General Cancer Questions
What is cancer?
The body is made up of many types of cells. These cells grow and divide in a controlled way to produce more cells as they are needed to keep the body healthy. When cells become old or damaged, they die and are replaced with new cells.
However, sometimes this orderly process goes awry. The genetic material of a cell can become damaged or changed, leading to mutations that affect normal cell growth and division. When this happens, cells do not die when they should and new cells form when the body does not need them because the growth of cells is no longer a controlled event which is the defining feature of cancer. The extra cells may form a mass of tissue called a tumor. A tumor may be benign (non-cancerous) or malignant (cancerous). Cancer cells can spread to other parts of the body through the blood and the lymphatic system which is called metastasis.
Cancer is not just one disease but many diseases. There are more than 100 different types of cancer. Most cancers are named for the organ or type of cell in which they start – for example, cancer that begins in the colon is called colon cancer; cancer that begins in the breast is called breast cancer. If the cancer spreads to another site it is still called the name of its origin – for example, breast cancer that spread to the liver is called metastatic breast cancer.
Cancer types (based on the original site of the mutated cell) can be grouped into broader categories. The main categories of cancer include:
- Carcinoma – cancer that begins in the skin or in tissues that line or cover internal organs.
- Sarcoma – cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.
- Leukemia – cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of abnormal blood cells to be produced and enter the blood.
- Lymphoma and myeloma – cancers that begin in the cells of the immune system.
- Central nervous system cancers – cancers that begin in the tissues of the brain and spinal cord.
How did I get cancer?
The reason why people develop cancer is not well understood. In most cases the cause is unknown or “idiopathic”. There are some known risk factors that contribute to cancer development, the most important of which is smoking which contains over 200 known carcinogens (materials that can cause cancer in certain people), but many are still undiscovered. We do not know why some people who are exposed to a carcinogen get cancer and others do not. The length and amount of exposure are believed to affect the chances of developing a cancer. Your genetics (genes inherited from you parents) also likely play an important role in whether an individual develops cancer. Finally, increasing evidence suggests that dietary factors, life style and nutritional status may play a role in development of certain cancers as well.
What are the different types of cancer treatments?
Which therapy is recommended to you is based on several factors, including the specific features of your cancer; your overall health; and whether the treatment is to cure your cancer, keep your cancer from spreading, or to relieve the symptoms caused by cancer.
The treatment of cancer involves one or more of the following modalities: surgery, chemotherapy, radiation therapy, hormonal therapy targeted therapy and biological therapy.
One or more of the aforementioned treatment modalities may be recommended as the most effective way of treating a cancer. Increasingly, it is common to use several treatment modalities (“multi-modality therapy”) together or in sequence with the goal of preventing a recurrence of the cancer and improve the probability of cure.
Surgery is performed for the diagnosis, staging, and treatment of cancer. Importantly, some cancers cannot be removed by surgery because they have spread beyond an area or metastasized.
For those tumors that can be removed, a surgeon will typically remove it and adjacent tissue/lymph nodes. Information obtained from surgery can contribute to the staging of the cancer, the likelihood the cancer will recur and whether other treatment modalities will be required.
Chemotherapy is a drug or combination of drugs that attack cancer cells. This modality is used by a medical oncologist/hematologist. Typically, treatment is administered through a vein, injected into a body cavity, or delivered orally in the form of a pill.
Unlike surgery or radiation therapy in which the area treated is small or localized, chemotherapy circulates in the blood to other parts of the body where the cancer cell may have spread but is not yet seen by the naked eye or it is readily apparent.
More than half of all people diagnosed with cancer receive chemotherapy to improve the likelihood of cure, alleviate symptoms and/or prolong their life enabling patients to enjoy full and productive lives. Importantly, many side effects that were 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 treatment.
Radiation therapy uses high-energy rays to damage or kill cancer cells. This modality is used by the radiation oncologist. Like surgery, radiation therapy is a local treatment directed at a specific area in the body. It is used to shrink or eradicate visible tumor or microscopic (too small to see by the naked eye) cancer cells. 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 is called brachytherapy and 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 alone or is part of the multimodality treatment plan.
Naturally occurring hormones in the body such as estrogen and testosterone may stimulate the growth and spread of breast and prostate cancer, respectively. Hormonal therapy involves drugs that block hormone production or change the way hormones work or surgical removal of an organ that secrete hormones, such as the ovaries or testicles. Hormonal therapy can be a highly effective way to treat these hormone sensitive cancers. This form of therapy attacks cancer cells throughout the body.
Targeted therapy is the latest form of cancer treatment. It is designed to treat only the cancer cells and minimize damage to normal, healthy cells. Cancer treatments that “target” cancer cells may offer the advantage of reduced treatment-related side effects and improved outcomes.
Conventional cancer treatments, such as chemotherapy and radiation therapy, cannot distinguish between cancer cells and healthy cells. Consequently, healthy cells are commonly damaged in the process of treating the cancer, which results in side effects. Chemotherapy damages rapidly dividing cells, a hallmark trait of cancer cells. In the process, healthy cells that are also rapidly dividing, such as blood cells and the cells lining the mouth and GI tract are also damaged. Radiation therapy kills some healthy cells that are in the path of the radiation or near the cancer being treated. Newer radiation therapy techniques can reduce, but not eliminate this damage. Treatment-related damage to healthy cells leads to complications of treatment, or side effects. These side effects may be severe, reducing a patient’s quality of life, compromising their ability to receive their full, prescribed treatment, and sometimes, limiting their chance for an optimal outcome from treatment.
Biological therapy is referred to by many terms, including immunologic therapy, immunotherapy, or biotherapy. Biological therapy is a type of treatment that 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), and vaccines.
Complementary medicine (CM) represents treatment that may be given concurrent or following conventional therapy such as chemotherapy. Gentle therapies such as massage, relaxation techniques and other “healing” therapies play a significant role in disease-related symptoms as part of a palliative care program. Complementary medicine is also called holistic or integrative medicine. Some patients find relief of pain, anxiety and nausea. CM is not alternative medicine which seeks to replace conventional therapy rather CM is integrated into proven conventional therapies.
Types of CM:
- Sensory therapy (based on the 5 senses): aromatherapy, music therapy, massage, therapeutic touch, Reiki, reflexology, acupuncture
- Cognitive therapy: visualization, hypnotherapy, prayer, meditation, deep breathing/relaxation, biofeedback, journaling, support groups
- Physical therapy: exercise, yoga