Cancer Basics

You will learn and grow as you go through the cancer experience. Many people are surprised to find a new inner strength and courage. Healing can happen on physical, emotional and spiritual levels. This can even bring a renewed outlook on life.

Defining Cancer

All cancers begin in the body’s cells. Normal cells grow and divide to produce more cells as older cells die off. This keeps the body healthy. However, if the genetic material (DNA) of a cell is damaged or changed, the abnormal cells can invade other tissues. New cells form when the body does not need them or old cells don't die when they should. These cancer cells can spread through the blood and lymph systems to other parts of the body. The extra cells form a mass of tissue called a growth or tumor.

The National Cancer Institute (NCI) defines cancer as a group of more than 100 related but separate diseases. Cancer is categorized by where the disease begins in the body and not by where it has spread. Here are the main categories of cancer:

• Carcinoma begins in the skin or tissues that line or cover internal organs.
• Sarcoma begins in bone, cartilage, fat, muscle, blood vessels or other connective or supportive tissue.
• Leukemia starts in blood-forming tissue, such as the bone marrow, and causes abnormal blood cells to be produced.
• Lymphoma and myeloma begin in the cells of the immune system.
• Central nervous system cancers begin in the tissues of the brain and spinal cord.

Not all tumors are cancerous. They can be benign (noncancerous) or malignant (cancerous). Cells in malignant tumors are abnormal and divide without control or order. They metastasize or spread and destroy the tissue around them. Cancer cells spread through the blood and lymph systems.

Cancer Causes

Certain factors can change normal genes into those that allow the growth of cancer. These factors include tobacco use, dietary choices and too much exposure to ultraviolet light, chemicals or certain substances. The risk of developing certain types of cancer might also be inherited. If there is a history of specific types of cancer in your family, such as breast or colon cancers, talk with your health care provider. Discuss a referral to test for your genetic risk. However, even if a genetic risk exists, cancer may never actually develop.

It is not your fault if you get cancer. There are many cancer myths about what causes the disease. Wrong beliefs that are shared by others can be hurtful and confusing. For example, it is not true that someone who has the disease can spread cancer. An injury or bruise does not cause cancer. If you are unsure about what you hear or read, talk with your health care provider.

Signs and Symptoms

Some people experience early signs or symptoms that something is wrong. They may experience fatigue or weight changes that cannot be explained. Others might have a type of cancer that develops slowly and has no early symptoms.

Cancer may be discovered through:

• Routine physical exams.
• Follow-up exams because of a lump or growth.
• Lab testing of blood, urine or tissue.
• Screening tests, such as a Pap test, mammogram, fecal occult blood test or a colonoscopy.
• X-rays and digital imaging done for other reasons such as an injury. Digital imaging may include computed tomography (CT or CAT) scans, positron emission tomography (PET) scans or magnetic resonance imaging (MRI) testing.

Diagnostic Tests

If cancer is suspected, your health care provider will schedule tests to confirm a diagnosis. These are some of the most common tests:

• Biopsy involves either surgery or a hollow needle. A small amount of tissue, bone or bone marrow is collected. The sample is then sent to a pathology lab to check for cancer cells under a microscope.
• Blood or urine testing is done to learn more about the type of cancer and if it is affecting other parts of the body.
• Imaging studies (such as a CT, PET or MRI scan) are done to show the presence, location and size of an abnormal mass (tumor).

Before you go through testing, ask your health care provider if some types of tests are better for your situation than others. For example, if you want to have children in the future, your provider may decide to avoid certain types of procedures. Ask a friend or loved one to go with you to medical appointments.

Some medications used during testing have side effects, such as fatigue. Be sure to tell your health care provider about any physical and emotional concerns that you have as you go through the diagnosis process. Concerns could include depression, fatigue, pain, sexual issues, digestion and urinary or bowel problems. Information that you share can help your provider make the diagnosis and plan for the best treatment.

Cancer Stages

Your health care provider may prescribe further testing to identify the stage of cancer. The stage describes how cancer has affected the body. Cancer stages are based on:

• The size of a tumor.
• Whether cancer is in the lymph nodes.
• Whether cancer has spread to other parts of the body (metastatic) or is limited to a certain area (localized).

With certain types of cancer, health care providers use the term “grade” to describe the way thin slices of cancer tissue appear when they are viewed under a microscope. Grading generally ranges from very well differentiated or nearly normal (grade 1) to very poorly differentiated (grade 5). Lower numbers (Stages I and II) are used for the early stages of cancer. Higher numbers (Stages III and IV) indicate that the disease is more advanced.

Early diagnosis and treatment methods have greatly improved the chance of recovery for many types of cancer. Testing has become more accurate. It is a good idea to get other medical opinions before making decisions about treatment. Getting more than one medical opinion may help you make the best decision.