Millions of Americans are living with a diagnosis of cancer*. This National Cancer Institute (NCI) booklet (NIH Publication No. 06-1566) has information about this disease. You will read about possible causes, screening tests, symptoms, diagnosis, and treatment. You will also find suggestions for coping with cancer.
Researchers are learning more about what causes cancer, and how it grows and progresses. And they are looking for new and better ways to prevent, detect, and treat it. Researchers also are looking for ways to improve the quality of life for people with cancer during and after their treatment.
Normally, cells grow and divide to form new cells as the body needs them. When cells grow old, they die, and new cells take their place.
Sometimes, this orderly process goes wrong. New cells form when the body does not need them, and old cells do not die when they should. These extra cells can form a mass of tissue called a growth or tumor.
- Benign tumors are not cancer:
- Benign tumors are rarely life-threatening.
- Generally, benign tumors can be removed, and they usually do not grow back.
- Cells from benign tumors do not invade the tissues around them.
- Cells from benign tumors do not spread to other parts of the body.
- Malignant tumors are cancer:
- Malignant tumors are generally more serious than benign tumors. They may be life-threatening.
- Malignant tumors often can be removed, but sometimes they grow back.
- Cells from malignant tumors can invade and damage nearby tissues and organs.
- Cells from malignant tumors can spread (metastasize) to other parts of the body. Cancer cells spread by breaking away from the original (primary) tumor and entering the bloodstream or lymphatic system. The cells can invade other organs, forming new tumors that damage these organs. The spread of cancer is called metastasis.
Most cancers are named for where they start. For example, lung cancer starts in the lung, and breast cancer starts in the breast. Lymphoma is cancer that starts in the lymphatic system. And leukemia is cancer that starts in white blood cells (leukocytes).
When cancer spreads and forms a new tumor in another part of the body, the new tumor has the same kind of abnormal cells and the same name as the primary tumor. For example, if prostate cancer spreads to the bones, the cancer cells in the bones are actually prostate cancer cells. The disease is metastatic prostate cancer, not bone cancer. For that reason, it is treated as prostate cancer, not bone cancer. Doctors sometimes call the new tumor "distant" or metastatic disease.
Doctors often cannot explain why one person develops cancer and another does not. But research shows that certain risk factors increase the chance that a person will develop cancer. These are the most common risk factors for cancer:
- Growing older
- Ionizing radiation
- Certain chemicals and other substances
- Some viruses and bacteria
- Certain hormones
- Family history of cancer
- Poor diet, lack of physical activity, or being overweight
Many of these risk factors can be avoided. Others, such as family history, cannot be avoided. People can help protect themselves by staying away from known risk factors whenever possible.
If you think you may be at risk for cancer, you should discuss this concern with your doctor. You may want to ask about reducing your risk and about a schedule for checkups.
Over time, several factors may act together to cause normal cells to become cancerous. When thinking about your risk of getting cancer, these are some things to keep in mind:
- Not everything causes cancer.
- Cancer is not caused by an injury, such as a bump or bruise.
- Cancer is not contagious. Although being infected with certain viruses or bacteria may increase the risk of some types of cancer, no one can "catch" cancer from another person.
- Having one or more risk factors does not mean that you will get cancer. Most people who have risk factors never develop cancer.
- Some people are more sensitive than others to the known risk factors.
The sections below have more detailed information about the most common risk factors for cancer.
Growing OlderThe most important risk factor for cancer is growing older. Most cancers occur in people over the age of 65. But people of all ages, including children, can get cancer, too.
Tobacco use is the most preventable cause of death. Each year, more than 180,000 Americans die from cancer that is related to tobacco use.
Using tobacco products or regularly being around tobacco smoke (environmental or secondhand smoke) increases the risk of cancer.
Smokers are more likely than nonsmokers to develop cancer of the lung, larynx (voice box), mouth, esophagus, bladder, kidney, throat, stomach, pancreas, or cervix. They also are more likely to develop acute myeloid leukemia (cancer that starts in blood cells).
People who use smokeless tobacco (snuff or chewing tobacco) are at increased risk of cancer of the mouth.
Quitting is important for anyone who uses tobacco - even people who have used it for many years. The risk of cancer for people who quit is lower than the risk for people who continue to use tobacco. (But the risk of cancer is generally lowest among those who never used tobacco.)
Also, for people who have already had cancer, quitting may reduce the chance of getting another cancer.
There are many resources to help people stop using tobacco:
- Staff at the NCI's Smoking Quitline (1-877-44U-QUIT) and at LiveHelp (http://www.cancer.gov/livehelp) can talk with you about ways to quit smoking and about groups that help smokers who want to quit. Groups may offer counseling in person or by telephone.
- A Federal Government Web site, http://www.smokefree.gov, has an online guide to quitting smoking and a list of other resources.
- Doctors and dentists can help their patients find local programs or trained professionals who help people stop using tobacco.
- Doctors and dentists can suggest medicine or nicotine replacement therapy, such as a patch, gum, lozenge, nasal spray, or inhaler.
Ultraviolet (UV) radiation comes from the sun, sunlamps, and tanning booths. It causes early aging of the skin and skin damage that can lead to skin cancer.
Doctors encourage people of all ages to limit their time in the sun and to avoid other sources of UV radiation:
- It is best to avoid the midday sun (from mid-morning to late afternoon) whenever possible. You also should protect yourself from UV radiation reflected by sand, water, snow, and ice. UV radiation can penetrate light clothing, windshields, and windows.
- Wear long sleeves, long pants, a hat with a wide brim, and sunglasses with lenses that absorb UV.
- Use sunscreen. Sunscreen may help prevent skin cancer, especially sunscreen with a sun protection factor (SPF) of at least 15. But sunscreens cannot replace avoiding the sun and wearing clothing to protect the skin.
- Stay away from sunlamps and tanning booths. They are no safer than sunlight.
Ionizing radiation can cause cell damage that leads to cancer. This kind of radiation comes from rays that enter the Earth's atmosphere from outer space, radioactive fallout, radon gas, x-rays, and other sources.
Radioactive fallout can come from accidents at nuclear power plants or from the production, testing, or use of atomic weapons. People exposed to fallout may have an increased risk of cancer, especially leukemia and cancers of the thyroid, breast, lung, and stomach.
Radon is a radioactive gas that you cannot see, smell, or taste. It forms in soil and rocks. People who work in mines may be exposed to radon. In some parts of the country, radon is found in houses. People exposed to radon are at increased risk of lung cancer.
Medical procedures are a common source of radiation:
- Doctors use radiation (low-dose x-rays) to take pictures of the inside of the body. These pictures help to diagnose broken bones and other problems.
- Doctors use radiation therapy (high-dose radiation from large machines or from radioactive substances) to treat cancer.
The risk of cancer from low-dose x-rays is extremely small. The risk from radiation therapy is slightly higher. For both, the benefit nearly always outweighs the small risk.
You should talk with your doctor if you are concerned that you may be at risk for cancer due to radiation.
If you live in a part of the country that has radon, you may wish to test your home for high levels of the gas. The home radon test is easy to use and inexpensive. Most hardware stores sell the test kit.
You should talk with your doctor or dentist about the need for each x-ray. You should also ask about shields to protect parts of the body that are not in the picture.
Cancer patients may want to talk with their doctor about how radiation treatment could increase their risk of a second cancer later on.
Certain Chemicals and Other Substances
People who have certain jobs (such as painters, construction workers, and those in the chemical industry) have an increased risk of cancer. Many studies have shown that exposure to asbestos, benzene, benzidine, cadmium, nickel, or vinyl chloride in the workplace can cause cancer.
Follow instructions and safety tips to avoid or reduce contact with harmful substances both at work and at home. Although the risk is highest for workers with years of exposure, it makes sense to be careful at home when handling pesticides, used engine oil, paint, solvents, and other chemicals.
Some Viruses and Bacteria
Being infected with certain viruses or bacteria may increase the risk of developing cancer:
- Human papillomaviruses (HPVs): HPV infection is the main cause of cervical cancer. It also may be a risk factor for other types of cancer.
- Hepatitis B and hepatitis C viruses: Liver cancer can develop after many years of infection with hepatitis B or hepatitis C.
- Human T-cell leukemia/lymphoma virus (HTLV-1): Infection with HTLV-1 increases a person's risk of lymphoma and leukemia.
- Human immunodeficiency virus (HIV): HIV is the virus that causes AIDS. People who have HIV infection are at greater risk of cancer, such as lymphoma and a rare cancer called Kaposi sarcoma.
- Epstein-Barr virus (EBV): Infection with EBV has been linked to an increased risk of lymphoma.
- Human herpesvirus 8 (HHV8): This virus is a risk factor for Kaposi's sarcoma.
- Helicobacter pylori : This bacterium can cause stomach ulcers. It also can cause stomach cancer and lymphoma in the stomach lining.
Do not have unprotected sex or share needles. You can get an HPV infection by having sex with someone who is infected. You can get hepatitis B, hepatitis C, or HIV infection from having unprotected sex or sharing needles with someone who is infected.
You may want to consider getting the vaccine that prevents hepatitis B infection. Health care workers and others who come into contact with other people's blood should ask their doctor about this vaccine.
If you think you may be at risk for HIV or hepatitis infection, ask your doctor about being tested. These infections may not cause symptoms, but blood tests can show whether the virus is present. If so, the doctor may suggest treatment. Also, the doctor can tell you how to avoid infecting other people.
If you have stomach problems, see a doctor. Infection with H. pylori can be detected and treated.
Doctors may recommend hormones (estrogen alone or estrogen along with progestin) to help control problems (such as hot flashes, vaginal dryness, and thinning bones) that may occur during menopause. However, studies show that menopausal hormone therapy can cause serious side effects. Hormones may increase the risk of breast cancer, heart attack, stroke, or blood clots.
A woman considering menopausal hormone therapy should discuss the possible risks and benefits with her doctor.
Diethylstilbestrol (DES), a form of estrogen, was given to some pregnant women in the United States between about 1940 and 1971. Women who took DES during pregnancy may have a slightly higher risk of developing breast cancer. Their daughters have an increased risk of developing a rare type of cancer of the cervix. The possible effects on their sons are under study.
Women who believe they took DES and daughters who may have been exposed to DES before birth should talk with their doctor about having checkups.
Family History of Cancer
Most cancers develop because of changes (mutations) in genes. A normal cell may become a cancer cell after a series of gene changes occur. Tobacco use, certain viruses, or other factors in a person's lifestyle or environment can cause such changes in certain types of cells.
Some gene changes that increase the risk of cancer are passed from parent to child. These changes are present at birth in all cells of the body.
It is uncommon for cancer to run in a family. However, certain types of cancer do occur more often in some families than in the rest of the population. For example, melanoma and cancers of the breast, ovary, prostate, and colon sometimes run in families. Several cases of the same cancer type in a family may be linked to inherited gene changes, which may increase the chance of developing cancers. However, environmental factors may also be involved. Most of the time, multiple cases of cancer in a family are just a matter of chance.
If you think you may have a pattern of a certain type of cancer in your family, you may want to talk to your doctor. Your doctor may suggest ways to try to reduce your risk of cancer. Your doctor also may suggest exams that can detect cancer early.
You may want to ask your doctor about genetic testing. These tests can check for certain inherited gene changes that increase the chance of developing cancer. But inheriting a gene change does not mean that you will definitely develop cancer. It means that you have an increased chance of developing the disease.
Having more than two drinks each day for many years may increase the chance of developing cancers of the mouth, throat, esophagus, larynx, liver, and breast. The risk increases with the amount of alcohol that a person drinks. For most of these cancers, the risk is higher for a drinker who uses tobacco.
Doctors advise people who drink to do so in moderation. Drinking in moderation means no more than one drink per day for women and no more than two drinks per day for men.
Poor Diet, Lack of Physical Activity, or Being Overweight
People who have a poor diet, do not have enough physical activity, or are overweight may be at increased risk of several types of cancer. For example, studies suggest that people whose diet is high in fat have an increased risk of cancers of the colon, uterus, and prostate. Lack of physical activity and being overweight are risk factors for cancers of the breast, colon, esophagus, kidney, and uterus.
Having a healthy diet, being physically active, and maintaining a healthy weight may help reduce cancer risk. Doctors suggest the following:
- Eat well: A healthy diet includes plenty of foods that are high in fiber, vitamins, and minerals. This includes whole-grain breads and cereals and 5 to 9 servings of fruits and vegetables every day. Also, a healthy diet means limiting foods high in fat (such as butter, whole milk, fried foods, and red meat).
- Be active and maintain a healthy weight: Physical activity can help control your weight and reduce body fat. Most scientists agree that it is a good idea for an adult to have moderate physical activity (such as brisk walking) for at least 30 minutes on 5 or more days each week.
Some types of cancer can be found before they cause symptoms. Checking for cancer (or for conditions that may lead to cancer) in people who have no symptoms is called screening.
Screening can help doctors find and treat some types of cancer early. Generally, cancer treatment is more effective when the disease is found early.
Screening tests are used widely to check for cancers of the breast, cervix, colon, and rectum:
- Breast: A mammogram is the best tool doctors have to find breast cancer early. A mammogram is a picture of the breast made with x-rays. The NCI recommends that women in their forties and older have mammograms every 1 to 2 years. Women who are at higher-than-average risk of breast cancer should talk with their health care provider about whether to have mammograms before age 40 and how often to have them.
- Cervix: The Pap test (sometimes called Pap smear) is used to check cells from the cervix. The doctor scrapes a sample of cells from the cervix. A lab checks the cells for cancer or changes that may lead to cancer (including changes caused by human papillomavirus, the most important risk factor for cancer of the cervix). Women should begin having Pap tests 3 years after they begin having sexual intercourse, or when they reach age 21 (whichever comes first). Most women should have a Pap test at least once every 3 years.
- Colon and rectum: A number of screening tests are used to detect polyps (growths), cancer, or other problems in the colon and rectum. People aged 50 and older should be screened. People who have a higher-than-average risk of cancer of the colon or rectum should talk with their doctor about whether to have screening tests before age 50 and how often to have them.
- Fecal occult blood test: Sometimes cancer or polyps bleed. This test can detect tiny amounts of blood in the stool.
- Sigmoidoscopy: The doctor checks inside the rectum and lower part of the colon with a lighted tube called a sigmoidoscope. The doctor can usually remove polyps through the tube.
- Colonoscopy: The doctor examines inside the rectum and entire colon using a long, lighted tube called a colonoscope. The doctor can usually remove polyps through the tube.
- Double-contrast barium enema: This procedure involves several x-rays of the colon and rectum. The patient is given an enema with a barium solution, and air is pumped into the rectum. The barium and air improve the x-ray images of the colon and rectum.
- Digital rectal exam: A rectal exam is often part of a routine physical exam. The health care provider inserts a lubricated, gloved finger into the rectum to feel for abnormal areas. A digital rectal exam allows for examination of only the lowest part of the rectum.
You may have heard about other tests to check for cancer in other parts of the body. At this time, we do not know whether routine screening with these other tests saves lives. The NCI is supporting research to learn more about screening for cancers of the breast, cervix, colon, lung, ovary, prostate, and skin. See "The Promise of Cancer Research" section.
Doctors consider many factors before they suggest a screening test. They weigh factors related to the test and to the cancer that the test can detect. They also pay special attention to a person's risk for developing certain types of cancer. For example, doctors think about the person's age, medical history, general health, family history, and lifestyle. They consider how accurate the test is. In addition, doctors keep in mind the possible harms of the screening test itself. They also look at the risk of follow-up tests or surgery that the person might need to see if an abnormal test result means cancer. Doctors also think about the risks and benefits of treatment if testing finds cancer. They consider how well the treatment works and what side effects it causes.
You may want to talk with your doctor about the possible benefits and harms of being checked for cancer. The decision to be screened, like many other medical decisions, is a personal one. Each person should decide after learning about the pros and cons of screening.
The NCI has several fact sheets about screening tests.
You may want to ask the doctor the following questions about screening:
- Which tests do you recommend for me? Why?
- How much do the tests cost? Will my health insurance help pay for screening tests?
- Do the tests hurt? Are there any risks?
- How soon after the tests will I learn the results?
- If the results show a problem, how will you learn if I have cancer?
Cancer can cause many different symptoms. These are some of them:
- A thickening or lump in the breast or any other part of the body
- A new mole or a change in an existing mole
- A sore that does not heal
- Hoarseness or a cough that does not go away
- Changes in bowel or bladder habits
- Discomfort after eating
- A hard time swallowing
- Weight gain or loss with no known reason
- Unusual bleeding or discharge
- Feeling weak or very tired
Most often, these symptoms are not due to cancer. They may also be caused by benign tumors or other problems. Only a doctor can tell for sure. Anyone with these symptoms or other changes in health should see a doctor to diagnose and treat problems as early as possible.
Usually, early cancer does not cause pain. If you have symptoms, do not wait to feel pain before seeing a doctor.
If you have a symptom or your screening test result suggests cancer, the doctor must find out whether it is due to cancer or to some other cause. The doctor may ask about your personal and family medical history and do a physical exam. The doctor also may order lab tests, x-rays, or other tests or procedures.
Tests of the blood, urine, or other fluids can help doctors make a diagnosis. These tests can show how well an organ (such as the kidney) is doing its job. Also, high amounts of some substances may be a sign of cancer. These substances are often called tumor markers. However, abnormal lab results are not a sure sign of cancer. Doctors cannot rely on lab tests alone to diagnose cancer.
The NCI offers several fact sheets about lab tests.
Imaging procedures create pictures of areas inside your body that help the doctor see whether a tumor is present. These pictures can be made in several ways:
- X-rays: X-rays are the most common way to view organs and bones inside the body.
- CT scan: An x-ray machine linked to a computer takes a series of detailed pictures of your organs. You may receive a contrast material (such as dye) to make these pictures easier to read.
- Radionuclide scan: You receive an injection of a small amount of radioactive material. It flows through your bloodstream and collects in certain bones or organs. A machine called a scanner detects and measures the radioactivity. The scanner creates pictures of bones or organs on a computer screen or on film. Your body gets rid of the radioactive substance quickly.
- Ultrasound: An ultrasound device sends out sound waves that people cannot hear. The waves bounce off tissues inside your body like an echo. A computer uses these echoes to create a picture called a sonogram.
- MRI: A strong magnet linked to a computer is used to make detailed pictures of areas in your body. Your doctor can view these pictures on a monitor and can print them on film.
- PET scan: You receive an injection of a small amount of radioactive material. A machine makes pictures that show chemical activities in the body. Cancer cells sometimes show up as areas of high activity.
In most cases, doctors need to do a biopsy to make a diagnosis of cancer. For a biopsy, the doctor removes a sample of tissue and sends it to a lab. A pathologist looks at the tissue under a microscope. The sample may be removed in several ways:
- With a needle: The doctor uses a needle to withdraw tissue or fluid.
- With an endoscope: The doctor uses a thin, lighted tube (an endoscope) to look at areas inside the body. The doctor can remove tissue or cells through the tube.
- With surgery: Surgery may be excisional or incisional.
- In an excisional biopsy, the surgeon removes the entire tumor. Often some of the normal tissue around the tumor also is removed.
- In an incisional biopsy, the surgeon removes just part of the tumor.
|The pathologist uses a microscope to look at tissue.|
You may want to ask the doctor these questions before having a biopsy:
- Where will I go for the biopsy?
- How long will it take? Will I be awake? Will it hurt?
- Are there any risks? What are the chances of infection or bleeding after the procedure?
- How soon will I know the results?
- If I do have cancer, who will talk to me about the next steps? When?
To plan the best treatment for cancer, the doctor needs to know the extent (stage) of your disease. For most cancers (such as breast, lung, prostate, or colon cancer), the stage is based on the size of the tumor and whether the cancer has spread to lymph nodes or other parts of the body. The doctor may order x-rays, lab tests, and other tests or procedures to learn the extent of the disease.
Many people with cancer want to take an active part in making decisions about their medical care. It is natural to want to learn all you can about your disease and treatment choices. However, shock and stress after the diagnosis can make it hard to think of everything you want to ask the doctor. It often helps to make a list of questions before an appointment.
To help remember what the doctor says, you may take notes or ask whether you may use a tape recorder. Some people also want to have a family member or friend with them when they talk to the doctor - to take part in the discussion, to take notes, or just to listen.
You do not need to ask all your questions at once. You will have other chances to ask the doctor or nurse to explain things that are not clear and to ask for more information.
Getting a Second Opinion
Before starting treatment, you may want a second opinion about your diagnosis and treatment plan. Many insurance companies will cover a second opinion if your doctor requests it. It may take some time and effort to gather medical records and arrange to see another doctor. Usually it is not a problem to take several weeks to get a second opinion. In most cases, the delay in starting treatment will not make treatment less effective. But some people with cancer need treatment right away. To make sure, you should discuss this delay with your doctor.
There are a number of ways to find a doctor for a second opinion:
- Your doctor may refer you to one or more specialists. At cancer centers, several specialists often work together as a team.
- NCI's Cancer Information Service, at 1-800-4-CANCER, can tell you about nearby treatment centers. Information Specialists also can provide online assistance through LiveHelp (https://livehelp.cancer.gov).
- A local or state medical society, a nearby hospital, or a medical school can usually provide the names of specialists.
- The NCI provides a fact sheet called "How To Find a Doctor or Treatment Facility If You Have Cancer."
The treatment plan depends mainly on the type of cancer and the stage of the disease.
Doctors also consider the patient's age and general health. Often, the goal of treatment is to cure the cancer. In other cases, the goal is to control the disease or to reduce symptoms for as long as possible. The treatment plan may change over time.
Most treatment plans include surgery, radiation therapy, or chemotherapy. Some involve hormone therapy or biological therapy. In addition, stem cell transplantation may be used so that a patient can receive very high doses of chemotherapy or radiation therapy.
Some cancers respond best to a single type of treatment. Others may respond best to a combination of treatments.
- Local therapy removes or destroys cancer in just one part of the body. Surgery to remove a tumor is local therapy. Radiation to shrink or destroy a tumor also is usually local therapy.
- Systemic therapy sends drugs or substances through the bloodstream to destroy cancer cells all over the body. It kills or slows the growth of cancer cells that may have spread beyond the original tumor. Chemotherapy, hormone therapy, and biological therapy are usually systemic therapy.
Your doctor can describe your treatment choices and the expected results. You and your doctor can work together to decide on a treatment plan that is best for you.
Because cancer treatments often damage healthy cells and tissues, side effects are common. Side effects depend mainly on the type and extent of the treatment. Side effects may not be the same for each person, and they may change from one treatment session to the next.
Before treatment starts, the health care team will explain possible side effects and suggest ways to help you manage them. This team may include nurses, a dietitian, a physical therapist, and others. The NCI provides booklets about cancer treatments and coping with side effects. These include Radiation Therapy and You, Chemotherapy and You, Biological Therapy, and Eating Hints.
At any stage of cancer, supportive care is available to relieve the side effects of therapy, to control pain and other symptoms, and to ease emotional and practical problems. Information about supportive care is available on NCI's Web site at http://www.cancer.gov/cancertopics/coping and from Information Specialists at 1-800-4-CANCER.
You may want to talk to the doctor about taking part in a clinical trial (a research study of new treatment methods). The section on "The Promise of Cancer Research" has more information about clinical trials.
You may want to ask the doctor these questions before treatment begins:
- What is my diagnosis?
- Has the cancer spread? If so, where? What is the stage of the disease?
- What is the goal of treatment? What are my treatment choices? Which do you recommend for me? Why?
- What are the expected benefits of each kind of treatment?
- What are the risks and possible side effects of each treatment? How can side effects be managed?
- Will infertility be a side effect of my treatment? Can anything be done about that? Should I consider storing sperm or eggs?
- What can I do to prepare for treatment?
- How often will I have treatments? How long will my treatment last?
- Will I have to change my normal activities? If so, for how long?
- What is the treatment likely to cost? Will my insurance cover the costs?
- What new treatments are under study? Would a clinical trial be appropriate for me?
In most cases, the surgeon removes the tumor and some tissue around it. Removing nearby tissue may help prevent the tumor from growing back. The surgeon may also remove some nearby lymph nodes.
The side effects of surgery depend mainly on the size and location of the tumor, and the type of operation. It takes time to heal after surgery. The time needed to recover is different for each type of surgery. It is also different for each person. It is common to feel tired or weak for a while.
Most people are uncomfortable for the first few days after surgery. However, medicine can help control the pain. Before surgery, you should discuss the plan for pain relief with the doctor or nurse. The doctor can adjust the plan if you need more pain relief.
Some people worry that having surgery (or even a biopsy) for cancer will spread the disease. This seldom happens. Surgeons use special methods and take many steps to prevent cancer cells from spreading. For example, if they must remove tissue from more than one area, they use different tools for each one. This approach helps reduce the chance that cancer cells will spread to healthy tissue.
Similarly, some people worry that exposing cancer to air during surgery will cause the disease to spread. This is not true. Air does not make cancer spread.
Radiation therapy (also called radiotherapy) uses high-energy rays to kill cancer cells. Doctors use several types of radiation therapy. Some people receive a combination of treatments:
- External radiation: The radiation comes from a large machine outside the body. Most people go to a hospital or clinic for treatment 5 days a week for several weeks.
- Internal radiation (implant radiation or brachytherapy): The radiation comes from radioactive material placed in seeds, needles, or thin plastic tubes that are put in or near the tissue. The patient usually stays in the hospital. The implants generally remain in place for several days.
- Systemic radiation: The radiation comes from liquid or capsules containing radioactive material that travels throughout the body. The patient swallows the liquid or capsules or receives an injection. This type of radiation therapy can be used to treat cancer or control pain from cancer that has spread to the bone. Only a few types of cancer are currently treated in this way.
The side effects of radiation therapy depend mainly on the dose and type of radiation you receive and the part of your body that is treated. For example, radiation to your abdomen can cause nausea, vomiting, and diarrhea. Your skin in the treated area may become red, dry, and tender. You also may lose your hair in the treated area.
You may become very tired during radiation therapy, especially in the later weeks of treatment. Resting is important, but doctors usually advise patients to try to stay as active as they can.
Fortunately, most side effects go away in time. In the meantime, there are ways to reduce discomfort. If you have a side effect that is especially severe, the doctor may suggest a break in your treatment.
Chemotherapy is the use of drugs that kill cancer cells. Most patients receive chemotherapy by mouth or through a vein. Either way, the drugs enter the bloodstream and can affect cancer cells all over the body.
Chemotherapy is usually given in cycles. People receive treatment for one or more days. Then they have a recovery period of several days or weeks before the next treatment session.
Most people have their treatment in an outpatient part of the hospital, at the doctor's office, or at home. Some may need to stay in the hospital during chemotherapy.
Side effects depend mainly on the specific drugs and the dose. The drugs affect cancer cells and other cells that divide rapidly:
- Blood cells: When drugs damage healthy blood cells, you are more likely to get infections, to bruise or bleed easily, and to feel very weak and tired.
- Cells in hair roots: Chemotherapy can cause hair loss. Your hair will grow back, but it may be somewhat different in color and texture.
- Cells that line the digestive tract: Chemotherapy can cause poor appetite, nausea and vomiting, diarrhea, or mouth and lip sores.
Some drugs can affect fertility. Women may be unable to become pregnant, and men may not be able to father a child.
Although the side effects of chemotherapy can be distressing, most of them are temporary. Your doctor can usually treat or control them.
Some cancers need hormones to grow. Hormone therapy keeps cancer cells from getting or using the hormones they need. It is systemic therapy.
Hormone therapy uses drugs or surgery:
- Drugs: The doctor gives medicine that stops the production of certain hormones or prevents the hormones from working.
- Surgery: The surgeon removes organs (such as the ovaries or testicles) that make hormones.
The side effects of hormone therapy depend on the type of therapy. They include weight gain, hot flashes, nausea, and changes in fertility. In women, hormone therapy may make menstrual periods stop or become irregular and may cause vaginal dryness. In men, hormone therapy may cause impotence, loss of sexual desire, and breast growth or tenderness.
Biological therapy is another type of systemic therapy. It helps the immune system (the body's natural defense system) fight cancer. For example, certain patients with bladder cancer receive BCG solution after surgery. The doctor uses a catheter to put the solution in the bladder. The solution contains live, weakened bacteria that stimulate the immune system to kill cancer cells. BCG can cause side effects. It can irritate the bladder. Some people may have nausea, a low-grade fever, or chills.
Most other types of biological therapy are given through a vein. The biological therapy travels through the bloodstream. Some people get a rash where the therapy is injected. Some have flu-like symptoms such as fever, chills, headache, muscle aches, fatigue, weakness, and nausea. Biological therapy also can cause more serious side effects, such as changes in blood pressure and breathing problems. Biological therapy is usually given at the doctor's office, clinic, or hospital.
Stem Cell Transplantation
Transplantation of blood-forming stem cells enables patients to receive high doses of chemotherapy, radiation, or both. The high doses destroy both cancer cells and normal blood cells in the bone marrow. After the treatment, the patient receives healthy, blood-forming stem cells through a flexible tube placed in a large vein. New blood cells develop from the transplanted stem cells. Stem cells may be taken from the patient before the high-dose treatment, or they may come from another person. Patients stay in the hospital for this treatment.
The side effects of high-dose therapy and stem cell transplantation include infection and bleeding. In addition, graft-versus-host disease (GVHD) may occur in people who receive stem cells from a donor. In GVHD, the donated stem cells attack the patient's tissues. Most often, GVHD affects the liver, skin, or digestive tract. GVHD can be severe or even fatal. It can occur any time after the transplant, even years later. Drugs may help prevent, treat, or control GVHD.
The NCI offers a fact sheet called "Bone Marrow Transplantation and Peripheral Blood Stem Cell Transplantation."
Complementary and Alternative Medicine
Some people with cancer use complementary and alternative medicine (CAM):
- An approach is generally called complementary medicine when it is used along with standard treatment.
- An approach is called alternative medicine when it is used instead of standard treatment.
Acupuncture, massage therapy, herbal products, vitamins or special diets, visualization, meditation, and spiritual healing are types of CAM.
Many people say that CAM helps them feel better. However, some types of CAM may change the way standard treatment works. These changes could be harmful. Other types of CAM could be harmful even if used alone.
Some types of CAM are expensive. Health insurance may not cover the cost.
The NCI offers a booklet called Thinking About Complementary and Alternative Medicine.
You also may find materials from the National Center for Complementary and Alternative Medicine, another part of the National Institutes of Health. You can reach the NCCAM Clearinghouse toll-free at 1-888-644-6226 (voice) and 1-866-464-3615 (TTY). In addition, you can visit the Center's Website at http://www.nccam.nih.gov, or send an email to firstname.lastname@example.org.
You may want to ask the doctor these questions before you decide to use CAM:
- What benefits can I expect from this therapy?
- What are its risks?
- Do the expected benefits outweigh the risks?
- What side effects should I watch for?
- Will the therapy change the way my cancer treatment works? Could this be harmful?
- Is this therapy under study in a clinical trial? If so, who sponsors the trial?
- Will my health insurance pay for this therapy?
Nutrition and Physical Activity
It is important for people with cancer to take care of themselves. Taking care of yourself includes eating well and staying as active as you can.
You need enough calories to maintain a good weight. You also need enough protein to keep up your strength. Eating well may help you feel better and have more energy.
Sometimes, especially during or soon after treatment, you may not feel like eating. You may be uncomfortable or tired. You may find that foods do not taste as good as they used to. In addition, the side effects of treatment (such as poor appetite, nausea, vomiting, or mouth sores) can be a problem. The doctor, dietitian, or other health care provider can suggest ways to eat well. Also, the NCI booklet Eating Hints has many useful ideas and recipes.
Many people find they feel better when they stay active. Walking, yoga, swimming, and other activities can keep you strong and increase your energy. Exercise may reduce nausea and pain and make treatment easier to handle. It also can help relieve stress. Whatever physical activity you choose, be sure to talk to your doctor before you start. Also, if your activity causes you pain or other problems, be sure to let your doctor or nurse know about it.
Advances in early detection and treatment mean that many people with cancer are cured. But doctors can never be certain that the cancer will not come back. Undetected cancer cells can remain in the body after treatment. Although the cancer seems to be completely removed or destroyed, it can return. Doctors call this a recurrence.
To find out whether the cancer has returned, your doctor may do a physical exam and order lab tests, x-rays, and other tests. If you have a recurrence, you and your doctor will decide on new treatment goals and a new treatment plan.
During follow-up exams, the doctor also checks for other problems, such as side effects from cancer therapy that can arise long after treatment. Checkups help ensure that changes in health are noted and treated if needed. Between scheduled visits, you should contact the doctor if any health problems occur.
Facing Forward: Life After Cancer Treatment is an NCI booklet for people who have completed their treatment. It answers questions about follow-up care and other concerns. It has tips for making the best use of medical visits. It also suggests ways to talk with the doctor about creating a plan of action for recovery and future health.
Sources of Support
Living with a serious disease such as cancer is not easy. You may worry about caring for your family, keeping your job, or continuing daily activities. Concerns about treatments and managing side effects, hospital stays, and medical bills are also common. Doctors, nurses, and other members of the health care team can answer questions about treatment, working, or other activities. Often, a social worker can suggest resources for financial aid, transportation, home care, or emotional support. Meeting with a social worker, counselor, or member of the clergy can be helpful if you want to talk about your feelings or concerns.
Friends and relatives can be very supportive. Also, many people find it helps to talk with others who have cancer. People with cancer often get together in support groups. In these groups, patients or their family members meet with other patients or their families to share what they have learned about coping with the disease and the effects of treatment. Groups may offer support in person, over the telephone, or on the Internet. It is important to keep in mind, however, that everyone is different. Ways that one person deals with cancer may not be right for another. You may want to ask a member of your health care team about advice from other cancer patients.
Information Specialists at 1-800-4-CANCER and at LiveHelp (https://livehelp.cancer.gov) can help you locate programs, services, and publications. Also, you may want to see NCI's list of organizations that offer support services.
The Promise of Cancer Research
Researchers all over the world are looking for new and better ways to prevent, detect, diagnose, and treat cancer. They are learning more about what causes cancer. They are conducting many types of clinical trials.
A clinical trial is one of the final stages of a long and careful research process. The search for new treatments begins in the lab. If an approach seems promising in the lab, the next step is to see how the treatment affects cancer in animals and whether it has harmful effects. Of course, treatments that work well in the lab or in animals do not always work well in people. Clinical trials are needed to find out whether new approaches to cancer prevention, detection, diagnosis, and treatment are safe and effective.
Clinical trials contribute to knowledge and progress against cancer. Research already has led to many advances, and scientists continue to search for more effective approaches. Because of progress made through clinical trials, many people treated for cancer are living longer. Many of these cancer survivors also have a better quality of life compared to survivors in the past.
There are several types of clinical trials:
- Prevention trials: These studies look at whether certain substances (such as vitamins or drugs), diet changes, or lifestyle changes can lower the risk of cancer.
- Screening trials: These studies test methods of finding cancer before a person has any symptoms. Researchers study lab tests and imaging procedures that may detect specific types of cancer.
- Treatment trials: Treatment studies look at new treatments and new combinations of existing treatments. Examples include the study of drugs that kill cancer cells in new ways, new methods of surgery or radiation therapy, and new approaches such as vaccines.
- Quality of life (supportive care) trials: Scientists study ways to improve the comfort and quality of life of people with cancer. For example, doctors may study drugs that reduce the side effects of chemotherapy. Or they may explore ways to prevent weight loss or control pain.
People who join clinical trials may be among the first to benefit if a new approach turns out to be effective. And even if participants do not benefit directly, they still make an important contribution by helping doctors learn more about cancer and how to prevent, detect, and control it. Although clinical trials may pose some risks, researchers do all they can to protect their patients.
People who are interested in being part of a clinical trial should talk with their doctor. They may want to read the NCI booklet Taking Part in Cancer Treatment Research Studies. It explains how clinical trials are carried out and explains their possible benefits and risks.
At http://www.cancer.gov/clinicaltrials, NCI provides general information about clinical trials as well as detailed information about specific ongoing trials. Information Specialists at 1-800-4-CANCER and at LiveHelp (https://livehelp.cancer.gov) can answer questions and provide information about clinical trials.
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