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Anal cancer

Cancer that begins in the anus, the opening at the end of the large intestine where the waste from the body’s digestive system passes out of the body.


Hard, nonflammable fibers used for insulating buildings.


Made of a single cell, bacteria are the simplest organisms found in nature. Bacterial infections can often be treated with antibiotics.

Benign tumor

Not cancerous; tumor does not invade nearby tissue or spread to other parts of the body.


Diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread through the bloodstream and lymphatic system to other parts of the body.


A substance that causes cancer.


A cancerous growth made up of epithelial cells: cells from tissues that form the covering around organs, such as lung, liver, or breast, or the lining of blood vessels.


The basic unit of all living things. Organs are made up of millions of cells. Each cell contains several smaller components enclosed in a membrane.


Solid black material similar to charcoal that is left after burning coal. Coke is used as fuel and in making steel.

Colorectal cancer

Cancers that begin in either the colon or the rectum are called colorectal cancer. Together, the colon and rectum make up the large intestine, a long, muscular tube where the waste from the body’s digestive system is stored until it passes out of the body through the anus. The colon makes up the first four to five feet of the large intestine and the rectum is the last four to five inches.


Deoxyribonucleic acid is the molecule inside the cell that carries genetic information and is passed on from one generation to the next.


Tissue lining the wall of a woman’s uterus, the organ where a baby grows.


The study of the patterns of diseases in human populations and the factors that influence the patterns.

Familial cancers

Cancers that occur frequently in certain cancer-prone families in which a mutated gene that is associated with a high risk of developing cancer is passed on from one generation to the next.

Focus group

A qualitative research technique in which an experienced moderator leads about 8–10 participants through a semi-structured discussion on a selected topic, allowing them to talk freely and spontaneously.


An agent that destroys fungi.


Pieces of DNA, or heredity units found inside cells passed from parent to offspring. Genes contain the information for making proteins


An agent that destroys weeds.


The number of people who develop a disease divided by the number of people at risk of developing the disease in a specific time period.


An agent that destroys insects.


A type of cancer that forms from cells in the blood and bone marrow, including leukocytes or white blood cells that help the body fight infections and other diseases.

Linear dose response

A type of response in which the cancer risk changes at the same rate as the exposure—if the exposure increases, the cancer risk increases at the same rate. A cancer risk is present at all levels of exposure, even very low ones.

Lymphatic system

The tissues and organs that produce, store, and carry white blood cells, which fight infection and other diseases. This system includes the bone marrow, spleen, thymus, and lymph nodes, and a network of thin tubes that carry lymph and white blood cells to all the tissues of the body.


Cancer that arises in cells of the lymphatic system.

Malignant tumor

A cancerous growth with a tendency to invade and destroy nearby tissue and spread to other parts of the body.


A malignant form of skin cancer that arises in melanocytes, the cells that produce pigment. Melanoma usually begins in a mole.


The number of people who die from a disease divided by the number of people at risk of dying from the disease in a specific time period.


An altered gene that normally directs cell growth. An oncogene promotes uncontrolled growth of cancer. Alterations can be inherited, occur randomly, or be caused by an environmental exposure to carcinogens.


An agent used to destroy pests of any sort; the term includes fungicides, herbicides, and insecticides.


Molecules in the cell that perform a wide variety of functions, such as protection (skin), support/movement (muscles), transportation (e.g., hemoglobin transports oxygen), and activation of the chemical reactions that sustain life (e.g., enzymes for digesting food).


A cancer of the bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.


Plants where valuable metals are extracted from rocks or minerals.


A term used to describe someone who is more likely to develop a disease.

Threshold dose response

A type of response in which, at very low exposures, there appears to be no detectable increased risk of disease; there is a threshold below which no risk is detected.


A group or layer of cells, such as the skin, that together performs specific functions.


An abnormal mass of tissue that results from too much cell division. Tumors perform no useful body function. They may be either benign (not cancerous) or malignant (cancerous).

Tumor suppressor gene

A gene whose normal function is to prevent abnormal cells from dividing. Certain mutations in tumor suppressor genes lead to cancer.


Viruses are smaller than a single cell or bacteria and cannot reproduce outside a living organism.

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