For decades, researchers have studied immunotherapy—the prevention or treatment of disease through stimulation of the immune system’s response—as a treatment method for cancer patients. And last year Science magazine chose cancer immunotherapy as “Breakthrough of the Year,” reporting that years of collaborative research efforts have begun to show signs of success.
Here is more information about immunotherapy treatments and what current research may mean for people living with different types of cancer.
How cancer affects the body
To understand cancer treatments and the mechanisms by which they work, it is t important to comprehend how cancer originates and spreads throughout the body. The term “cancer” refers to more than 100 different types of diseases, in which cancer cells divide uncontrollably and invade tissues of normal cells. Cancer cells can also spread to various parts of the body—or metastasize—by moving through the bloodstream.
Where does cancer come from?
Throughout the human body, healthy cells are continually growing and dividing. They die when they become old or damaged and are then replaced by new cells. Sometimes the division of cells can result in genetic mutations. Known causes of cancer include genetic factors, lifestyle behavior and environmental exposures. Mutated cells continue to multiply when the body does not need them, which may form a cancerous (malignant) or non-cancerous (benign) tumor. Traditional cancer treatment tools include chemotherapy, radiation and surgery.
Trends in death rates for all cancers: 1975-2008 | Create Infographics
The graph above shows that death rates from cancer fell between 1990 and 2008 for both male and females. It is important for researchers to keep track of numbers of new cases, deaths and survival rates over time in order to understand trends and identify areas of improvement in screening and treatment innovations and developments.
The term “chemotherapy” means “drug treatment” and refers to the more than 100 different drugs that exist to attack cancer cells. Forms of chemotherapy include injections into the bloodstream, drips (intravenous infusion) into the bloodstream, tablets and drugs in capsule form. Chemotherapy drugs work by targeting the genes inside the nucleus of cells during the cell division process in order to stop the cells from reproducing. Depending on the type and stage of a person’s cancer, a doctor will develop a unique treatment plan with one or more types of therapies. Goals of a person’s chemotherapy treatment may include the following:
- Palliative care: Alleviation of symptoms
- Stabilizing the disease: Keeping cancer the same size, or close to the same size
- Slowing the spread of the cancer
- Partial remission: Elimination of some of or most of cancer signs
- Complete remission: Elimination of all signs of cancer
Chemotherapy: Pros and cons
While chemotherapy does not result in complete remission for all cancer patients, treatments have proven successful in helping many people survive and live long, healthy lives. Chemotherapy drugs attack both normal cells and cancer cells because they are unable to tell the difference, so normal cells become damaged. The drugs mainly target areas in the body where cells are constantly dividing and growing, such as the hair, skin and digestive system. Because chemotherapy drugs attack healthy cells in the process of attacking cancerous cells, numerous side effects may occur, such as hair loss, but side effects typically subside after treatment is over.
Compared to traditional cancer treatment tools, immunotherapy is a relatively recent advancement. This type of treatment works by helping the body’s own immune system target and attack only cancer cells, rather than administering drugs that cannot distinguish between cancerous and non-cancerous cells. While the body’s immune system may try to fight cancer, it is not able to kill rapidly-dividing cancer cells on its own. There are different types of immunotherapy treatments. One type of immunotherapy treatment works by boosting the general efficacy of the immune system. Another type of treatment involves giving the immune system man-made or naturally-derived tumor specific proteins so that the immune system becomes better able to recognize and destroy tumors.
Immunotherapy: Pros and cons
Immunotherapy treatments work to fight cancer cells while leaving healthy cells unharmed, which results in fewer or no side effects when compared to chemotherapy. Another benefit of immunotherapy is that it continues to protect the body from cancer after treatment ends, whereas the protection offered by chemotherapy typically ends when treatment does. Further research, however, is needed in order to overcome the current limitations of immunotherapy.
What’s next in immunotherapy research
One of the biggest limitations of immunotherapy treatments is that they have been tested only in relatively small trials, and they have been more successful for different participants and types of cancer than they have been for others, reasons for which remain unknown. Immunotherapy is a very active area of cancer research among the international scientific community. Scientists say they hope additional studies will lead to significant developments in cancer treatment. Areas of interest include identifying biomarkers that might explain why immunotherapy works for only some people and methods for making immunotherapy treatments more effective. Other big areas in cancer immunotherapy research include types of cancer vaccines and alternate ways to boost the immune system.
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More than 1.6 million people expected to be diagnosed with cancer in the United States in 2014, according to the scientific community and recent coverage of oncology.