New Treatments in Breast Cancer

Similar to other forms of cancer, breast cancer is the result of cells growing rapidly in the breast tissue and forming a tumor. Breast cancer predominantly affects women, though there are cases of men being diagnosed with the disease as well. According to the Centers for Disease Control, over 300,000 women are diagnosed with breast cancer each year. While chemotherapy is typically the first line of defense against breast cancer, ongoing research and more recent studies continue to find new treatment options that can improve life expectancy.

Hormone Therapy

According to Susan G. Komen, hormone therapy “slow[s] or stop[s] the growth of the tumor by preventing cancer cells from getting the hormones they need to grow.” This treatment can only be used on patients whose breast cancer tumors are hormone receptor-positive. If a tumor tests positive for hormone reception, the patient then receives medications, such as tamoxifen or letrozole. Some medications attach to the cell’s receptors and prevent the body’s estrogen from attaching to cancer cells which allows the cells to grow and become tumors, while others lower the overall amount of estrogen in the body.

In a recent study published in the New England Journal of Medicine, researchers have found that breast cancer patients with moderate scores on the Oncotype DX Breast Recurrence test could skip chemotherapy in favor of hormone therapy and have equal results to those who received chemotherapy in addition to hormone therapy. The Oncotype DX Breast Recurrence test generates a score on each breast cancer patient between 0 and 100 as to how likely it is that the cancer will return. The score is based on 21 different genes and how they are expressed in the patient. This includes whether a gene is turned on or off and if it is over-expressed or not in the patient. Based on these answers, a score is given to the patient.

In the past, patients with scores between 0 and 10 could skip chemotherapy and receive just hormone therapy. In this study, patients with scores from 11 to 25 were split: half received just hormone therapy, and the other half received hormone therapy and chemotherapy. The patients were followed for nine years and results found that 83 percent of patients who received just hormone therapy had not had a cancer recurrence. In patients who also received chemotherapy, 84 percent had not seen a recurrence, a difference that was deemed statistically insignificant. The overall survival rate for the two groups was similarly positive – 93.9 percent for those who received only hormone therapy; 93.8 percent for those who received both.

Immunotherapy

Immunotherapy remains in its infancy when it comes to research and use. Immunotherapy is the process of using a patient’s immune system to identify and fight cancer itself. This is done by stimulating the immune system to better respond to cancer cells or by giving it components to fit the disease, such as introducing man-made proteins to fight the cancer. Recent studies suggest it may be one of the best tools for fighting cancer in the future. In a study published in Nature Medicine, Judy Perkin’s advanced metastatic breast cancer has gone into remission using a new immunotherapy approach.

The first step of the study was to determine the DNA sequence of her tumor cells. Her doctors then searched her blood for cells which had the ability to fight off her cancer. They found 11 immune cells which were able to locate and fight the four mutant proteins present in her cancer cells. Scientists extracted the immune cells and made billions of copies in the lab. The immune cells were then introduced to her body and over the course of five months they broke down two large tumors on her chest wall, as well as four tennis-ball-sized tumors on her liver.

The excitement here is that we're attacking the very mutations that are unique to that cancer… So it's about as personalized a treatment as you can imagine.

Dr. Steven RosenbergNPR

The process for fighting Perkin’s breast cancer is different than past immunotherapies. Another type of immunotherapy, CAR-T therapy, involves removing a patient’s T-cells and genetically reengineering them in the lab to be better able to recognize a patient’s cancer. While CAR-T has had some success, it works mainly in blood cancers. Until this new study, large tumors weren’t able to be targeted with immunotherapy, suggesting scientists have found a new avenue for fighting breast cancer, and possibly other forms of cancer with more research.

Despite Perkin’s success, the same treatment failed for two other breast cancer patients. While Perkin’s results are positive, researchers know there is still more work to be done before the treatment is ready for use on a broader scale.

Going Forward

Breast cancer remains one of the most common types of cancer, affecting more than 300,000 new patients each year. While chemotherapy has been used effectively in the past, new studies suggest there may be better ways to combat the disease, avoiding potentially severe or permanent side effects caused by some chemotherapy drugs like Taxotere. Immunotherapy and hormone therapy have shown signs that they alone may be able to fight off the disease with fewer side effects for patients.