Can we attack breast cancer with a vaccine?

Teachable moment in classrooms:

1. tissues chapter – epithelial tissue lines the interior of lactiferous ducts
2. female reproductive system chapter – location of lactiferous ducts in mammary gland
3. endocrine system chapter – cells need hormone receptors to react to hormones
4. immune system – the roles of T and B lymphocytes in immune response

The news item:  The following report appeared recently:

Potential breast cancer vaccine undergoing testing

The key protein for a potential vaccine that would treat breast cancer was found through “a matter of luck and tenacity.”

The article states that a key protein was found to serve in the making of a vaccine against breast cancer. This protein is made by breast cancer cells, but not by normal mammary glands.

So, Why Do I Care??  There is over 350,000 new breast cancer diagnosis each year in the US, and over 43,000 women die yearly from this cancer. There are several types of surgical and chemotherapeutical treatments after the diagnosis, however; preventative measures, such as vaccination, would be a great way to decrease the number of breast cancer diagnoses.

Plain English, Please!!!  First, let’s talk about what breast cancer is. Despite the name, breast cancer doesn’t mean that the entire breast turned into a mass of cancer cells. Breast cancer refers to the cancerous changes in the mammary gland. Most frequently cancer cells develop in the epithelial tissues of lobules (where milk is produced) and in the lining of lactiferous ducts.

Second, let’s talk about what is a triple negative breast cancer. The normal growth of the mammary gland during pregnancy is stimulated by the hormones estrogen and progesterone, and epidermal growth factor. The hormones and the growth factor deliver their instructions through receptors. In most breast cancers the cells are positive (there is the presence of) estrogen receptor, progesterone receptor, and HER2, the receptor for epidermal growth factor. If the cells were cars, then receptors would represent the gas pedal, and estrogen, progesterone and epidermal growth factor are the foot of the driver. When a breast cancer cell doesn’t have either of those three receptors, then the cancer is called triple negative. Treatment can be more difficult, because we do not exactly know what is stimulating the aggressive growth of these cancers.

Third, let’s talk about how immunization would work against cancer. The frustration over the difficulty of the treatment of triple negative breast cancers has lead to the exploration of new treatment options. One possibility is to immunize women against molecules/antigens that the cancer cells make. One such molecule is called lactalbumin, which is not made by non-pregnant women, but made by breast cancer cells. Once vaccinated with lactalbumin, the following would happen. In the body of the vaccinated women B-lymphocytes develop into plasma cells that secrete antibodies against lactalbumin.  In addition, a group of T-lymphocytes develop (they recognize lactalbumin-making cells), and accumulate in the lymphatic organs. The vaccination trains a small group if fighters to recognize the enemy, lactalbumin-producing cell.  If triple negative breast cancer begins to develop, and the cells make lactalbumin, then the T-lymphocytes will be activated, and an army of cytotoxic T-cells will attack and destroy the cancer cells.  When the plasma cells are activated, the anti-lactalbumin antibodies would tag the dispersed cancer cells, marking them for destruction.