What Causes Cancer?
Cancer is a disease in which abnormal cells grow and spread to other parts of the body. Cancer is a very serious illness. It causes pain, discomfort, and sometimes death. It may also affect a person’s emotional well-being and disrupt relationships. Cancer can be caused by genetic changes and many different things in the environment. These include things people do and do not do, such as smoking cigarettes or taking medicine.
Normal cells are regulated by growth controls that limit their numbers and size, so they do not grow out of control. Cancer cells, however, do not have the same controls. They multiply much more quickly than normal cells. They also do not die when they are supposed to. In addition, they do not respond to cues that normally cause them to slow their rate of growth or to stop dividing.
Because of these factors, cancer cells can crowd out normal cells and damage tissues. They can also break off and travel through the blood or lymph system to distant parts of the body. This is called metastasis. Cancer cells can also grow inside the body and eat or destroy organs.
Cancer can be caused by gene changes, which may be inherited or happen during a person’s lifetime. It can also be caused by some things in the environment, such as viruses, toxins, or radiation.
Most cancers develop because of several gene changes. These can be passed down from parents, or they can happen because of lifestyle habits, such as smoking or eating unhealthy foods. Cancer can also be caused by a person’s job, such as working with chemicals or radiation.
Usually, cancer starts in cells that line tissues or make up skin. But it can also start in stem cells that make blood cells or other types of cells. Most types of cancer that grow in tissue (malignant) grow and form tumors, which are collections of abnormal cells. Some types of cancer, such as leukemias, are in the blood and do not form solid tumors.
A person who has cancer has a more chance of developing another cancer in the future. The risk increases with age and with certain lifestyle habits, such as tobacco use and a high-fat diet. It also is increased by certain infections, such as Helicobacter pylori infection, human papillomavirus infection, and infection with certain herpes viruses (human herpes simplex virus 1 and 2, Epstein-Barr virus, and Kaposi’s sarcoma-associated herpesvirus).
There are ways to reduce the chances of getting cancer. These include not smoking or using less tobacco, not over-exposing to sunlight, maintaining a healthy weight, and getting regular screening for cancers that can be found early, when they are easier to treat. The most common cancers are skin, lung, colorectal, breast, and pancreatic cancer. These cancers can be treated with surgery, radiation, or chemotherapy. Some cancers, such as leukemias and some lymphomas, can be prevented with vaccines. Other cancers can be treated with drugs that target specific proteins, such as rapamycin or methotrexate.
Cancer is a disease in which abnormal cells grow and spread to other parts of the body. Cancer is a very serious illness. It causes pain, discomfort, and sometimes death. It may also affect a person’s emotional well-being and disrupt relationships. Cancer can be caused by genetic changes and many different things in the environment. These include things people do and do not do, such as smoking cigarettes or taking medicine. Normal cells are regulated by growth controls that limit their numbers and size, so they do not grow out of control. Cancer cells, however, do not have the same controls. They multiply much more quickly than normal cells. They also do not die when they are supposed to. In addition, they do not respond to cues that normally cause them to slow their rate of growth or to stop dividing. Because of these factors, cancer cells can crowd out normal cells and damage tissues. They can also break off and travel through the blood or lymph system to distant parts of the body. This is called metastasis. Cancer cells can also grow inside the body and eat or destroy organs. Cancer can be caused by gene changes, which may be inherited or happen during a person’s lifetime. It can also be caused by some things in the environment, such as viruses, toxins, or radiation. Most cancers develop because of several gene changes. These can be passed down from parents, or they can happen because of lifestyle habits, such as smoking or eating unhealthy foods. Cancer can also be caused by a person’s job, such as working with chemicals or radiation. Usually, cancer starts in cells that line tissues or make up skin. But it can also start in stem cells that make blood cells or other types of cells. Most types of cancer that grow in tissue (malignant) grow and form tumors, which are collections of abnormal cells. Some types of cancer, such as leukemias, are in the blood and do not form solid tumors. A person who has cancer has a more chance of developing another cancer in the future. The risk increases with age and with certain lifestyle habits, such as tobacco use and a high-fat diet. It also is increased by certain infections, such as Helicobacter pylori infection, human papillomavirus infection, and infection with certain herpes viruses (human herpes simplex virus 1 and 2, Epstein-Barr virus, and Kaposi’s sarcoma-associated herpesvirus). There are ways to reduce the chances of getting cancer. These include not smoking or using less tobacco, not over-exposing to sunlight, maintaining a healthy weight, and getting regular screening for cancers that can be found early, when they are easier to treat. The most common cancers are skin, lung, colorectal, breast, and pancreatic cancer. These cancers can be treated with surgery, radiation, or chemotherapy. Some cancers, such as leukemias and some lymphomas, can be prevented with vaccines. Other cancers can be treated with drugs that target specific proteins, such as rapamycin or methotrexate.