A cancer vaccine with a twist is making headway in clinical trials at the University of Pittsburgh School of Medicine. Rather than targeting a cancer-related virus–the way Gardasil targets human papillomavirus to prevent some cervical cancers–the new vaccine triggers the immune system to attack a faulty protein that’s often abundant in colorectal cancer tissue and precancerous tissue.
The Pitt investigators say that if the vaccine is successful, it could potentially obviate the need for repeated colonoscopies in patients at high risk for developing colorectal cancer. These patients have had multiple precancerous polyps, called advanced adenomas, in their intestines, and they are routinely screened by colonoscopy for signs of recurrence.
The vaccine has already proven safe in patients with advanced pancreatic cancer. It is now in clinical trials to gauge the immune response it elicits in patients with a history of advanced adenomas. It works by spurring the body to manufacture antibodies against the abnormal version of a mucous protein called MUC1. While moderate amounts of the protein are found in the lining of normal intestines, high levels of a defective form of MUC1 are present in about half of advanced adenomas and the majority of colorectal cancers.