Basic Cancer Facts

For many people, there is nothing more frightening than a diagnosis of cancer. Fortunately, however, tremendous strides have been made in recent years in our understanding of cancer and its treatment. If you, a family member or a friend has been diagnosed with cancer, it is a good idea to learn as much as possible about the disease and its treatment — information is a powerful weapon in the fight against cancer.

The following includes basic information from the American Cancer Society. It is not intended as medical advice, nor is it intended to answer all of your questions. But it may help you understand the nature of the disease and how it can be treated. If you have any of the signs and symptoms of cancer described below, contact your physician immediately. If you have questions about your personal health, you should discuss them with your personal physician or other appropriate health care professionals.

For information about care at Rush University Medical Center in Chicago, visit our Cancer Programs Home Page.

What is cancer?

Cancer occurs when abnormal cells begin to grow out of control.

What is metastasis?

Metastasis is when cancer cells travel from the original tumor to other areas of the body, begin to multiply and replace normal tissue. This happens when cancer cells get into the bloodstream or lymphatic system.

If cancer starts in the breast and then travels to the liver, is it called liver cancer or breast cancer?

Cancer types are defined by where they originate. If cancer begins in the breast and moves to the liver, it is still considered breast cancer.

What causes cancer?

Damage to DNA — the complex genetic material that directs cells to perform specific activities — causes cancer cells to develop. Usually the body is able to repair damaged DNA, but in instances of cancer this does not happen. DNA damage can be inherited or it can be caused by exposure to elements in the environment, such as smoke.

What is remission?

Remission is when cancer is in control or responding to treatment. Complete remission is when all the signs and symptoms of cancer are gone. Partial remission is when the cancer shrinks but does not disappear. Remissions can last from weeks to years. Complete remissions may continue for years and be considered cures. If the cancer returns, repeated remissions can happen with additional treatments.

What is a stage?

The stage of cancer defines how far cancer has spread. Cancer stages help physicians determine treatment options and help physicians assess a patient’s prognosis. The process of staging can take time, but it is an important part of the treatment process.

What do stages mean?

Cancer is classified in stages that indicate how advanced the disease is. Although there is more than one system for staging, the TNM system 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.

How is cancer treated?

Treatment choices depend on the type of cancer, the stage of the cancer and other individual factors such as age, health status and personal preferences.
The following are types of cancer treatment:

• Surgery
• Radiation
• Chemotherapy
• Biologic or immune therapies
• Bone marrow transplantation  (including autologous and allogeneic transplantation)

What are the risk factors for cancer?

A risk factor is something that increases the likelihood of getting a disease. Some risk factors can be changed, whereas 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 his or her life. 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. According to the American Cancer Society, 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. 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, including tobacco use, diet and infectious diseases, as well as chemicals and radiation cause an estimated 75 percent of all cancer cases in the United States. Among these factors, tobacco use, unhealthy diet and lack of 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.

What are the signs and symptoms of cancer?

The following are some general signs and symptoms of cancer.

Unexplained weight loss: Most people with cancer will experience weight loss at some time with their disease. An unexplained 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. Almost all patients with cancer will experience fever at some time, particularly if the cancer or its treatment affects the immune system and reduces resistance to infection.

Fatigue: Fatigue may be a significant symptom as cancer progresses. It may occur early, especially if the cancer is causing a chronic loss of blood as in some colon cancer or stomach cancers.

Pain: Pain may be an early sign with some cancers, such as bone cancers or testicular cancer. Most often, pain is a symptom of advanced disease.

Skin clues: In addition to cancers of the skin, some internal cancers can produce visible skin signs such as darkening of the skin, reddening, itching and excessive hair growth.

In addition to these general symptoms, the American Cancer Society has established the following seven common symptoms that could lead to a diagnosis of cancer.

1. A 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 change in bladder function could be related to bladder or prostate cancer. Any changes in bladder or bowel function should be reported to your doctor.
   
2. 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 for patients who smoke, chew tobacco or frequently drink alcohol. Sores on the penis or vagina should not be overlooked.
   
3. Unusual bleeding or discharge. Unusual bleeding can occur in early or advanced cancer. Blood in the sputum is a sign of lung cancer. Blood in the stool could be a sign of colon or rectal cancer. Cancer of the lining of the uterus (endometrial cancer) or cervix 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.
   
4. 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. You may be feeling a lump that is an early cancer that could be treated successfully.
   
5. Indigestion or difficulty swallowing. These symptoms may indicate cancer of the esophagus, stomach or throat.
   
6. Recent change in a wart or mole. A change in color, 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.
   
7. A nagging cough or hoarseness. A persistent cough that does not go away is a sign of lung cancer. Hoarseness can be a sign of cancer of the larynx (voice box) or thyroid. These are often late signs of cancer.