By Lisa Lowry, MSN, Clinical Coordinator, Mid-Illinois Hematology and Oncology Associates
At the 2015 ASCO (American Society of Clinical Oncology) Convention, immunotherapy was one of the major themes discussed. Immunotherapy is a type of cancer treatment that stimulates one’s own immune system to fight cancer. The immune system has the ability to differentiate between healthy cells and non-healthy cells; however, cancer cells have the ability to escape the immune system by using a number of tricks. The study of immunotherapy is based on further understanding of these tricks and learning how to reverse them. Immunotherapy is different than any other standard treatment because it focuses on activating the immune system to allow the body’s immune cells to find and destroy the cancer.
Although recent breakthroughs have launched immunotherapy into the spotlight, including being named the breakthrough of the year in 2013 by Science, it has actually been studied for over a century. It began most notably with Dr. William B. Coley, who researched the effect of bacterial infections on tumors by injecting patients’ inoperable tumors with bacteria known as Coley’s Toxins. His results showed that many tumors shrank or even disappeared. The body’s immune response to the bacteria seemed to also fight the cancer.
This early research has evolved into the identification of specific tumor characteristics that help to predict if the immune system will be able to respond to a targeted therapy. The characteristics that are currently being researched and used in cancer treatment are the presence of tumor-infiltrating immune cells, gene expression patterns in tumors, and cell surface protein expression. One of the surface protein expressions is PD-L1, which has the ability to inhibit T-cell function, or an immune response, when expressed. Research is focusing on how to block the PD-L1 pathway in order to allow the immune system cells to continue in the fight against cancer.
Immunotherapy for cancer treatment has exploded in popularity in recent years with its use expanding from treatment for melanoma to other cancers, such as breast, bladder, lymphoma, lung and GI malignancies. The use of these agents has shown that it can be successful in reducing recurrence and progression rates significantly, while also decreasing the rates of metastatic disease and death. Immunotherapies are also providing options to elderly patients who may not be able to tolerate standard chemotherapy treatments.
Several different immunotherapy strategies are currently being studied or used as cancer treatment:
- Monoclonal antibodies (mAbs) are man-made versions of antibodies normally made in the body. These mAbs are created to target specific proteins found on the surface of cancer cells. This allows the immune system to find the cancer that may otherwise be able to hide from the immune cells. This type of immunotherapy destroys the tumor cells in a more efficient manner while sparing normal tissue, leading to fewer side effects from the drug.
- Non-specific immune stimulation gives the immune system a general boost to improve overall function, without targeting cancer cells specifically.
- Cancer vaccinations are vaccines created from modified viruses or from the patient’s own tumor, or from immune cells taken from the body. They are then engineered in a lab to lead the body’s immune response directly to the cancer.
- Immune-checkpoint inhibitors focus on the immune checkpoints, which are the immune system’s “brakes.” This type of treatment shuts off the brakes to keep the immune response going longer in the fight against the cancer.
- Adoptive T-cell transfer (T-cell therapy) involves removing immune cells from the patient, preparing them outside the body to fight the cancer, and then injecting them back into the patient.
Today, researchers continue to learn about how the immune system reacts to cancer, allowing them to develop different immunotherapy strategies that have shown promise in the treatment of several cancer types. Many clinical trials are taking place to help determine the efficacy of the use of immunotherapy in a variety of malignancies. The ASCO convention discussed many of the new drugs that are being studied and those that have proven to be successful in the fight against cancer. To learn more about these exciting changes you can visit www.am.asco.org/daily-news to read articles on all the new and evolving cancer treatments.
Lisa is the clinical coordinator and nurse educator at Mid-Illinois Hematology and Oncology Associates. For more information, you may contact the practice at 309-452-9701 or online at www.mihoaonline.org. They are a QOPI Certified practice located inside the Community Cancer Center at 407 E. Vernon Avenue in Normal.
Photo credit: monkeybusinessimages/iStock