Cancer – A Disease That Starts in Cells and Can Spread to Other Parts of the Body
Cancer is a disease that starts in cells and can spread to other parts of the body. Cancer is often treated with surgery, chemotherapy, or radiation therapy. Each type of treatment affects cancer differently. But cancer treatment is constantly improving. That’s one reason why diagnosis and death rates from cancer are dropping yearly.
Cells are the basic building blocks of all living things, from bacteria to multicellular organisms like plants and animals. When cells grow and divide too fast, they form growths called tumors. They can also break off and travel to distant places in the blood or lymph system, where they can grow into more tumors and cause serious health problems.
Doctors first recognized cancer as a disease when they observed that tumors tended to grow quickly, were able to spread from place to place in the body, and caused health problems. They also noticed that many people who received early treatment for cancer had a better outlook than those who did not receive treatment.
A person’s outlook depends on the type and stage of cancer, as well as how far it has spread from where it started. When cancer has not spread, it is called localized cancer and may be treated with surgery or other medicines or techniques.
When cancer has spread to other parts of the body, it is called metastatic or recurrent cancer and can be harder to treat. It is also more likely to return after treatment has been stopped.
The cancer cell’s ability to survive and grow is due to changes in the genes that control how the cell functions. This process is known as mutation and it usually results from natural selection, the force that drives a population to evolve in ways that favor certain traits (e.g., resistance to apoptosis or the ability to evade immune surveillance).
Mutations are part of life and can occur in any of our cells. The key is when a mutation in a cell triggers the cell to grow and divide out of control.
When a mutation in a cell triggers this uncontrolled growth, old or damaged cells do not die as they should and new cells are formed that can grow and divide without restraint. Normally, cells that divide too often or in an uncontrolled way are killed by the immune system. But when cancer cells develop, they are able to resist this natural process.
Cancer cells are also able to grow and survive because they have adaptations that help them thrive in the environment of a tumor. They can adapt by changing how they uptake nutrients, co-opt normal cells to perform their functions, evade immune attack, or produce “public goods” that benefit other tumor cells in the tumor microenvironment.
When cancer cells develop these adaptations, they gain a kind of evolutionary autonomy and become more like a species than the normal cells in the tissue where they originated. This process of evolution by mutation and natural selection is called speciation.
Cancer is a disease that starts in cells and can spread to other parts of the body. Cancer is often treated with surgery, chemotherapy, or radiation therapy. Each type of treatment affects cancer differently. But cancer treatment is constantly improving. That’s one reason why diagnosis and death rates from cancer are dropping yearly. Cells are the basic building blocks of all living things, from bacteria to multicellular organisms like plants and animals. When cells grow and divide too fast, they form growths called tumors. They can also break off and travel to distant places in the blood or lymph system, where they can grow into more tumors and cause serious health problems. Doctors first recognized cancer as a disease when they observed that tumors tended to grow quickly, were able to spread from place to place in the body, and caused health problems. They also noticed that many people who received early treatment for cancer had a better outlook than those who did not receive treatment. A person’s outlook depends on the type and stage of cancer, as well as how far it has spread from where it started. When cancer has not spread, it is called localized cancer and may be treated with surgery or other medicines or techniques. When cancer has spread to other parts of the body, it is called metastatic or recurrent cancer and can be harder to treat. It is also more likely to return after treatment has been stopped. The cancer cell’s ability to survive and grow is due to changes in the genes that control how the cell functions. This process is known as mutation and it usually results from natural selection, the force that drives a population to evolve in ways that favor certain traits (e.g., resistance to apoptosis or the ability to evade immune surveillance). Mutations are part of life and can occur in any of our cells. The key is when a mutation in a cell triggers the cell to grow and divide out of control. When a mutation in a cell triggers this uncontrolled growth, old or damaged cells do not die as they should and new cells are formed that can grow and divide without restraint. Normally, cells that divide too often or in an uncontrolled way are killed by the immune system. But when cancer cells develop, they are able to resist this natural process. Cancer cells are also able to grow and survive because they have adaptations that help them thrive in the environment of a tumor. They can adapt by changing how they uptake nutrients, co-opt normal cells to perform their functions, evade immune attack, or produce “public goods” that benefit other tumor cells in the tumor microenvironment. When cancer cells develop these adaptations, they gain a kind of evolutionary autonomy and become more like a species than the normal cells in the tissue where they originated. This process of evolution by mutation and natural selection is called speciation.