Cancer of the bladder is the most frequently occurring malignant tumor in the urinary tract, affecting men more often than women. Although it can strike at any age, it usually occurs between the ages of 50 and 70.

Most bone tumors are considered secondary tumors because they have developed from cancer cells that spread from a primary malignant tumor to the bone.

Most bone cancers are called secondary tumors because they arise from other cancers that have spread from other parts of the body. Cancers that actually arise in the bones are relatively uncommon.

Cancer of the brain is less common than cancer in other locations of the body. Only about two percent of brain tumors originate in the brain. These are called primary brain tumors.

Cancer of the eye is relatively rare. It can affect several areas of the eye: the eye socket and its protective tissues, the eye ball, the eye membranes, and the eyelid.

According to the American Cancer Society, cancer of the gallbladder is the fourth most common cancer arising from the gastrointestinal tract, representing approximately two to three percent of all cancers in the United States.

Although cancer primarily affects adults, childhood forms of the disease do occur. Fortunately, cancer in children is very rare and most children diagnosed with cancer are successfully treated and cured.

The large intestine consists of the colon and rectum, which make up the final portion of the digestive tract. Cancer of the colon is the third most common cancer in men and the second most common cancer in women.

Cervical cancer usually grows very slowly and goes through several precancerous stages before there are any signs of malignancy. The earliest of these precancerous stages is called dysplasia (diss-PLAY-zhuh).

Esophageal (e-sof-a-JEE-uhl) cancer occurs most often in people age 50 to 70. The esophagus (e-SOF-a-gus) is a muscular tube that carries food from the throat to the stomach.

The gastrointestinal tract, or digestive system, processes the food we eat, extracting nutrients and removing waste in the form of stool from the body.

Hodgkin's disease is a cancer of the lymph (limf) nodes. Although it can strike at any age, it is most common among children and young adults. Hodgkin's disease often begins as a swelling of a lymph node in the neck or just under the collar bone.

Hurthle (HER-thel) cell carcinoma is a form of thyroid cancer. There are four types of thyroid cancer, one of which is follicular (fa-LICK-you-lur). Hurthle cell carcinoma is a variant of follicular thyroid cancer, representing about four percent of all thyroid cancer cases.

The kidneys are a pair of organs found just above the waist on either side of the spine. As part of the urinary tract, they filter waste out of the blood and make urine.

Leukemia is a cancer of the blood-forming tissues, which include bone marrow, lymph nodes, and spleen. Though it is the chief cause of death from disease in children ages three to 14, leukemia is more common in adults.

Cancer originating in the liver is relatively rare in this country. It occurs most often after age 45. It is more common in men than women. Causes of liver cancer are unknown, but it occurs most often in population groups with a high incidence of viral hepatitis (hep-ah-tie-tis), and certain other chronic liver diseases, including cirrhosis (sa-row-sis).

Lung cancer is the leading cause of cancer death among men and women. The most common risk factor for lung cancer is smoking, due to the harmful carcinogens (car-sin-ah-jens) found in tobacco smoke.

Lymphomas are cancers of the lymph system. The lymph system includes the lymph nodes, or lymph glands, which are located throughout the body, the tonsils, adenoids, thymus and spleen.

Cancers of the mouth and pharynx (FARE-inks) are usually easy to see and diagnose. These include the formation of whitish patches or reddened, velvety patches on the lining of the mouth and throat.

The pancreas (PAN-cre-us) is a gland situated behind the stomach. It secretes (suh-CRETES) pancreatic (PAN-cre-attic) fluid containing enzymes (EN-zimes) to aid in food digestion, and it also contains groups of cells that secrete insulin that helps regulate blood sugar levels.

According to the American Cancer Society, the United States has one of the world's highest rates of rectal cancer. Rectal cancer is rare in young people, with incidence rising sharply after age 50.

Renal (ree-nal) means pertaining to the kidneys; carcinoma (car-sa-noma) is a type of cancer that originates in the epithelial (epa-thee-lee-ul) cells located in glands, skin, and mucous membranes.

Sarcoma (sar-com-a) is a malignant tumor found in muscle, bone, cartilage, and fibrous tissue. Sarcoma is named according to the type of tissue in which it begins to grow.

Stomach cancer is common worldwide, but in the United States its incidence has declined significantly in the last 45 years. Studies have implied that diet and other environmental factors are the reason for this change.

The most common throat cancer is cancer of the larynx (lar-nix) or voice box. Risk factors include heavy smoking and drinking, voice strain, exposure to wood and metal dusts, and repeated inhaling of certain chemical substances.

Your thyroid is located in your neck just behind the Adam's apple. It consists of two lobes attached by a small isthmus (ist-mus). The thyroid is responsible for producing a hormone that's important in many of the body's functions, including metabolism.

The ureter (you-REE-ter) is the tube connecting the kidneys to the bladder through which urine passes. Ureteral (you-REE-teral) cancer occurs most frequently between the ages of 60 and 70.