About Cancer

What is cancer?

Cancer is not a single disease, but more than 100 different diseases. It is caused by the abnormal growth of cells in the body.

The body is made up of billions of cells. These cells reproduce by dividing. Through this process the body grows and repairs itself. Sometimes, a cell begins dividing abnormally and tumors form. Tumors may be benign or malignant. Malignant tumors (cancers) can spread to other tissues or organs nearby or to other parts of the body. This is called metastasis. Cancers grow at different speeds. Some grow very quickly; others may grow slowly over many years.

Some cancers are easily cured; others are more difficult to treat. This depends largely on the place in the body where the cancer cells grow, how large the tumor is when it is first found, and if it has spread. Doctors usually consider tumors that start in different parts of the body (not those that spread, but new tumors) to be different diseases. Generally, each type of cancer has its own symptoms, outlook for cure, and methods for treatment.
What causes cancer?

No one knows for sure why a normal cell becomes a cancer cell. Many causes of cancer have been identified. Sometimes there is a family history of cancer. Scientists agree that people can get cancer through repeated long-term contact with carcinogens. These include tobacco, sunlight, x-rays, and certain chemicals that may be found in the air, water, food, drugs and workplace. Our personal habits and lifestyle may contribute to most cancers. It is believed that about 30% of cancer deaths are due to tobacco. As many as 30% of cancer deaths may also be due to inadequate physical activity, obesity and an unhealthy diet.
How soon after exposure to a carcinogen does cancer appear?

Most cancers develop slowly in people. They usually appear five to 40 years after exposure to a carcinogen. For example, cancer of the lung may not occur until 30 years after a person starts smoking. This long latency period is one of the reasons it is difficult to determine what causes cancer in humans.
Who gets cancer?

Cancer is a very common disease. One of every two men, and one of every three women, will be diagnosed with cancer at some time in their life. In New York, nearly one in four deaths is due to cancer.

Cancer occurs at all ages, but most often in middle-aged and older people. The number of people diagnosed with cancer has increased over the past 40 years. Most of this is due to an increase in the population and because people are living longer.

The most common cancers diagnosed among men, besides skin, are prostate, lung and colon. Among women, they are cancers of the breast, lung and colon.


Source :health.state.ny.us