Understanding Cancer

In this lesson, you will Learn About…

What cancer is.

Some causes of cancer.

How cancer is treated.

How can you reduce your risk of developing

cancer.

Understanding Cancer

The Vocabulary terms in this lesson are:

Cancer.

Tumor.

Benign.

Malignant.

Risk factor.

Carcinogens.

Radiation therapy.

Chemotherapy.

Cancer

Cancer is a disease that occurs when abnormal cells grow out of control.

The adult human body is made up of more than 50 trillion cells that are growing and reproducing themselves.

Although the majority of cells are normal, some cells are abnormal.

The body’s natural defenses usually destroy these abnormal cells, but sometimes an abnormal cell survives and starts to reproduce and form a tumor. A tumor can be benign or malignant. A malignant tumor is cancerous.

Forms of Cancer and Risk Factors

Here are some forms of cancer and their risk factors.

In females, it can affect the cervix, ovaries, and uterus. In males, it can affect the prostate gland and testicles.

Vary, but include age, family history of cancer, obesity, and smoking.

Reproductive

cancers

This is the second major cause of cancer death among women.

Family history. More common in women over age 50, but can also occur in younger women and in men.

Breast Cancer

Important FactsRisk FactorsForm of Cancer

Forms of Cancer and Risk Factors (cont’d.)

Form of Cancer

Risk Factors Important Facts

Colon and rectum cancers

A high-fat low-fiber diet; lack of physical activity; and smoking.

Cases have declined somewhat in recent years due to increased cancer screening and better treatments.

Leukemia Not generally known. May be linked to exposure to certain types of radiation and to certain chemicals.

This cancer causes a rise in abnormal white blood cells, hindering the body’s production of healthy blood cells.

Lung cancer

Smoking. This is the largest cause of cancer death. Nearly 80% of cases are related to smoking.

Forms of Cancer and Risk Factors (cont’d.)

Form of Cancer

Risk Factors Important Facts

Lymphoma Not generally known. Exposure to certain infections may play a part.

This cancer of the lymph tissue weakens the immune system, leaving the body more vulnerable to infection.

Skin cancers Sun exposure and light skin, hair, and eye coloring

This is the most common form of cancer in the United States. Some types are easier to treat than others.

Causes of Cancer

Like other noncommunicable diseases, some cancers can be linked to inherited traits, behavior choices, and environmental factors called carcinogens.

Usually a person has to be exposed to a carcinogen over a long period of time for cancer to develop.

Causes of Cancer (cont’d.)

Substances and conditions linked to the development of various types of cancer include:

Tobacco in any form. Ultraviolet rays from the sun. Certain types of radiation. Certain minerals and chemicals used in

construction and manufacturing, such as asbestos.

Air and water pollution. A diet high in fat and low in fiber.

Combating Cancer

The best defense against an existing cancer is early detection. To detect cancer early, doctors look for warning signs during exams.

Here are some useful tips for early detection:

Train yourself to become aware of any unusual changes in your body.

If you notice something abnormal, such as a mole or wart that changes size or color, tell your parents or guardians and see a doctor right away.

What Doctors Can Do

To treat cancer, doctors often use a combination of the following methods, depending on the type of cancer and how far it has progressed.

Surgery—Doctors remove tumors and other cancerous cells. Surgery is most effective when the cancer is confined to one area of the body.

Radiation therapy—This therapy works best when the cancer is limited to just one area, such as the skin.

Chemotherapy—This treatment is used to stop cancers that have spread throughout the body. It is also sometimes used to shrink tumors before surgery is performed.

What You Can Do

There are no guaranteed ways to prevent cancer. However, you can make the following choices to lower your risk for developing certain cancers:

Avoid tobacco use. Take action to detect cancer early by

performing self-examinations regularly. Limit sun exposure. Know the seven warning signs identified by

the American Cancer Society. An easy way to remember these signs is to think of the word CAUTION.

What You Can Do (cont’d.)

hange in bowel or bladder habits

sore that doesn’t heal

nusual bleeding or discharge

hickening or lump in breast or elsewhere

ndigestion or difficulty swallowing

bvious change in a wart or mole

agging cough or hoarseness

Reviewing Terms and Facts

1. Define the term cancer.

Cancer is a disease that occurs when abnormal cells grow out of control.

Reviewing Terms and Facts

2. What is the difference between a tumor that is benign and one that is malignant?

A benign tumor is not cancerous and does not spread. A malignant tumor is cancerous and may spread to other parts of the body.

Thinking Critically

3.How might knowing the seven warning signs of cancer help people protect themselves?

Knowing the seven warning signs of cancer will help detect cancer in its early stages when it is easiest to treat and recover from.

Vocabulary Review

Cancer is a disease that occurs when abnormal cells grow out of control.

Vocabulary Review

A tumor is a group of abnormal cells that forms a mass.

Vocabulary Review

A benign tumor is not cancerous and does not spread.

Vocabulary Review

A malignant tumor is cancerous and may spread to other parts of the body.

Vocabulary Review

A risk factor is a characteristic or behavior that increases the likelihood of developing a medical disorder or disease.

Vocabulary Review

Carcinogens are substances in the environment that cause cancer.

Vocabulary Review

Radiation therapy is a treatment that uses X rays or other forms of radioactivity to treat some types of cancer.

Vocabulary Review

Chemotherapy is the use of powerful drugs to destroy cancer cells.