Cancer Prevention & Control
Screening I Symptoms I Diagnosis I Staging I Treatment I Side Effects
Nutrition I Support I Future I Risks I Diet I Alcohol I Radiation
WHAT IS CANCER?
Cancer is a group of more than 100 different diseases. Cancer occurs when cells become abnormal and keep dividing and forming more cells without control or order. All organs of the body are made of cells. Normally, cells divide to produce more cells only when the body needs them. This orderly process helps keeps us healthy. If cells keep dividing when new cells are not needed, a mass of tissue forms. This mass of extra tissue, called a growth or tumor , can be benign or malignant .
Benign tumors are not cancer. They can usually be removed and, in most cases, they do not come back. Most important, cells from benign tumors do not spread to other parts of the body. Benign tumors are rarely a threat to life.
Malignant tumors are cancer. Cancer cells can invade and damage nearby tissues and organs. Also, cancer cells can break away from a malignant tumor and enter the bloodstream or the lymphatic system . This is how cancer spreads from the original (primary) tumor to form new tumors in other parts of the body. The spread of cancer is called metastasis .
Most cancers are named for the type of cell or the organ in which they begin. When cancer spreads, the new tumor has the same kind of abnormal cells and the same name as the primary tumor. For example, if lung cancer spreads to the liver, the cancer cells in the liver are lung cancer cells. The disease is called metastatic lung cancer (it is not liver cancer).
SCREENING & EARLY DETECTION
Sometimes, cancer can be found before the disease causes symptoms. Checking for cancer (or for conditions that may lead to cancer) in a person who does not have any symptoms of the disease is called screening. Screening may involve a physical exam, lab tests, and/or procedures to look at internal organs, either directly or indirectly. During a physical exam, the doctor looks for anything unusual and feels for any lumps or growths. Examples of lab tests include blood and urine tests, the Pap test (microscopic examination of cells collected from the cervix), and the fecal occult blood test (to check for hidden blood in stool). Internal organs can be seen directly through a thin lighted tube (such as a sigmoidoscope, which lets the doctor see the rectum and the lower part of the colon) or indirectly with x-ray images (such as mammograms to check the breasts).
Doctors consider many factors before recommending a screening test. They weigh factors related to the individual, the test, and the cancer that the test is intended to detect. For example, doctors take into account the person's age, medical history and general health, family history, and lifestyle. In addition, they assess the accuracy and the risks of the screening test and any follow-up tests that may be necessary. Doctors also consider the effectiveness and side effects of the treatment that will be needed if cancer is found. People may want to discuss any concerns or questions they have with their doctors, so they can weigh the pros and cons and make an informed decision about whether to have a screening test.
SYMPTOMS
You should see your doctor for regular checkups and not wait for problems to occur. But you should also know that the following symptoms may be associated with cancer: changes in bowel or bladder habits, a sore that does not heal, unusual bleeding or discharge, thickening or lump in the breast or any other part of the body, indigestion or difficulty swallowing, obvious change in a wart or mole, or nagging cough or hoarseness. These symptoms are not always a sign of cancer. They can also be caused by less serious conditions. Only a doctor can make a diagnosis. It is important to see a doctor if you have any of these symptoms. Don't wait to feel pain: Early cancer usually does not cause pain.
DIAGNOSIS
If you have a sign or symptom that might mean cancer, the doctor will do a physical exam and ask about your medical history. In addition, the doctor usually orders various tests and exams. These may include imaging procedures, which produce pictures of areas inside the body; endoscopy, which allows the doctor to look directly inside certain organs; and laboratory tests. In most cases, the doctor also orders a biopsy, a procedure in which a sample of tissue is removed. A pathologist examines the tissue under a microscope to check for cancer cells.
STAGING
When cancer is found, the patient's doctor needs to know the stage, or extent, of the disease to plan the best treatment. The doctor may order various tests and exams to find out whether the cancer has spread and, if so, what parts of the body are affected. In some cases, lymph nodes near the tumor are removed and checked for cancer cells. If cancer cells are found in the lymph nodes, it may mean that the cancer has spread to other organs.
TREATMENT
Cancer is treated with surgery, radiation therapy, chemotherapy, hormone therapy, or biological therapy. Patients with cancer are often treated by a team of specialists, which may include a medical oncologist (specialist in cancer treatment), a surgeon, a radiation oncologist (specialist in radiation therapy), and others. The doctors may decide to use one treatment method or a combination of methods. The choice of treatment depends on the type and location of the cancer, the stage of the disease, the patient's age and general health, and other factors. Some cancer patients take part in a clinical trial (research study) using new treatment methods. Such studies are designed to improve cancer treatment.
SIDE EFFECTS OF TREATMENT
It is hard to limit the effects of treatment so that only cancer cells are removed or destroyed. Because treatment also damages healthy cells and tissues, it often causes unpleasant side effects. The side effects of cancer treatment vary. They depend mainly on the type and extent of the treatment. Also, each person reacts differently. Doctors try to plan the patient's therapy to keep side effects to a minimum and they can help with any problems that occur. Surgery--The side effects of surgery depend on the location of the tumor, the type of operation, the patient's general health, and other factors. Although patients are often uncomfortable during the first few days after surgery, this pain can be controlled with medicine. Patients should feel free to discuss pain relief with the doctor or nurse. It is also common for patients to feel tired or weak for a while. The length of time it takes to recover from an operation varies for each patient. Radiation Therapy--With radiation therapy, the side effects depend on the treatment dose and the part of the body that is treated. The most common side effects are tiredness, skin reactions (such as a rash or redness) in the treated areas, and loss of appetite. Radiation therapy also may cause a decrease in the number of white blood cells, cells that help protect the body against infection. Although the side effects of radiation therapy can be unpleasant, the doctor can usually treat or control them. It also helps to know that, in most cases, they are not permanent.
Chemotherapy--
The side effects of chemotherapy depend mainly on the drugs and the doses the patient receives. Generally, anticancer drugs affect cells that divide rapidly. These include blood cells, which fight infection, help the blood to clot, or carry oxygen to all parts of the body. When blood cells are affected by anticancer drugs, patients are more likely to get infections, may bruise or bleed easily, and may have less energy. Cells that line the digestive tract also divide rapidly. As a result of chemotherapy, patients may have side effects, such as loss of appetite, nausea and vomiting, hair loss, or mouth sores. For some patients, the doctor may prescribe medicine to help with side effects, especially with nausea and vomiting. Usually, these side effects gradually go away during the recovery period or after treatment stops. Hair loss, another side effect of chemotherapy, is a major concern for many patients. Some chemotherapy drugs only cause the hair to thin out, while others may result in the loss of all body hair. Patients may feel better if they decide how to handle hair loss before starting treatment. In some men and women, chemotherapy drugs cause changes that may result in a loss of fertility (the ability to have children). Loss of fertility may be temporary or permanent depending on the drugs used and the patient's age. For men, sperm banking before treatment may be a choice. Women's menstrual periods may stop, and they may have hot flashes and vaginal dryness. Periods are more likely to return in young women.
In some cases, bone marrow transplantation and peripheral stem cell support are used to replace tissue that forms blood cells when that tissue has been destroyed by the effects of chemotherapy or radiation therapy. (See more about these procedures in the Glossary.)
Hormone Therapy--
Hormone therapy can cause a number of side effects. Patients may have nausea and vomiting, swelling or weight gain, and, in some cases, hot flashes. In women, hormone therapy also may cause interrupted menstrual periods, vaginal dryness, and, sometimes, loss of fertility. Hormone therapy in men may cause impotence, loss of sexual desire, or loss of fertility. These changes may be temporary, long lasting, or permanent.
Biological Therapy--The side effects of biological therapy depend on the type of treatment. Often, these treatments cause flu-like symptoms such as chills, fever, muscle aches, weakness, loss of appetite, nausea, vomiting, and diarrhea. Some patients get a rash, and some bleed or bruise easily. In addition, interleukin therapy can cause swelling. Depending on how severe these problems are, patients may need to stay in the hospital during treatment. These side effects are usually short-term; they gradually go away after treatment stops.
Doctors and nurses can explain the side effects of cancer treatment and help with any problems that occur. The National Cancer Institute booklets Radiation Therapy and You and Chemotherapy and You also have helpful information about cancer treatment and coping with side effects.
NUTRITION FOR CANCER PATIENTS
Some patients lose their appetite and find it hard to eat well. In addition, the common side effects of treatment, such as nausea, vomiting, or mouth sores, can make it difficult to eat. For some patients, foods tastedifferent. Also, people may not feel like eating when they are uncomfortable or tired. Eating well means getting enough calories and protein to help prevent weight loss and regain strength. Patients who eat well during cancer treatment often feel better and have more energy. In addition, they may be better able to handle the side effects of treatment. Doctors, nurses, and dietitians can offer advice for healthy eating during cancer treatment. Patients and their families also may want to read the NationalCancer Institute booklet Eating Hints for Cancer Patients, which contains many useful suggestions.
CLINICAL TRIALS
When laboratory research shows that a new treatment method has promise, cancer patients can receive the treatment in carefully controlled trials. These trials are designed to find out whether the new approach is both safe and effective and to answer scientific questions. Often, clinical trials compare a new treatment with a standard approach so that doctors can learn which is more effective. Researchers also look for ways to reduce the side effects of treatment and improve the quality of patients' lives. Patients who take part in clinical trials make an important contribution to medical science. These patients take certain risks, but they also may have the first chance to benefit from improved treatment methods.
Clinical trials offer important options for many patients. Cancer patients who are interested in taking part in a clinical trial should talk with their doctor. They may want to read Taking Part in Clinical Trials: What Cancer Patients Need To Know, a booklet that explains treatment studies and outlines some of their possible benefits and risks. One way to learn about clinical trials is through PDQ, a computerized resource developed by the National Cancer Institute. PDQ contains information about cancer treatment and about clinical trials in progress all over the country. The Cancer Information Service can provide PDQ information to doctors, patients, and the public.
SUPPORT FOR CANCER PATIENTS
Living with a serious disease is difficult. Cancer patients and those who care about them face many problems and challenges. Coping with these problems is often easier when people have helpful information and support services.
Cancer patients may worry about holding their job, caring for their family, or keeping up daily activities. Worries about tests, treatments, 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 daily activities. Meeting with a social worker, counselor, or member of the clergy also can be helpful to patients who want to talk about their feelings or discuss their concerns about the future or about personal relationships. Friends and relatives, especially those who have had personal experience with cancer, can be very supportive. Also, it helps many patients to meet with others who are facing problems like theirs. Cancer patients often get together in support groups, where they can share what they have learned about cancer and its treatment and about coping with the disease. It is important to keep in mind, however, that each patient is different. Treatments and ways of dealing with cancer that work for one person may not be right for another-- even if both have the same kind of cancer. It is always a good idea to discuss the advice of friends and family members with the doctor.
Often, a social worker at the hospital or clinic can suggest groups that help with rehabilitation, emotional support, financial aid, transportation, or home care. The American Cancer Society has many services for patients and families. Local offices of the American Cancer Society are listed in the white pages of the telephone directory.
In addition, the public library has many books and articles on living with cancer. The Cancer Information Service also has information on local resources.
WHAT THE FUTURE HOLDS
Researchers are finding better ways to detect and treat cancer, and the chance of recovery keeps improving. Still, it is natural for patients to be concerned about their future. Sometimes patients use statistics to try to figure out their chance of being cured. It is important to remember, however, that statistics are averages based on large numbers of patients. They cannot be used to predict what will happen to a particular patient because no two patients are alike. The doctor who takes care of the patient is in the best position to discuss the chance of recovery (prognosis). Patients should feel free to ask the doctor about their prognosis, but they should keep in mind that not even the doctor knows exactly what will happen. Doctors often talk about surviving cancer, or they may use the term remission rather than cure. Even though many cancer patients are cured, doctors use these terms because the disease may recur.
RISK FACTORS
Many risk factors can be avoided. Others, such as inherited risk factors, are unavoidable. It is helpful to be aware of them, but it is also important to keep in mind that not everyone with a particular risk factor for cancer actually gets the disease; in fact, most do not. People at risk can help protect themselves by avoiding risk factors where possible and by getting regular checkups so that, if cancer develops, it is likely to be found early. These are some of the factors that are known to increase the risk of cancer:
Tobacco. Tobacco causes cancer. In fact, smoking tobacco, using "smokeless" tobacco, and being regularly exposed to environmental tobacco smoke without smoking are responsible for one-third of all cancer deaths in the United States each year. Tobacco use is the most preventable cause of death in this country. Smoking accounts for more than 85 percent of all lung cancer deaths. If you smoke, your risk of getting lung cancer is affected by the number and type of cigarettes you smoke and how long you have been smoking. Overall, for those who smoke one pack a day, the chance of getting lung cancer is about 10 times greater than for nonsmokers. Smokers are also more likely than nonsmokers to develop several other types of cancer (such as oral cancer and cancers of the larynx, esophagus, pancreas, bladder, kidney, and cervix). The risk of cancer begins to decrease when a smoker quits, and the risk continues to decline gradually each year after quitting. The use of smokeless tobacco (chewing tobacco and snuff) causes cancer of the mouth and throat. Precancerous conditions, or tissue changes that may lead to cancer, begin to go away after a person stops using smokeless tobacco. Exposure to environmental tobacco smoke, also called involuntary smoking, increases the risk of lung cancer for nonsmokers. The risk goes up 30 percent or more for a nonsmoking spouse of a person who smokes. Involuntary smoking causes about 3,000 lung cancer deaths in this country each year.
If you use tobacco in any form and you need help quitting, talk with your doctor or dentist, or join a smoking cessation group sponsored by a local hospital or voluntary organization. For information on such groups or other programs, call the Cancer Information Service or the American Cancer Society.
DIET
Your choice of foods may affect your chance of developing cancer. Evidence points to a link between a high-fat diet and certain cancers, such as cancer of the breast, colon, uterus, and prostate. Being seriously overweight appears to be linked to increased rates of cancer of the prostate, pancreas, uterus, colon, and ovary, and to breast cancer in older women. On the other hand, studies suggest that foods containing fiber and certain nutrients help protect us against some types of cancer. You may be able to reduce your cancer risk by making some simple food choices. Try to have a varied, well-balanced diet that includes generous amounts of foods that are high in fiber, vitamins, and minerals. At the same time, try to cut down on fatty foods. You should eat five servings of fruits and vegetables each day, choose more whole-grain breads and cereals, and cut down on eggs, high-fat meat, high-fat dairy products (such as whole milk, butter, and most cheeses), salad dressings, margarine, and cooking oils.
Sunlight. Ultraviolet radiation from the sun and from other sources (such as sunlamps and tanning booths) damages the skin and can cause skin cancer. (Two types of ultraviolet radiation--UVA and UVB--are explained in the Medical Terms section.) Repeated exposure to ultraviolet radiation increases the risk of skin cancer, especially if you have fair skin or freckle easily. The sun's ultraviolet rays are strongest during the summer from about 11 a.m. to about 3 p.m. (daylight saving time). The risk is greatest at this time, when the sun is high overhead and shadows are short. As a rule, it is best to avoid the sun when your shadow is shorter than you are. Protective clothing, such as a hat and long sleeves, can help block the sun's harmful rays. You can also use sunscreens to help protect yourself. Sunscreens are rated in strength according to their SPF (sun protection factor), which ranges from 2 to 30 and higher. Those rated 15 to 30 block most of the sun's harmful rays.
ALCOHOL
Drinking large amounts of alcohol increases the risk of cancer of the mouth, throat, esophagus, and larynx. (People who smoke cigarettes and drink alcohol have an especially high risk of getting these cancers.) Alcohol can damage the liver and increase the risk of liver cancer. Some studies suggest that drinking alcohol also increases the risk of breast cancer. So if you drink at all, do so in moderation--not more than one or two drinks a day.
RADIATION
X-rays used for diagnosis expose you to very little radiation and the benefits nearly always outweigh the risks. However, repeated exposure can be harmful, so it is a good idea to talk with your doctor or dentist about the need for each x-ray and ask about the use of shields to protect other parts of your body. Before 1950, x-rays were used to treat non-cancerous conditions (such as an enlarged thymus, enlarged tonsils and adenoids, ringworm of the scalp, and acne) in children and young adults. People who have received radiation to the head and neck have a higher-than-average risk of developing thyroid cancer years later. People with a history of such treatments should report it to their doctor and should have a careful exam of the neck every 1 or 2 years.
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