What is Cancer?
Cancer is an abnormal cell growth that can spread to other parts of the body. It is a very serious disease and can cause many different symptoms.
Cancer can also lead to other health problems such as heart problems, lung problems, nerve damage and infection. Some types of cancer are easier to treat than others. For example, some cancers can be cured with surgery, radiation or medicine. Other treatments such as chemotherapy or immunotherapy can help make the cancer cells less likely to grow or spread.
Researchers continue to learn more about how and why cancer grows and develops. They are discovering new treatments and figuring out how to prevent cancer from coming back.
Scientists have long known that cancer is a genetic disorder. It happens when genes that control how cells work mutate. Mutations can be caused by chemicals, radiation or viruses. They can also happen naturally over time. Scientists have also learned that sometimes cancer seems to run in families.
A person can get cancer at any age. But it is more common as people get older. It is also more common in people who have a family history of the disease, or of another type of cancer. It is important to tell a doctor about any new or unusual symptoms.
In the late 1800s, scientists had three basic theories about how cancer might be caused. Virchow believed that cancer was the result of chronic irritation; Lobstein and Recamier thought it was the result of displaced embryonal tissue; and Cohnheim suggested that it was caused by germs. Many experiments were made to try to induce cancer in experimental animals based on these theories. But the cancerous growths that resulted were not consistent with any of these theories.
Cancer cells are different from normal cells in that they are not subject to homeostatic (physiological) controls that limit their growth and development. This lack of regulation allows cancer cells to proliferate and grow rapidly. As cancer cells grow and divide, they accumulate genetic mutations. Over time, these mutations can lead to more aggressive and malignant features that drive the cancer cells to survive, thrive and reproduce.
Eventually, the mutations in cancer cells cause them to become more aggressive and to resist treatment. During this process, they can acquire traits that allow them to better adapt to the tumor microenvironment. This adaptation process is similar to the processes that lead to species evolution by natural selection.
For example, as cancer cells grow and multiply, they can learn to ignore signals that normally tell cells to stop growing or to die (a process called programmed cell death). They can also grow blood vessels that supply them with oxygen and nutrients. They can hide from the immune system, which normally eliminates damaged or abnormal cells. They can also trick the body’s other cells into helping them grow and survive.
Cancer is an abnormal cell growth that can spread to other parts of the body. It is a very serious disease and can cause many different symptoms. Cancer can also lead to other health problems such as heart problems, lung problems, nerve damage and infection. Some types of cancer are easier to treat than others. For example, some cancers can be cured with surgery, radiation or medicine. Other treatments such as chemotherapy or immunotherapy can help make the cancer cells less likely to grow or spread. Researchers continue to learn more about how and why cancer grows and develops. They are discovering new treatments and figuring out how to prevent cancer from coming back. Scientists have long known that cancer is a genetic disorder. It happens when genes that control how cells work mutate. Mutations can be caused by chemicals, radiation or viruses. They can also happen naturally over time. Scientists have also learned that sometimes cancer seems to run in families. A person can get cancer at any age. But it is more common as people get older. It is also more common in people who have a family history of the disease, or of another type of cancer. It is important to tell a doctor about any new or unusual symptoms. In the late 1800s, scientists had three basic theories about how cancer might be caused. Virchow believed that cancer was the result of chronic irritation; Lobstein and Recamier thought it was the result of displaced embryonal tissue; and Cohnheim suggested that it was caused by germs. Many experiments were made to try to induce cancer in experimental animals based on these theories. But the cancerous growths that resulted were not consistent with any of these theories. Cancer cells are different from normal cells in that they are not subject to homeostatic (physiological) controls that limit their growth and development. This lack of regulation allows cancer cells to proliferate and grow rapidly. As cancer cells grow and divide, they accumulate genetic mutations. Over time, these mutations can lead to more aggressive and malignant features that drive the cancer cells to survive, thrive and reproduce. Eventually, the mutations in cancer cells cause them to become more aggressive and to resist treatment. During this process, they can acquire traits that allow them to better adapt to the tumor microenvironment. This adaptation process is similar to the processes that lead to species evolution by natural selection. For example, as cancer cells grow and multiply, they can learn to ignore signals that normally tell cells to stop growing or to die (a process called programmed cell death). They can also grow blood vessels that supply them with oxygen and nutrients. They can hide from the immune system, which normally eliminates damaged or abnormal cells. They can also trick the body’s other cells into helping them grow and survive.