Cancer – Causes and Treatments
Cancer is a disease that occurs when genes that manage cell activity become mutated. Cancer cells multiply and grow without control, spreading to nearby tissues or traveling through the blood and lymph systems to other parts of the body where they can form new tumors. Eventually, cancers interfere with the normal functions of tissues, organs and the entire body. The result is a complex mix of signs and symptoms that can be difficult to distinguish from other diseases. Cancers may be benign (not causing symptoms) or malignant (causing symptoms).
It is now understood that cancer develops when normal cells become mutated and lose the ability to stop growing or die. These mutations can be caused by many things, including cigarette smoking, radiation exposure and certain infections (such as Epstein-Barr virus infection, herpes viruses or human papillomavirus). It is also possible that cancers develop for no apparent reason. Until recently, scientists believed that the mutations that cause cancer occur randomly in normal cells. This led to the view that cancers were essentially genetic disorders.
However, more recent research has shown that the mutations that cause cancer are more likely to occur as a result of a series of events. These are called oncogenic events and include overexpression of cell growth factors, chromosome instability, abnormal DNA replication and activation of an enzyme that keeps chromosomes from being damaged during cell division. In addition, oncogenic events can cause normal cells to acquire traits that are characteristic of cancer cells.
These oncogenic events can be caused by environmental factors such as excessive sun exposure and overexposure to carcinogenic chemicals. Infections with certain bacteria, viruses and parasites may also increase the risk of developing cancer. In addition, genetic and hormonal factors can contribute to cancer development.
All cancers start in cells that were once part of healthy tissues, such as breast or colon cells. Cancers often appear as lumps or masses of cells. Some types of cancer grow very fast, while others grow more slowly. Some cancers spread from one part of the body to another, while others stay local.
When cancer is found, it can be treated with surgery, chemotherapy and/or radiation therapy. Treatments can reduce a person’s symptoms, improve their quality of life and help them live longer. When cancer is caught early, it tends to be smaller and more easily treatable. In general, a cancer must be more than a million cells in size or spread to other parts of the body before it is usually detectable by doctors. Cancers that begin in blood or bone marrow, such as leukemias and lymphomas, are sometimes detectable by laboratory tests before they are noticeable to people.
Most cancers can be prevented by practicing safe habits, such as not smoking, getting regular screenings with mammograms or colonoscopies and avoiding overexposure to sunlight. It is also important to get immunized against common infectious agents that can cause cancer. A person’s chances of surviving cancer depend on how soon it is diagnosed, whether they receive treatment and how well their treatment works.
Cancer is a disease that occurs when genes that manage cell activity become mutated. Cancer cells multiply and grow without control, spreading to nearby tissues or traveling through the blood and lymph systems to other parts of the body where they can form new tumors. Eventually, cancers interfere with the normal functions of tissues, organs and the entire body. The result is a complex mix of signs and symptoms that can be difficult to distinguish from other diseases. Cancers may be benign (not causing symptoms) or malignant (causing symptoms). It is now understood that cancer develops when normal cells become mutated and lose the ability to stop growing or die. These mutations can be caused by many things, including cigarette smoking, radiation exposure and certain infections (such as Epstein-Barr virus infection, herpes viruses or human papillomavirus). It is also possible that cancers develop for no apparent reason. Until recently, scientists believed that the mutations that cause cancer occur randomly in normal cells. This led to the view that cancers were essentially genetic disorders. However, more recent research has shown that the mutations that cause cancer are more likely to occur as a result of a series of events. These are called oncogenic events and include overexpression of cell growth factors, chromosome instability, abnormal DNA replication and activation of an enzyme that keeps chromosomes from being damaged during cell division. In addition, oncogenic events can cause normal cells to acquire traits that are characteristic of cancer cells. These oncogenic events can be caused by environmental factors such as excessive sun exposure and overexposure to carcinogenic chemicals. Infections with certain bacteria, viruses and parasites may also increase the risk of developing cancer. In addition, genetic and hormonal factors can contribute to cancer development. All cancers start in cells that were once part of healthy tissues, such as breast or colon cells. Cancers often appear as lumps or masses of cells. Some types of cancer grow very fast, while others grow more slowly. Some cancers spread from one part of the body to another, while others stay local. When cancer is found, it can be treated with surgery, chemotherapy and/or radiation therapy. Treatments can reduce a person’s symptoms, improve their quality of life and help them live longer. When cancer is caught early, it tends to be smaller and more easily treatable. In general, a cancer must be more than a million cells in size or spread to other parts of the body before it is usually detectable by doctors. Cancers that begin in blood or bone marrow, such as leukemias and lymphomas, are sometimes detectable by laboratory tests before they are noticeable to people. Most cancers can be prevented by practicing safe habits, such as not smoking, getting regular screenings with mammograms or colonoscopies and avoiding overexposure to sunlight. It is also important to get immunized against common infectious agents that can cause cancer. A person’s chances of surviving cancer depend on how soon it is diagnosed, whether they receive treatment and how well their treatment works.