New Breast Cancer Vaccine Effective: Has Lactation Protein

A research team at the Cleveland Clinic has developed a novel breast cancer vaccine that uses a protein, which is found in most breast cancers. However, present in healthy women only during lactation. According to their study, published online May 30 in Nature Medicine, the vaccine has been successful in preventing breast cancer in mice.

Ritika Jaini PhD, Dr. Vincent Tuohy, and colleagues developed the vaccine using alpha-lactalbumin, a protein that is regulated in response to the hormone prolactin during lactation. Chemically, the protein is thought to possess antitumor activity but does not cause damage to healthy tissue.

Six mice that were genetically engineered to be at high risk for breast cancer were injected with either a vaccine containing the a-lactalbumin protein or one without the antigen. None of the mice who received the experimental treatment developed breast cancer, while all of the mice in the control group did.

"Thus, α-lactalbumin vaccination may provide safe and effective protection against the development of breast cancer for women in their post-childbearing, premenopausal years, when lactation is readily avoidable and risk for developing breast cancer is high," the authors write.

This is the first vaccine designed to prevent breast cancer from developing. Many other vaccines currently under investigation are designed to halt cancer only after it is advanced.

Human clinical trials of this new breast cancer vaccine could begin as early as next year, according to Dr. Tuohy, but a marketable vaccine is still at least a decade away. He predicted that one day the vaccine could be administered routinely by injection to women starting at age 40.

“We believe that this vaccine will someday be used to prevent breast cancer in adult women in the same way that vaccines have prevented many childhood diseases,” said Tuohy. “If it works in humans the way it works in mice, this will be monumental. We could eliminate breast cancer.”

Breast cancer is the most common cancer among women in the U.S., and is the second-leading cause of cancer death in women, after lung cancer. The American Cancer Society estimates more than 190,000 cases will be diagnosed this year nationwide and 40,000 women will die of the disease.