Cancer – A Disease That Starts in One Cell and Grows Out of Control
Cancer is a disease that starts in one or more types of cells and grows out of control. It is a large group of diseases with many different kinds of tumors, each with its own characteristics and behavior. Depending on the type of cancer, it can affect different parts of the body and cause many health problems. Cancer can be treated by surgery, radiation therapy, chemotherapy, or other medicines. Researchers are studying ways to prevent cancer and ways to cure it.
When cancer starts, cells divide more often than normal cells and don’t die when they should. As a result, the number of cancer cells quickly grows and they can outnumber healthy cells. Cancerous cells can also grow and spread to other areas of the body. Some types of cancer can be more serious than others.
Scientists believe that cancer is caused by changes (mutations) in the genes. Some mutations are inherited from parents, while others happen when cells divide. Mutations can also be caused by things in the environment, such as tobacco smoke and sunlight. Mutations can change how cells respond to signals that control cell growth and death. They can also change how cells make energy from nutrients.
There are two main types of cancer: solid tumors, which start in cells that line tissues like the skin and lungs, and blood cancers, which start in blood-forming cells, such as those in the bone marrow. Each cancer is named after the tissue where it starts, or the cell type from which it originates.
The first step in cancer development is a series of mutations in genes, called oncogenic mutations. These mutations can lead to a series of events that give the cancer its distinctive features.
These mutations can make cells grow and divide too much, or they can ignore signals that stop cell growth or tell cells to die (programmed cell death). They can also evade the body’s controls on blood vessels that supply tumors with oxygen and nutrients or remove waste from them. Cancers can also trick the immune system into helping them stay alive and grow.
Scientists now know that all cancers start in one or more cells and grow out of control. They also know that the earliest stages of cancer, when it is still very small and limited to a single area of the body, are similar for all cancers.
In a few years, improvements in screening and treatments will likely help reduce the number of new cases of cancer and the number of deaths from cancer. However, some people will always develop cancer. Researchers are trying to find ways to stop new cancers from starting, especially in young people. They are examining things that can increase the chance of cancer, such as smoking and exposure to UV rays, and things that protect against cancer, such as good diet, exercise, and avoiding infections.
Cancer is a disease that starts in one or more types of cells and grows out of control. It is a large group of diseases with many different kinds of tumors, each with its own characteristics and behavior. Depending on the type of cancer, it can affect different parts of the body and cause many health problems. Cancer can be treated by surgery, radiation therapy, chemotherapy, or other medicines. Researchers are studying ways to prevent cancer and ways to cure it. When cancer starts, cells divide more often than normal cells and don’t die when they should. As a result, the number of cancer cells quickly grows and they can outnumber healthy cells. Cancerous cells can also grow and spread to other areas of the body. Some types of cancer can be more serious than others. Scientists believe that cancer is caused by changes (mutations) in the genes. Some mutations are inherited from parents, while others happen when cells divide. Mutations can also be caused by things in the environment, such as tobacco smoke and sunlight. Mutations can change how cells respond to signals that control cell growth and death. They can also change how cells make energy from nutrients. There are two main types of cancer: solid tumors, which start in cells that line tissues like the skin and lungs, and blood cancers, which start in blood-forming cells, such as those in the bone marrow. Each cancer is named after the tissue where it starts, or the cell type from which it originates. The first step in cancer development is a series of mutations in genes, called oncogenic mutations. These mutations can lead to a series of events that give the cancer its distinctive features. These mutations can make cells grow and divide too much, or they can ignore signals that stop cell growth or tell cells to die (programmed cell death). They can also evade the body’s controls on blood vessels that supply tumors with oxygen and nutrients or remove waste from them. Cancers can also trick the immune system into helping them stay alive and grow. Scientists now know that all cancers start in one or more cells and grow out of control. They also know that the earliest stages of cancer, when it is still very small and limited to a single area of the body, are similar for all cancers. In a few years, improvements in screening and treatments will likely help reduce the number of new cases of cancer and the number of deaths from cancer. However, some people will always develop cancer. Researchers are trying to find ways to stop new cancers from starting, especially in young people. They are examining things that can increase the chance of cancer, such as smoking and exposure to UV rays, and things that protect against cancer, such as good diet, exercise, and avoiding infections.