The studied vaccine essentially causes an increase in the body’s immune cells that attack mammaglobin-A (a breast cancer-related toxin also known as MAM-A). A research team led by William Gillanders, MD (of the Washington University School of Medicine in St. Louis, Missouri) administered the vaccine to 14 patients with stable metastatic breast cancer (who had been off chemotherapy for at least 30 days) and found that they showed significant increases in the necessary immune cells with no serious side effects. This important research has shown that it is actually possible to manipulate the patient’s immune system so that it will essentially hunt down and destroy cancerous tumors.
This is the same strategy that has been used for advanced melanoma cases (and was approved by the FDA in 2013 and 2014). It is important to keep in mind, however, that this type of therapy (like all vaccine therapies) faces the challenge of how to differentiate between normal breast tissue and breast cancer cells. When you have surgery or radiation, the same principles have to be followed. You don’t want your surgeon removing normal cells, nor do you want your radiation oncologist treating normal cells. So, the challenge is in teaching the body’s immune system to leave the healthy cells alone and attack only the cancerous ones. The good news for the breast cancer vaccine, according to Dr. Gillanders, is that MAM-A is plentiful in breast cancer tissue but not in other tissues, making it a “highly attractive target”.
The vaccine is not likely to have applications in other types of cancers, since MAM-A is found almost exclusively in breast cancer cells. However, Dr. Gillanders is very optimistic about what’s ahead: “Just as HPV vaccine is being used for primary prevention of cervical cancer, a vaccine like this one may have a role in primary prevention of breast cancer.”
Clearly, the burning question is: To what extent will such a vaccine be helpful for women identified as high risk? Wouldn’t it be fantastic if women with a gene mutation such as BRCA 1 or 2 could get a vaccine to protect them from breast cancer? I am as optimistic as Dr. Gillanders, and believe that immunotherapy is the new therapeutic frontier. In the meantime, we must provide the most cutting-edge surgical, chemotherapeutic, and radiation techniques to cure the patient, while improving their experience throughout the treatment process.