Title: Oncology
Date: June 22, 2004
Everybody knows someone who has suffered or perhaps even died from cancer. Cancer has been described as the “plague of the 20th century” and nearly every food, beverage, drug, and activity is associated with an increased risk of one or more types of cancer.
We hear about lung cancer, breast cancer, prostate cancer, colon cancer, bone cancer, leukemia, and brain cancer. Each has been described as the principal cause of death for some narrow demographic group, and each has a screening test that should be frequently applied to members of that group.
All women should perform monthly breast self-examinations to rule out breast cancer. Frequent mammograms, pap-smears, buddy checks, blood tests and colonoscopies are cited as the best defense against an untimely death from some mysterious and sinister neoplasm. Don’t smoke. Don’t drink. Don’t take drugs. Exercise. Eat right. Stay healthy. Cancer will probably get you anyway.
I hope that you’ve caught my sarcasm.
Cancer is a serious business. All told, it will cause roughly 20% of all the deaths in the United States this year. Another 20% of the population will at some point be diagnosed with one form of cancer or another. Putting it in terms of simple probability, you have 2 chances out of 5 of being diagnosed with some type of cancer in your lifetime. If you live long enough; cancer will probably kill you. Some researchers consider cancer the natural and inevitable consequence of degeneration within the body. Others consider it an aberration, and something we can avoid.
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 the body is able to repair it. 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.
Often, cancer cells travel to other parts of the body, where they begin to grow and replace normal tissue. This process is called metastasis. Regardless of where a cancer may spread, however, it is always named for the place it began. For instance, breast cancer that spreads to the liver is still called breast cancer, not liver cancer.
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 cancer.
Cancer is the second leading cause of death in the United States. Nearly half of all men and a little over one-third of all women in the US 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 living for many years.
Who Gets Cancer?
Over one million people get cancer each year. Approximately one out of every two American men and one out of every three American women will have some type of cancer at some point during their lifetime. Anyone can get cancer at any age; however, about 77% of all cancers are diagnosed in people age of 55 and older. Although cancer occurs in Americans of all racial and ethnic groups, the rate of cancer occurrence (called the incidence rate) varies from group to group.
Today, millions of people are living with cancer or have been cured of the disease. The sooner a cancer is found and the sooner treatment begins, the better a patient's chances are of a cure. That's why early detection of cancer is such an important weapon in the fight against cancer.
What Are the Risk Factors for Cancer?
A risk factor is anything that increases a person's chance of getting a disease. Some risk factors can be changed, and others cannot. Risk factors for cancer can include a person's age, sex, and family medical history. Others are linked to cancer-causing factors in the environment. Still others are related to lifestyle choices such as tobacco and alcohol use, diet, and sun exposure.
Having a risk factor for cancer means that a person is more likely to develop the disease at some point in their lives. However, having one or more risk factors does not necessarily mean that a person will get cancer. Some people with one or more risk factors never develop the disease, while other people who do develop cancer have no apparent risk factors. Even when a person who has a risk factor is diagnosed with cancer, there is no way to prove that the risk factor actually caused the cancer.
Different kinds of cancer have different risk factors. Some of the major risk factors include the following:
Cancers of the lung, mouth, larynx, bladder, kidney, cervix esophagus, and pancreas are related to tobacco use, including cigarettes, cigars, chewing tobacco, and snuff. Smoking alone causes one-third of all cancer deaths.
Skin cancer is related to unprotected exposure to strong sunlight.
Breast cancer risk factors include several factors: age; changes in hormone levels throughout life, such as age at first menstruation, number of pregnancies, and age at menopause; obesity; and physical activity. Some studies have also shown a connection between alcohol consumption and an increased risk of breast cancer. Also, women with a mother or sister who have had breast cancer are more likely to develop the disease themselves.
While all men are at risk for prostate cancer, several factors can increase the chances of developing the disease, such as age, race, and diet. The chance of getting prostate cancer goes up with age. Prostate cancer is more common among African-American men than among white men. (We do not yet know why this is so.) A high-fat diet may play a part in causing prostate cancer. Also, men with a father or brother who have had prostate cancer are more likely to get prostate cancer themselves.
Overall, environmental factors, defined broadly to include tobacco use, diet, and infectious diseases, as well as chemicals and radiation cause an estimated 75% of all cancer cases in the United States. Among these factors, tobacco use, unhealthy diet, and physical activity are more likely to affect personal cancer risk. Research shows that about one-third of all cancer deaths are related to dietary factors and lack of physical activity in adulthood.
Certain cancers are related to viral infections and could be prevented by behavior changes or vaccines. More than 1 million skin cancers expected to be diagnosed in 2003 could have been prevented by protection from the sun's rays.
Can Cancer Be Prevented?
Smoking and drinking alcohol cause some people to get certain types of cancer. These cancers might be prevented by avoiding tobacco and alcohol. The best idea is to never use tobacco at all. Cigarettes, cigars, pipes and smokeless tobacco cause cancer and should not be used. People who already smoke should try to quit. Former smokers have less risk of cancer than do people who continue to smoke.
The chances of getting skin cancer can be lowered by staying in the shade as much as you can, wearing a hat and shirt when you are in the sun, and using sunscreen.
We know that our diet, (what we eat) is linked to some types of cancer, although the exact reasons are not yet clear. The best advice is to eat a lot of fresh fruits and vegetables and whole grains like pasta and bread, and to cut down on high fat foods.
There are tests, called screening examinations, that adults should have in order to find cancer early. If cancer is found early it can often be cured.
What Causes Cancer?
Some kinds of cancer are caused by things people do. Smoking can cause cancers of the lungs, mouth, throat, bladder, kidneys and several other organs, as well as heart disease and stroke. While not everyone who smokes will get cancer, smoking increases a person's chance of getting the disease. Drinking a lot of alcohol has also been shown to increase a person's chance of getting cancer of the mouth, throat, and some other organs. This is especially true if the person drinks and smokes.
Radiation (x-rays) can cause cancer. But the x-rays used by the doctor or dentist are safe. Too much exposure to sunlight without any protection can cause skin cancer.
In many cases, the exact cause of cancer remains a mystery. We know that certain changes in our cells can cause cancer to start, but we don't yet know exactly how this happens. Many scientists are studying this problem.
Signs and Symptoms of Cancer
What Are Symptoms and Signs?
A symptom is an indication of disease, illness, injury, or that something is not right in the body. Symptoms are felt or noticed by a person, but may not easily be noticed by anyone else. For example, chills, weakness, achiness, shortness of breath, and a cough are possible symptoms of pneumonia.
A sign is also an indication that something is not right in the body. But signs are defined as observations made by a doctor, nurse, or other health care professional. Fever, rapid breathing rate, and abnormal breathing sounds heard through a stethoscope are possible signs of pneumonia.
The presence of one symptom or sign may not give enough information to suggest a cause. For example, a rash in a child could be a symptom of a number of things including poison ivy, a generalized infection like rubella, an infection limited to the skin, or a food allergy. But if the rash is associated with a high fever, chills, achiness, and a sore throat, then all of the symptoms together give a better picture of the illness. In many cases, a patient's signs and symptoms do not provide enough clues to determine the cause of an illness, and medical tests such as x-rays, blood tests, or a biopsy may be needed.
How Does Cancer Produce Signs and Symptoms?
Cancer is a group of diseases that may cause any sign or symptom. The signs and symptoms will depend on the size of the cancer, where the cancer is, and how much it affects the surrounding organs or structures. If a cancer spreads(metastasizes), then symptoms may appear in different parts of the body.
As a cancer grows, it begins to push on nearby organs, blood vessels and nerves. This pressure creates some of the signs and symptoms of cancer. If the cancer is in a critical area, such as certain parts of the brain, even the smallest tumor can produce early symptoms.
Sometimes, however, cancers form in places where symptoms may not be produced until the cancer has grown quite large. Pancreas cancers, for example, do not usually grow large enough to be felt from the outside of the body. Some pancreatic cancers do not produce symptoms until they begin to grow around nearby nerves, causing a backache. Others grow around the bile duct, leading to a yellowing of the skin known as jaundice. Unfortunately by the time a pancreatic cancer causes these signs or symptoms, it has usually reached an advanced stage.
A cancer may also cause generalized symptoms such as fever, fatigue, or weight loss. This may be caused by cancer cells releasing substances that change the body’s metabolism. Or the cancer may cause the immune system to react in ways that produce these symptoms.
Sometimes, cancer cells release substances into the bloodstream that cause symptoms not generally thought to result from cancers. For example, some cancers of the pancreas can release substances which cause blood clots to develop in veins of the legs. Some lung cancers produce hormone-like substances that affect blood calcium levels, affecting nerves and muscles and causing weakness and dizziness.
How Are Signs and Symptoms Helpful?
Treatment is most successful when the cancer is found as early as possible. Finding cancer early usually means it can be treated while it is still small and is less likely to have spread to other parts of the body. Usually, this means a better chance for a cure, especially if initial treatment is to be surgery.
A good example of the importance of detecting cancer early is melanoma skin cancer. It is easily removed if has not yet grown deeply into the skin, and the 5-year survival rate (percentage of people living at least 5 years after diagnosis) at this stage is nearly 100%. But once melanoma has spread to other parts of the body, the survival rate drops dramatically.
Sometimes symptoms are ignored because the person is either frightened by their implications and refuses to seek medical help or does not recognize the symptom as being significant. General symptoms, such as fatigue, are more likely to have a cause other than cancer and can easily be dismissed, especially if they have an obvious cause or are only temporary. In a similar way, a person may reason that a more specific symptom like a breast mass is probably a cyst that will go away by itself. But neither of these symptoms should be discounted or overlooked, especially if they have been present for a period of time, such as weeks, or are getting worse.
In some cases it is possible to detect some cancers before symptoms occur. The American Cancer Society and other organizations encourage the early detection of certain cancers before symptoms occur by recommending a cancer-related checkup and specific early detection tests for people who do not have any symptoms. For more information on early detection tests, see our document, "Cancer Detection Guidelines." Keep in mind, however, that these recommended early detection tests do not diminish the importance of reporting any symptoms to your doctor.
General Cancer Signs and Symptoms
It is important to know what some of the general (nonspecific) signs and symptoms of cancer are. They include unexplained weight loss, fever, fatigue, pain, and changes in the skin. Of course, it’s important to remember that having any of these does not necessarily mean that cancer is present--there are many other conditions that can cause these signs and symptoms as well.
Unexplained weight loss: Most people with cancer will lose weight at some time with their disease. An unexplained (unintentional) weight loss of about 10 pounds may be the first sign of cancer, particularly cancers of the pancreas, stomach, esophagus, or lung.
Fever: Fever is very common with cancer, but is more often seen in advanced disease. Almost all patients with cancer will have fever at some time, particularly if the cancer or its treatment affects the immune system and reduces resistance to infection. Less often, fever may be an early sign of cancer, such as with Hodgkin's disease.
Fatigue: Fatigue may be a significant symptom as the cancer progresses. It may occur early, however, especially if the cancer is causing a chronic loss of blood, as in some colon or stomach cancers.
Pain: Pain may be an early sign with some cancers, such as bone cancers or testicular cancer. Most often, however, pain is a symptom of advanced disease.
Skin changes: In addition to cancers of the skin, some internal cancers can produce visible skin signs such as darkening (hyperpigmentation) yellowing (jaundice), reddening (erythema), itching, or excessive hair growth.
Specific Cancer Signs and Symptoms
In addition to the above general symptoms, you should be watchful for the following common symptoms, which could be an indication of cancer. Again, there may be other causes for each of these, but it is important to bring them to your doctor’s attention as soon as possible so that they can be investigated.
Change in bowel habits or bladder function: Chronic constipation, diarrhea, or a change in the size of the stool may indicate colon cancer. Pain with urination, blood in the urine, or a change in bladder function (such as more frequent or less frequent urination) could be related to bladder or prostate cancer. Any changes in bladder or bowel function should be reported to your doctor.
Sores that do not heal: Skin cancers may bleed and resemble sores that do not heal. A persistent sore in the mouth could be an oral cancer and should be dealt with promptly, especially in patients who smoke, chew tobacco, or frequently drink alcohol. Sores on the penis or vagina may either be signs of infection or an early cancer, and should not be overlooked in either case.
Unusual bleeding or discharge: Unusual bleeding can occur in early or advanced cancer. Blood in the sputum (phlegm) may be a sign of lung cancer. Blood in the stool (or a dark or black stool) could be a sign of colon or rectal cancer. Cancer of the cervix or the endometrium (lining of the uterus) can cause vaginal bleeding. Blood in the urine is a sign of possible bladder or kidney cancer. A bloody discharge from the nipple may be a sign of breast cancer.
Thickening or lump in breast or other parts of the body: Many cancers can be felt through the skin, particularly in the breast, testicle, lymph nodes (glands), and the soft tissues of the body. A lump or thickening may be an early or late sign of cancer. Any lump or thickening should be reported to your doctor, especially if you’ve just discovered it or noticed it has grown in size. You may be feeling a lump that is an early cancer that could be treated successfully.
Indigestion or difficulty swallowing: While they commonly have other causes, these symptoms may indicate cancer of the esophagus, stomach, or pharynx (throat).
Recent change in a wart or mole: Any change in color or shape, loss of definite borders, or an increase in size should be reported to your doctor without delay. The skin lesion may be a melanoma which, if diagnosed early, can be treated successfully.
Nagging cough or hoarseness: A cough that does not go away may be a sign of lung cancer. Hoarseness can be a sign of cancer of the larynx (voice box) or thyroid.
What Is Remission?
Remission is a period of time when the cancer is responding to treatment or is under control. In a complete remission, all the signs and symptoms of the disease disappear. It is also possible for a patient to have a partial remission in which the cancer shrinks but does not completely disappear. Remissions can last anywhere from several weeks to many years. Complete remissions may continue for years and be considered cures. If the disease returns, another remission often can occur with further treatment. A cancer that has recurred may respond to a different type of therapy, including a different drug combination.
What Is Staging?
Staging is the process of finding out how far the cancer has spread. Staging the cancer is a vital step in determining your treatment choices, and it will also give your health care team a clearer idea of the outlook for recovery.
Staging can take time, and people are usually anxious to begin treatment soon. Do not worry that the staging process is taking up treatment time. Keep in mind that by staging the cancer, you and your health care team will know which treatments are likely to be the most effective before beginning the treatment. For additional information, please see Staging.
There is more than one system for staging. The TNM system is the one used most often. It gives three key pieces of information:
T describes the size of the tumor, and whether the cancer has spread to nearby tissues and organs.
N describes how far the cancer has spread to nearby lymph nodes.
M shows whether the cancer has spread (metastasized) to other organs of the body.
Letters or numbers after the T, N, and M give more details about each of these factors. For example, a tumor classified as T1, N0, M0 is a tumor that is very small, has not spread to the lymph nodes, and has not spread to distant organs of the body. Once the TNM descriptions have been established, they can be grouped together into a simpler set of stages, stages 0 through stage IV (0-4).
In general, the lower the number, the less the cancer has spread. A higher number, such as stage IV (4), means a more serious, widespread cancer.
After looking at your test results, your doctor will tell you the stage of your cancer. Be sure to ask your doctor any questions you might have about what the stage of your cancer means and how it will impact your treatment options.
How Is Cancer Treated?
The number of treatment choices you have will depend on the type of cancer, the stage of the cancer, and other individual factors such as your age, health status, and personal preferences. You are a vital part of your cancer care team - you should discuss with them which treatmment choices are best for you. Don't be afraid to ask as many questions as you have. Make sure you understand your options. A cancer diagnosis usually gives people a sense of urgency in making choices about treatment and services. However, take the time to consider all the options available to you so you will be as well informed as possible.
How is Cancer Treated?
The four major types of treatment for cancer are surgery, radiation, chemotherapy, and biologic therapies. You might also have heard about hormone therapies such as tamoxifen and transplant options such as those done with bone marrow.
What Treatment Will Be Best for Me?
Your cancer treatment will be entirely based on your unique situation. Certain types of cancer respond very differently to different types of treatment, so determining the type of cancer is a vital step toward knowing which treatments will be most effective. The cancer's stage (how widespread it is) will also determine the best course of treatment, since early-stage cancers respond to different therapies than later-stage ones. Your overall health, your lifestyle, and your personal preferences will also play a part in deciding which treatment options will be best for you. Not all types of treatment will be effective in your situation, so be sure that you understand your options. Don't be afraid to ask questions; it is your right to know what treatments are most likely to help you and what their side effects may be.
Palliative versus Curative Goals: Before starting treatment, ask about the goal of treatment. Is the purpose of the treatment to cure the cancer, control it, or treat symptoms? Sometimes the goal of treatment can change.
Biologic Therapies
There is a lot of evidence that suggests that the immune system, the body's natural defense mechanism, plays a major role in the body's response to cancer. At least some forms of cancer occur when the immune system fails to destroy cancer cells or to prevent their growth. Biologic therapy is an effective treatment for certain cancers. It is sometimes called immunotherapy, biotherapy, or biological response modifier therapy. Biologic therapies use the body's immune system to fight cancer or to lessen the side effects of some cancer treatments.
Biologic therapies can act in several ways in cancer treatment. These include interfering with cancer cell growth, acting indirectly to help healthy immune cells control cancer, and helping to repair normal cells damaged by other forms of cancer treatment.
There are several kinds of biologic therapy now in use. More than one kind of biologic therapy may be used, or biologic therapy may be combined with chemotherapy or radiation therapy to treat cancer.
Complementary and Alternative Therapy
People have many different opinions about alternative and complementary therapies. You may hear words such as questionable, unorthodox, unconventional, new age, holistic, natural, or herbal used to describe these therapies. Some people look on them with disdain, while others strongly subscribe to their use. Standard or conventional treatment refers to mainstream medical treatments that have been tested following a strict set of scientific guidelines and found to be safe and effective. Alternative therapy refers to treatments that have not proven to be effective in treating a particular disease and are used instead of conventional treatment. Examples of these include hydrogen peroxide therapy, hydrazine sulfate, and essiac tea.
Complementary therapy refers to non-medical treatments used along with conventional medical treatments to help control symptoms and improve well-being. Examples include relaxation massage, and biofeedback. The goal of complementary therapy treatments is not to cure disease, but to help relieve symptoms or side effects. The term integrative medicine is used to describe the combination of mainstream and complementary methods.
Integrative medicine is safest and most effective when it is supervised by your doctor. Some herbal extracts (like echinachea, ginkgo, or valerian root) can actually be very potent or even dangerous, especially in combination with other medications. Before using any complementary therapy, be sure to discuss it with your doctor. There are many complementary methods you can safely use along with standard treatment to relieve symptoms or side effects, to ease pain, and to help you enjoy life more. Complementary methods that some people have found helpful when used along with medical treatment include aromatherapy, art therapy, biofeedback, massage, meditation, music therapy, prayer, t'ai chi, and yoga. If you are interested in complementary methods of treatment but are still unsure, gather all of the information you can so you can make an informed decision. However, be wary of any method that claims it can cure cancer.
Chemotherapy
While surgery and radiation therapy are used to treat localized cancers, chemotherapy is used to treat cancer cells that have metastasized (spread) to other parts of the body. Depending on the type of cancer and its stage of development, chemotherapy can be used to cure cancer, to keep the cancer from spreading, to slow the cancer's growth, to kill cancer cells that may have spread to other parts of the body, or to relieve symptoms caused by cancer.
Chemotherapy is treatment with powerful medicines that are most often given by mouth or by injection. Unlike radiation therapy or surgery, chemotherapy drugs can treat cancers that have spread throughout the body, because they travel throughout the body in the bloodstream. Often, a combination of chemotherapy is used instead of a single drug.
Chemotherapy is given in cycles, each followed by a recovery period. The total course of chemotherapy is often about six months, usually ranging from three to nine months. After a cancer is removed by surgery, chemotherapy can significantly reduce the risk of cancer returning. The chances of cancer returning and the potential benefit of chemotherapy depend on the type of cancer and other individual factors. For more information, please see our section on Making Treatment Decisions: Chemotherapy Principles.
Side effects of chemotherapy
Side effects of chemotherapy depend on the type of drugs, the amounts taken, and the length of treatment. The most common are nausea and vomiting, temporary hair loss, increased chance of infections, and fatigue. Many of these side effects can be uncomfortable or emotionally upsetting. However, most side effects can be controlled with medicines, supportive care measures, or by changing the treatment schedule. If you experience side effects, ask your doctor about ways to help ease or eliminate them. Also, keep your doctor informed of all side effects that you experience, as some may require immediate medical attention.
Fatigue is one of the most common side effects of radiation and chemotherapy. Like most other side effects, it will disappear once the treatment is complete. You can help yourself by getting enough rest, eating a well-balanced diet, drinking plenty of liquids, and by planning your activities to include frequent rest periods.
Though it is not medically harmful, hair loss can be an upsetting side effect. Most people feel that their hairstyle is a part of their identity, so it is only normal that hair loss is distressing. Some people experience hair loss during chemotherapy treatments (and sometimes with radiation treatment to the head) while others do not, even with the same drugs. Not all drugs cause hair loss. When it does occur, the hair almost always grows back after the treatments are completed. If hair loss does occur, it usually begins within two weeks of the start of therapy and gets worse 1-2 months after the start of therapy. Hair regrowth often begins even before therapy is completed. Most people are able to find suitable ways of managing the hair loss until it grows back, with specially designed hats, scarves, and wigs.
People having chemotherapy sometimes become discouraged about the length of time their treatment is taking or the side effects they are having. If that happens to you, talk to your doctor. There are ways to reduce the side effects or make them easier to manage. Keep in mind that the expected benefits of the treatment should outweigh any problems you might have because of it.
Cancer Pain
Pain is one of the reasons people fear cancer so much. If someone you know has cancer, it is normal to be afraid of witnessing pain. In fact, there are some cancers, which cause no physical pain at all. When it does occur, cancer pain can happen for a variety of reasons. Some people have pain as a result of the growth of a tumor or as a result of advanced cancer, while others may experience pain as a result of treatment side effects.
You should also know that doctors can treat and manage cancer pain with modern techniques and medicines. A great deal of progress has been made in pain control, so pain can be reduced or alleviated in almost all cases. Even patients with advanced disease can be kept comfortable.
You may also be concerned that someone taking pain medication for cancer will become addicted to the medication. However, all evidence shows that people who take prescribed drugs for cancer pain do not become addicted. In addition, some methods of pain reduction, such as acupuncture and guided imagery, do not involve drugs.