlisted at least a dozen people to take part in the study of a vaccine against colon cancer. Still in the experimental stage of development, the vaccine is expected to block the growth of pre-cancerous polyps and to prevent existing polyps from becoming cancerous. The research team expects to recruit about 50 more people during this human trials stage of study.

Estimates by the American Cancer Society suggest as many as 108,000 new diagnoses of colon cancer can be expected in the United States for 2008 and almost 41,000 cases of rectal cancer. About 50,000 deaths are expected to be attributed to the two diseases, making colorectal cancer the #3 leading cause of death by cancer in the US.

For people who are at risk of developing adenomas (polyps likely to become cancerous) or who have a history of them, the standard recommendation is to get routine colonoscopy screenings but this test is risky, inconvenient, and invasive enough that the average patient dreads it. A vaccine would eliminate these concerns as well as concerns over the risks and side effects of chemotherapy, radiation treatments, and surgery.

Adenomas in the advanced stage and those that have become cancerous produce an excessive amount of a cellular protein (MUC1). Robert E. Schoen, MD, MPH, and his research team have discovered a way to make the immune system attack and destroy this protein in much the same way a vaccine targets a virus. Schoen, a professor of medicine and epidemiology, expects this immune system response to prevent cancer progression and to stop polyps from developing.

Schoen’s co-investigator, Olivera Finn, PhD, professor of immunology at the University of Pittsburgh’s School of Medicine, says the MUC1 vaccine has already been tested on patients with pancreatic cancer and with late-stage colon cancer. In these tests, promising immune responses were achieved. Finn suggests the vaccine may prevent adenomas from becoming malignant.

Patients enrolled in the human trials must be between 40 and 70 years old and have a history of advanced adenomas. Each study participant will get one dose of vaccine upon enrollment and others at two and ten weeks into the study. Each time a vaccine dose is administered, the participant’s blood will be drawn to measure any immune response. Blood tests will continue at weeks 12, 28, and 52.