Understanding Cancer Treatment
Medically reviewed by Dr. C.H Weaver M. Medical Editor (08/2018)
Choice of cancer treatment is influenced by several factors, including the specific characteristics of your cancer; your overall condition; and whether the goal of treatment is to cure your cancer, keep your cancer from spreading, or to relieve the symptoms caused by cancer.
Following your diagnosis of cancer, your reaction may be one of shock and disbelief. If you have been told that chemotherapy or radiation therapy are an important part of your treatment, many unpleasant images may come to mind. But as you move beyond that initial shock to begin the journey of surviving your cancer, you have many good reasons to be optimistic. Medicine has made—and continues to make—great strides in treating cancer and in making cancer treatment more tolerable, both physically and emotionally. The greatest recent advances are in Precision Medicine.
Precision cancer medicine utilizes molecular diagnostic testing, including DNA sequencing, to identify cancer-driving abnormalities in a cancer’s genome. By defining the consequences of these genetic abnormalities doctors can identify specific treatments directed against each genetic abnormality for each individual patient’s unique DNA profile.
Once a genetic abnormality is identified, a specific targeted therapy can be designed to attack a specific mutation or other cancer-related change in the DNA programming of cells. Standard chemotherapy typically destroys both normal and cancerous rapidly dividing cells in a wide range of tissues, often causing side effects by damaging normal cells. Precision cancer medicine uses targeted drugs and immunotherapies engineered to directly attack the cancer cells with specific abnormalities, leaving normal cells largely unharmed.
Depending on these factors, you may receive one or more of the following:
One or more treatment modalities may be used to provide you with the most effective treatment. Increasingly, it is common to use several treatment modalities together (concurrently) or in sequence with the goal of preventing recurrence. This is referred to as multi-modality treatment of the cancer.
Surgery is used to diagnose cancer, determine its stage, and to treat cancer. One common type of surgery that may be used to help with diagnosing cancer is a biopsy. A biopsy involves taking a tissue sample from the suspected cancer for examination by a specialist in a laboratory. A biopsy is often performed in the physician’s office or in an outpatient surgery center. A positive biopsy indicates the presence of cancer; a negative biopsy may indicate that no cancer is present in the sample.
When surgery is used for treatment, the cancer and some tissue adjacent to the cancer are typically removed. In addition to providing local treatment of the cancer, information gained during surgery is useful in predicting the likelihood of cancer recurrence and whether other treatment modalities will be necessary.
For decades researchers have sought to better understand the immune system—the elaborate network of cells and organs that protects the body from infection—and find ways of using the body’s innate disease-fighting capability to treat cancer. With cancer, part of the problem is an ineffective immune system. The immune system recognizes cancer cells as foreign and up to a point can get rid of them or keep them in check. Cancer cells however, are very good at finding ways to hide from, suppress, or wear out the immune system.
Immunotherapies stimulate or boost the immune system so that it can more effectively attack the cancer. Immunotherapy is referred to by many terms, including biologic therapy, immunologic therapy and biotherapy. Immunotherapy uses the body’s immune system to facilitate the killing of cancer cells. Types of biological therapy include interferon, interleukin, monoclonal antibodies, colony stimulating factors (cytokines), vaccines, CAR T cells, and checkpoint inhibitors.
Chemotherapy is any treatment involving the use of drugs to kill cancer cells. Cancer chemotherapy may consist of single drugs or combinations of drugs, and can be administered through a vein, injected into a body cavity, or delivered orally in the form of a pill. Chemotherapy is different from surgery or radiation therapy in that the cancer-fighting drugs circulate in the blood to parts of the body where the cancer may have spread and can kill or eliminate cancers cells at sites great distances from the original cancer. As a result, chemotherapy is considered a systemic treatment.
More than half of all people diagnosed with cancer receive chemotherapy. For millions of people who have cancers that respond well to chemotherapy, this approach helps treat their cancer effectively, enabling them to enjoy full, productive lives. Furthermore, many side effects once associated with chemotherapy are now easily prevented or controlled, allowing many people to work, travel, and participate in many of their other normal activities while receiving chemotherapy.
Radiation therapy, or radiotherapy, uses high-energy rays to damage or kill cancer cells by preventing them from growing and dividing. Similar to surgery, radiation therapy is a local treatment used to eliminate or eradicate visible tumors. Radiation therapy is not typically useful in eradicating cancer cells that have already spread to other parts of the body. Radiation therapy may be externally or internally delivered. External radiation delivers high-energy rays directly to the tumor site from a machine outside the body. Internal radiation, or brachytherapy, involves the implantation of a small amount of radioactive material in or near the cancer. Radiation may be used to cure or control cancer, or to ease some of the symptoms caused by cancer. Sometimes radiation is used with other types of cancer treatment, such as chemotherapy and surgery, and sometimes it is used alone.
Hormones are naturally occurring substances in the body that stimulate the growth of hormone sensitive tissues, such as the breast or prostate gland. When cancer arises in breast or prostate tissue, its growth and spread may be caused by the body’s own hormones. Therefore, drugs that block hormone production or change the way hormones work, and/or removal of organs that secrete hormones, such as the ovaries or testicles, are ways of fighting cancer. Hormone therapy, similar to chemotherapy, is a systemic treatment in that it may affect cancer cells throughout the body.
Clinical trials are studies that evaluate the effectiveness of new drugs or treatment strategies. The development of more effective cancer treatments requires that new and innovative therapies be evaluated with cancer patients. In oncology, clinical trials are especially important because, in the absence of high cure rates, nearly all therapeutic approaches are developmental in nature. All new cancer drugs that are currently available in the United States were once only available in clinical trials. Patients should decide whether or not participation in a clinical trial is an appropriate treatment option as early in their evaluation as possible because, once treatment of their cancer has been initiated, patients may become ineligible to participate in some clinical trials.
Stem Cell Transplant
High-dose chemotherapy (HDC) and bone marrow or blood stem cell transplantation (SCT) is the best treatment available for many kinds of cancer. The SCT procedure was developed over 40 years ago and was considered such a major development of biomedical science that the individuals responsible were awarded the Nobel Prize in Medicine in 1989. Stem cell transplant may use super high doses of chemotherapy or harness the immune system to treat the cancer.
Precision Cancer Medicine
The purpose of precision cancer medicine is to define the genomic alterations in a cancers DNA that are driving that specific cancer. Cancer used to be diagnosed solely by a visual microscopic examination of tumor tissue and all patients received the same chemotherapy. But now there is no longer a “one-size-fits-all” approach to cancer treatment. Even among patients with the same type of cancer, the behavior of the cancer and its response to treatment can vary widely. By exploring the reasons for this variation, researchers have begun to pave the way for more personalized cancer treatment.
Not all cancer cells are alike-Cancer cells may differ from one another based on what genes have mutations. Precision cancer medicine utilizes molecular diagnostic testing, including DNA sequencing, to identify cancer-driving abnormalities in a cancer’s genome. Currently this “genomic testing” is performed on a biopsy sample of the cancer. Once a genetic abnormality is identified, a specific precision cancer medicine or targeted therapy can be developed to attack a specific mutation or other cancer-related change in the DNA programming of the cancer cells. Precision cancer medicine uses targeted drugs and immunotherapies engineered to directly attack the cancer cells with specific abnormalities, leaving normal cells largely unharmed. Precision cancer medicines can be used both instead of and in addition to chemotherapy to improve treatment outcomes. Patients should ask their doctor about whether testing is appropriate.
Complementary and Integrative Medicine
Complementary medicine refers to a broad range of health practices that may be used in addition to conventional medical care. These treatments do not replace conventional cancer care and are not intended to treat cancer, but research suggests that certain types of complementary therapies may help manage symptoms and side effects and improve a person’s overall sense of well-being.
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