What Causes Cancer?
Cancer is a disease that happens when the cells that make up your tissues and organs start to grow and divide without control. Cancer can be deadly, because it can spread to other parts of the body and destroy healthy tissue. But scientists still don’t know exactly what causes most types of cancer. They do know that some people are more likely to get cancer than others. That’s partly because genes influence how your body works. But also because of things you do, such as smoking and being exposed to chemicals called carcinogens.
There are more than 100 different kinds of cancer. But all cancers start when your body’s cells begin to grow and multiply out of control. The abnormal cells can become a lump or tumor, which is a group of cells that has accumulated too much tissue and lost their ability to stop growing and dividing. The resulting tumour is often shaped like the part of your body that it is in. Sometimes, these cells can break away and move to other parts of your body. These new tumours are called secondary or metastatic cancers. They can be less serious than the cancer that started in the place where it first developed, which is called the primary tumour.
Cells in multicellular organisms, including mammals and humans, have a built-in limit on how many times they can divide. After a certain number of divisions, most cells die and are replaced by new cells that have the same genetic characteristics as the original cells. But, if one of your body’s cells develops a mutation that prevents it from dying or stopping its growth and proliferation, the abnormal cell can continue dividing. The result can be a tumour that forms in the place where it started, or it can spread to other places in your body.
Most cancers develop from changes (mutations) in your DNA. These mutations can happen by chance when your cells are dividing, or they can be caused by something you do, such as smoking or exposure to chemicals, or by things in the environment that can damage DNA, such as viruses or radiation. Sometimes, these mutations can also be inherited.
Then, if these mutations are not blocked by your immune system or other normal controls, they can accumulate and continue to reproduce. The resulting population of cancer cells evolves through natural selection, just as individual organisms do in their environment, to develop adaptations that allow them to survive and thrive in the tumor microenvironment. These adaptations may include increased uptake of nutrients, evasion of the immune system or recruitment of other cancer cells to help them grow.
There are ways to lower your risk of getting cancer, such as eating a balanced diet and staying physically active. Keeping weight in a healthy range, not smoking and using sunscreen can also help reduce your risk of cancer. In addition, it is important to have regular checkups to identify and treat problems before they become cancer.
Cancer is a disease that happens when the cells that make up your tissues and organs start to grow and divide without control. Cancer can be deadly, because it can spread to other parts of the body and destroy healthy tissue. But scientists still don’t know exactly what causes most types of cancer. They do know that some people are more likely to get cancer than others. That’s partly because genes influence how your body works. But also because of things you do, such as smoking and being exposed to chemicals called carcinogens. There are more than 100 different kinds of cancer. But all cancers start when your body’s cells begin to grow and multiply out of control. The abnormal cells can become a lump or tumor, which is a group of cells that has accumulated too much tissue and lost their ability to stop growing and dividing. The resulting tumour is often shaped like the part of your body that it is in. Sometimes, these cells can break away and move to other parts of your body. These new tumours are called secondary or metastatic cancers. They can be less serious than the cancer that started in the place where it first developed, which is called the primary tumour. Cells in multicellular organisms, including mammals and humans, have a built-in limit on how many times they can divide. After a certain number of divisions, most cells die and are replaced by new cells that have the same genetic characteristics as the original cells. But, if one of your body’s cells develops a mutation that prevents it from dying or stopping its growth and proliferation, the abnormal cell can continue dividing. The result can be a tumour that forms in the place where it started, or it can spread to other places in your body. Most cancers develop from changes (mutations) in your DNA. These mutations can happen by chance when your cells are dividing, or they can be caused by something you do, such as smoking or exposure to chemicals, or by things in the environment that can damage DNA, such as viruses or radiation. Sometimes, these mutations can also be inherited. Then, if these mutations are not blocked by your immune system or other normal controls, they can accumulate and continue to reproduce. The resulting population of cancer cells evolves through natural selection, just as individual organisms do in their environment, to develop adaptations that allow them to survive and thrive in the tumor microenvironment. These adaptations may include increased uptake of nutrients, evasion of the immune system or recruitment of other cancer cells to help them grow. There are ways to lower your risk of getting cancer, such as eating a balanced diet and staying physically active. Keeping weight in a healthy range, not smoking and using sunscreen can also help reduce your risk of cancer. In addition, it is important to have regular checkups to identify and treat problems before they become cancer.