Biologic Therapies | Bone Marrow Transplant | Chemotherapy | Hormonal Therapy | Managing Side Effects | Radiation | Surgery
Unlike chemotherapy and radiation therapy , which target the tumor itself, biologic therapies (biotherapy) focus on the body's biologic response to the tumor. Most of these therapies take advantage of the body's immune system, either directly or indirectly, to fight cancer or to lessen the side effects that may be caused by some cancer treatments. Since the 1980s, biotherapy has become an important modality for treating cancer. The agents used in this type of therapy are also known as biologic response modifiers.
In order for cancers to succeed, they must contend with the immune system, a complex network of cells and organs that work together to defend the body against hostile invaders. The most familiar intruders—bacteria, viruses, and other infectious organisms—originate from sources outside the body. Cancer cells—in many ways an even more dangerous foreign enemy—challenge the immune system from within.
The key cells involved in the immune system include the following:
Cytokines and antibodies are important to biologic therapies.
Biologic therapies repair, stimulate, or enhance the body’s response to cancer. According to the Leukemia and Lymphoma Society, the various biologic therapies do the following:
In general, the way biologic therapies modify the body's response to tumor cells can be divided into three broad classes:
Each biologic therapy has its own mechanism of action.
Biologic therapies are most commonly used either to treat selected cancers that do not or have not responded to other forms of treatment, or to treat those few tumors (eg, kidney cell, melanoma ) that appear to occasionally respond to the body’s own immune defenses. Because the mechanism of actions differ among the biologic therapies, the types of cancers they are used for varies.
The most common biologic therapies in use today include the following:
Interferon (IFN) occurs naturally in the body. First characterized in 1957, researchers discovered that IFN is produced by virally infected cells and is capable of protecting other cells from infection. IFNs were the first cytokines produced in a laboratory for use as a biologic therapy. There are three major types:
The way that these proteins exert their anti-tumor effects is unknown. It is probably through a combination of actions. Researchers have determined that interferons enhance the immune system’s ability to fight cancer cells, and act directly on these cells by slowing growth and encouraging normal cellular behavior.
Like interferons, interleukins (IL) occur naturally in the body and can be synthesized in a laboratory. Interleukins are named numerically: IL-1, IL-2, IL-3, up to IL-18. IL-2 has been the most widely studied in cancer treatment.
IL-2 stimulates the growth and activity of many cancer-killing immune cells, including NK cells and cytotoxic T cells. In addition, IL-2 enhances antibody responses. Both animal and human studies have shown that IL-2 can reverse immune deficiencies. Interestingly, studies have shown no differences in the biologic activity between naturally occurring IL-2 and IL-2 created in the lab.
Aldesleukin (Proleukin) is an IL-2 that is used to treat metastatic kidney cancer and metastatic melanoma.
Colony-stimulating factors (CSFs), also known as hematopoietic growth factors, do not affect cancer cells directly. Instead, CSFs help stimulate the production of new red blood cells, white blood cells, and platelets. This is important because many cancer treatments, like chemotherapy and radiation, can decrease the levels of blood cells, putting you at risk for infection, anemia , and bleeding problems. Stimulating blood cell production can help stimulate your immune system.
Some examples of CSFs include the following:
Monoclonal antibodies (MOABs) are laboratory-produced substances that are highly specific for a single target antigen. The process begins by injecting a mouse with cells from a specific human cancer. After the mouse has mounted an immune response (which includes producing antibodies to fight the cancer cells), its spleen is removed to obtain the antibodies. These antibodies are fused with laboratory-grown cells to create "hybrid" cells called hybridomas. These new cells can grow indefinitely and produce antibodies—MOABs—that have a predetermined specificity for the antigens associated with that cancer.
MOABs can be used in cancer treatment in a number of ways, for example:
There are a number of MOABs available. Examples include:
Adverse effects are specific to the type of biologic therapy used.
Side effects are similar for all classes of IFN. Variations are based on dosage, schedule, and type. But, the toxicity has been well established. Almost all people receiving IFN therapy report fatigue. The treatment is generally given as long-term therapy, so side effects are divided into acute (occurring early) and late or chronic (occurring as therapy progresses).
At the beginning of therapy, you will most likely experience flu-like symptoms. The symptoms may be severe in the beginning. But, in most cases, your body will adjust. Symptoms include chills 2-4 hours after injection of IFN followed by fever spikes. In addition, you may experience headaches, muscle pain, joint pain, and discomfort.
Chronic side effects tend to increase in intensity after you have been on IFN therapy for several weeks. Loss of appetite with weight loss and fatigue can be severe enough to limit the dose you are given. Other side effects include:
Severe toxicities are associated with high doses of IL-2. The range and severity of the effects is related to dose, schedule, and the simultaneous use of other cancer therapies.
The more common side effects include:
Other side effects include:
There are many medicines used to help manage the toxicities of IL-2. If you are experiencing any side effects, talk with your doctor about what therapies would work for you.
CSF therapy is generally well tolerated, and side effects are minimal. Bone pain is the only side effect commonly reported. This can usually be controlled with pain relievers. You may experience skin redness at the site of the injection.
With MOABs, allergic reaction to mouse protein is a major concern. This acute reaction can result in anaphylaxis , a severe, sometimes life-threatening, allergic reaction. This is rare, though.
More common side effects that can occur in the first 24 hours to 1 week after the therapy include:
A delayed toxicity that can occur 2-4 weeks after therapy is serum sickness. This results from circulating immune complexes (large, heavy antigen-antibody particles) being deposited into tissues. Symptoms include:
For details on the use of biologic therapies for specific cancers, see the following articles:
Bladder cancer
Brain tumors
Breast cancer
Cervical cancer
Colorectal cancer
Kidney cancer
Leukemia
Melanoma
Multiple myeloma
Non-Hodgkin's lymphoma
References:
Anaphylaxis. EBSCO Health Library website. Available at: http://www.ebscohost.com/thisTopic.php?marketID=15topicID=81. Updated September 2009. Accessed April 6, 2010.
Avastin. Med Help website. Available at: http://www.medhelp.org/drugs/Avastin/show/3557. Accessed April 6, 2010.
Biologic therapies: using the immune system to treat cancer. National Cancer Institute webite. Available at: http://cis.nci.nih.gov/fact/7_2.htm . Accessed December 2, 2002.
Campath. Med Help website. Available at: http://www.medhelp.org/drugs/Campath/show/3388. Accessed April 6, 2010.
DeVita VT, Hellman S, Rosenberg SA, eds. Cancer: Principles & Practice of Oncology. 6th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2001: 307-333.
Erbitux. Med Help website. Available at: http://www.medhelp.org/drugs/Erbitux/show/3546. Accessed April 6, 2010.
FS-9 Immunotherapy. The Leukemia and Lymphoma Society website. Available at: http://leukemia-lymphoma.org/.Accessed December 2, 2002.
Herceptin. Med Help website. Available at: http://www.medhelp.org/drugs/Herceptin/show/3237. Accessed April 6, 2010.
Interferon beta-1a. Med Help website. Available at: http://www.medhelp.org/tags/show/82545/interferon-beta-1a. Accessed April 6, 2010.
Interferon beta-1b. Med Help website. Available at: http://www.medhelp.org/tags/show/82550/interferon-beta-1b. Accessed April 6, 2010.
Interferon gamma-1b. Med Help website. Available at: http://www.medhelp.org/tags/show/121334/interferon-gamma-1b. Accessed April 6, 2010.
Otto SE. Oncology Nursing. 4th ed. St. Louis, MO: Mosby, Inc; 2001:684-730.
Rituxan. Med Help website. Available at: http://www.medhelp.org/drugs/Rituxan/show/3173. Accessed April 6, 2010.
Roferon-A. Med Help website. Available at: http://www.medhelp.org/tags/show/119298/Roferon-A. Accessed April 6, 2010.
Vectibix. Med Help website. Available at: http://www.medhelp.org/drugs/Vectibix/show/3675. Accessed April 6, 2010.
Last reviewed March 2010 by Igor Puzanov, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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