How Cancer Develops and Spreads
Cancer is a disease that happens when some of your body’s cells start growing and multiplying without control. This can build up to form a mass of cells, called a tumour. Cancer can occur in any type of cell in your body. As these abnormal cells grow and spread, they can damage your healthy cells and organs. Cancer can also make your immune system weaker and cause other health problems.
In the past, scientists could not explain how cancer developed or why it was so dangerous. Scientists now know that cancer occurs when normal controls in your body’s cells break down. This process is called carcinogenesis (4). Changes (mutations) in genes can cause these controls to break down. Mutations can also happen when cells are damaged, for example by radiation or chemicals.
A mutation may give a cancer cell some kind of advantage that allows it to grow and divide more quickly than other cells. This gives the cancer cell more chance to pass on its genetic changes (through inheritance) to future generations of cells. Over time, a cancer cell can accumulate many more mutations than the average normal cell. As these mutations accumulate, the cancer cell becomes more aggressive and can start to invade nearby tissue. This is called clonal selection.
As a result of accumulating mutations and heritable changes, some cancer cells are better adapted than others to survive, proliferate, and thrive. These cells are able to take advantage of the environment around them and compete for resources such as nutrients and space with other cancer cells, and even with normal cells in the area. Because of this, these mutations can cause cancer cells to develop resistance to certain treatments and evade the body’s natural defences.
The way that cancer grows and spreads can vary between different types of cancer. However, all cancers share some characteristics. For example, they often develop in parts of the body that are exposed to the sun or where the blood circulates. They can also grow very fast and invade surrounding tissues to spread. They also tend to make enzymes that break down normal cells and tissues as they grow. As they grow, these cancer cells push on normal tissues and can break blood vessels – this is called invasive or malignant cancer.
Most cancers have no single known cause. Instead, they often develop due to a complex mix of factors like getting older, smoking tobacco or not protecting your skin from the sun. This means that, for the most part, there are things that you can do to lower your risk of developing cancer, such as having screening tests and keeping a healthy weight. However, some cancers can develop in people who don’t have any known risk factors.
Cancer is a disease that happens when some of your body’s cells start growing and multiplying without control. This can build up to form a mass of cells, called a tumour. Cancer can occur in any type of cell in your body. As these abnormal cells grow and spread, they can damage your healthy cells and organs. Cancer can also make your immune system weaker and cause other health problems. In the past, scientists could not explain how cancer developed or why it was so dangerous. Scientists now know that cancer occurs when normal controls in your body’s cells break down. This process is called carcinogenesis (4). Changes (mutations) in genes can cause these controls to break down. Mutations can also happen when cells are damaged, for example by radiation or chemicals. A mutation may give a cancer cell some kind of advantage that allows it to grow and divide more quickly than other cells. This gives the cancer cell more chance to pass on its genetic changes (through inheritance) to future generations of cells. Over time, a cancer cell can accumulate many more mutations than the average normal cell. As these mutations accumulate, the cancer cell becomes more aggressive and can start to invade nearby tissue. This is called clonal selection. As a result of accumulating mutations and heritable changes, some cancer cells are better adapted than others to survive, proliferate, and thrive. These cells are able to take advantage of the environment around them and compete for resources such as nutrients and space with other cancer cells, and even with normal cells in the area. Because of this, these mutations can cause cancer cells to develop resistance to certain treatments and evade the body’s natural defences. The way that cancer grows and spreads can vary between different types of cancer. However, all cancers share some characteristics. For example, they often develop in parts of the body that are exposed to the sun or where the blood circulates. They can also grow very fast and invade surrounding tissues to spread. They also tend to make enzymes that break down normal cells and tissues as they grow. As they grow, these cancer cells push on normal tissues and can break blood vessels – this is called invasive or malignant cancer. Most cancers have no single known cause. Instead, they often develop due to a complex mix of factors like getting older, smoking tobacco or not protecting your skin from the sun. This means that, for the most part, there are things that you can do to lower your risk of developing cancer, such as having screening tests and keeping a healthy weight. However, some cancers can develop in people who don’t have any known risk factors.