Educate Yourself About Cancer
What is Cancer?
Cancer develops when cells in a part of the body begin to grow out of control. Although there are many kinds of cancer, they all start because of out-of-control growth of abnormal cells.
Normal body cells grow, divide and die in an orderly fashion. During the early years of a person's life, normal cells divide more rapidly until the person becomes an adult. After that, cells in most parts of the body divide only to replace worn-out or dying cells and to repair injuries.
Because cancer cells continue to grow and divide, they are different from normal cells. Instead of dying, they outlive normal cells and continue to form new abnormal cells.
Cancer cells develop because of damage to DNA. This substance is in every cell and directs all its activities. Most of the time when DNA becomes damaged, either the cell dies or is able to repair the DNA. In cancer cells, the damaged DNA is not repaired. People can inherit damaged DNA, which accounts for inherited cancers. Many times though, a person’s DNA becomes damaged by exposure to something in the environment, like smoking.
Cancer usually forms as a tumor. Some cancers, like leukemia, do not form tumors. Instead, these cancer cells involve the blood and blood-forming organs and circulate through other tissues where they grow.
Cancer cells often travel to other parts of the body where they begin to grow and replace normal tissue. This process, called metastasis, occurs as the cancer cells become present in the bloodstream or lymph vessels of our body. When cells from a cancer, like breast cancer, spread to another organ like the liver, the cancer is still called breast cancer, not liver cancer.
Remember that not all tumors are cancerous. Benign (noncancerous) tumors do not spread to other parts of the body (metastasize) and, with very rare exceptions, are not life-threatening.
Different types of cancer can behave very differently. For example, lung cancer and breast cancer are very different diseases. They grow at different rates and respond to different treatments. That is why people with cancer need treatment that is aimed at their particular kind of cancer.
Cancer is the second leading cause of death in the United States. Half of all men and one-third of all women in the United States will develop cancer during their lifetimes. Today, millions of people are living with cancer or have had cancer. The risk of developing most types of cancer can be reduced by changes in a person's lifestyle, for example, by quitting smoking and eating a better diet. The sooner a cancer is found and treatment begins, the better are the chances for recovery.
Source: American Cancer Society
Diagnostic Procedures for Cancer
When symptoms suggest cancer, your physician may request/perform any of the following procedures to help positively diagnose it:
- A detailed medical history, family and personal
- Thorough physical examination
- Pelvic examination of the uterus, vagina, ovaries, bladder and rectum
- Pap test may be requested at the time of pelvic examination
Other diagnostic procedures that may be requested include:
- Imaging tests, such as:
- X-ray
- Computed tomography (CT or CAT scan) - a non-invasive procedure that takes cross-sectional images of the brain or other internal organs; detects any abnormalities that may not show up on an ordinary x-ray. The CT scan may indicate enlarged lymph nodes, a possible sign of a spreading cancer or of an infection.
- Radionuclide scan - an imaging scan in which a small amount of radioactive substance is injected into the vein. A machine measures levels of radioactivity in certain organs, thereby detecting any abnormal areas or tumors.
- Ultrasound - an imaging technique that uses sound waves to produce an image on a monitor of the abdominal organs, such as the uterus, liver and kidneys.
- Magnetic resonance imaging (MRI) - a non-invasive procedure that produces a two-dimensional view of an internal organ or structure, especially the brain and spinal cord. The MRI may show abnormal nodules in bones or lymph nodes, a sign that cancer may be spreading.
- Endoscopy - use of a very flexible tube with a lens or camera (and a light on the end), which is connected to a computer screen, allowing the physician to see inside the hollow organs, such as the uterus. Biopsy samples can be taken through the tube.
- Laboratory tests to examine any/all of the following:
- Blood
- Urine
- Other fluids
- Tumor tissue
- Biopsy (to remove a sample of the suspicious tissue for examination in a laboratory by a pathologist)
Once the cancer is diagnosed, an evaluation will be made to determine the extent (stage) of the cancer.
Grading and Staging of Cancer
After the determination is made as to the type of cancer, the cancer is graded. This is a measurement of how aggressive the tumor is. Most cancer cells are graded by how much they look like normal cells. Grading is done in the lab using cancerous cells taken during biopsy.
There are many different types of grading systems used by doctors. These vary depending on the cancer. In general, however, lower grades mean a less aggressive behavior and higher grades predict for a relatively more aggressive cancer.
Once cancer is diagnosed, more tests will be done to find out if the cancer cells have spread to other parts of the body. This testing is called staging. To plan treatment, a physician needs to know the stage of the disease. Stage refers to the extent or size of the cancer. Each cancer, by organ, has its own staging system.
Stages of cancer:
- Stage 0, or carcinoma in situ
Carcinoma in situ is very early cancer. The abnormal cells are found only in the first layer of cells of the primary site and do not invade the deeper tissues.
- Stage I
Cancer involves the primary site, but has not spread to nearby tissues.
- Stage II
Cancer has spread to nearby areas but is still inside the primary site.
- Stage III
Cancer has spread throughout the nearby area.
- Stage IV
Cancer has spread to other parts of the body.
- Recurrent
Recurrent disease means that the cancer has come back after it has been treated.
Chemotherapy
Chemotherapy (also referred to as cytotoxic therapy) is the use of anti-cancer drugs to treat cancerous cells. Chemotherapy reaches all parts of the body, not just the cancer cells. The oncologist will recommend a treatment plan for each individual. Specific treatment will be based on:
- Your overall health and medical history
- Your age and whether you are menstruating
- The type and stage of the cancer
- Your tolerance for specific medications and procedures
- Expectations for the course of the disease
- Your opinion or preference
The oncologist will also determine how long and how often you will have chemotherapy treatments. Chemotherapy can be administered intravenously or by pill and is usually a combination of drugs. Chemotherapy treatments are often given in cycles; a treatment for a period of time, followed by a recovery period, then another treatment. Chemotherapy may be given in a variety of settings including your home, a hospital outpatient facility, a physician's office or clinic, or in a hospital.
Radiation Therapy
Radiation therapy is the use of radiation to injure or destroy cancer cells. High-energy rays, including x-rays or gamma rays, may be used against the cells. Radiation is considered a regional therapy, affecting cancer cells only in the treated area of the body.
Radiation therapy is administered through several different methods:
- External radiation treatment refers to treatment to an area of the body by exposing it to a beam of x-rays or gamma rays. The rays penetrate the body from the outside and deposit energy in the tissues in its path. The rays cause injury to all cells - the normal, as well as the cancerous cells. Some are killed, some are injured and repair themselves, and some are not affected. Normal cells are injured, but are able to repair themselves better than cancer cells.
- Radiation therapy is also administered by radiation implants, called brachytherapy. The implants are placed in the cancer itself, or right next to it, and are usually left in place for several hours or several days and then removed. The implant gives off radiation to the surrounding tissue while it is in place. The amount of radiation administered is determined by the tolerance of the normal tissues that are also irradiated. Eventually, the implants are either removed or they die out.
Surgery
According to the American Cancer Society, 60 percent of people with cancer have some type of surgery. Surgery is used in cancer treatment for several purposes:
- Preventive -- to remove tissue that does not yet contain cancer cells but has the probability of becoming cancerous in the future. This may also be referred to as prophylactic surgery.
- Diagnostic -- to remove samples of tissue from a suspicious area for testing and evaluation (in a laboratory by a pathologist) to confirm a diagnosis, identify the type of cancer or determine the stage of the cancer.
- Curative -- to remove or destroy cancerous tissue, which may include removal of some tissue around the tumor and nearby lymph nodes.
Surgery may also be performed for:
- Palliative purposes -- to relieve discomfort.
- Supportive purposes -- to allow for placement of a device that will aid in the delivery of medications.
- Restorative or reconstructive purposes -- to repair or replace damaged or destroyed areas of the body.
Examples of types of surgical procedures used to diagnose or destroy cancerous tissue include:
- Biopsy - removal of sample of tissue via a hollow needle or scalpel.
- Endoscopy - use of a very flexible tube with a lens or camera (and a light on the end), which is connected to a computer screen, allowing the physician to see inside the hollow organs, such as the uterus. Biopsy samples can be taken through the tube.
- Laparoscopy - use of a viewing tube with a lens or camera (and a light on the end), which is inserted through a small incision in the abdomen to examine the contents of the abdomen and remove tissue samples.
- Laparotomy - a surgical procedure that involves an incision through the abdominal wall; often used when making a diagnosis by less invasive tests is difficult.
- Laser surgery - use of a powerful beam of light, which can be directed to specific parts of the body without making a large incision, to destroy abnormal cells.
- Cryosurgery - use of liquid nitrogen, or a probe that is very cold, to freeze and kill cancer cells.
- Electrosurgery - use of high-frequency electrical currents to destroy cancer cells.
- Excisional - cutting away cancerous tissue with a scalpel or other instruments to completely remove it and possibly some surrounding tissue. There are many types of excisional surgeries, each named for the particular area of the body in which they are performed, or the particular purpose for which they are performed.
Hormone Therapy
Some types of cancer thrive and grow because of hormones (estrogen, testosterone and progesterone) that naturally occur in the body, while other types of cancer growth is slowed or suppressed by these same types of hormones.
Hormone therapy as cancer treatment may involve:
- Removing the organ(s) that is the source of the hormone (such as the testes and ovaries).
- Taking hormones or hormone-like drugs to treat the cancer.
Researchers are continually studying the risks and benefits of hormone therapy for the treatment of gynecological cancers.
Immunotherapy/Biological Therapy
Immunotherapy (also called biological therapy, biological response modifier therapy or biotherapy) uses the body's immune system to fight cancer.
The cells, antibodies and organs of the immune system work to protect or defend the body against foreign invaders, such as bacteria or viruses. Physicians and researchers found that the immune system may also be able to determine the difference between healthy cells and cancer cells in the body, and eliminate the cancer cells.
What are the immune system cells that fight cancer and other diseases?
- Lymphocytes - white blood cells, including B cells, T cells and NK cells.
- B cells - become plasma cells that make antibodies or immunoglobulins.
- T cells - produce cytokines, which control immune response.
- NK cells - produce chemical substances that bind to and kill foreign invaders in the body.
- Monocytes - white blood cells that move into tissues and develop into macrophages, which, when needed, play a role in phagocytosis. Phagocytosis is a process in which some cells "eat" other cells or foreign invaders.
Biological response modifier (BRM) therapy
BRMs are substances that occur naturally in the body, such as cytokines or antibodies, which assist the body in fighting disease. BRMs can also be made in the laboratory. These artificially created BRMs directly inhibit tumor cell growth, as well as assist the healthy cells in controlling the cancer. They have been successfully used in combination with each other and with other treatments. Some BRMs include:
- Interferons (IFNs)
- Interleukins (ILs)
- Tumor necrosis factors (TNFs)
- Colony-stimulating factors (CSFs)
- Monoclonal antibodies (MAOBs)
- Cancer vaccines