What Is Cancer?
Cancer is a term used to describe a collection of abnormal cells that can grow and spread into other parts of the body. It is a very broad category of diseases, and each type has its own set of symptoms, causes and treatment options.1
Normally, your cells are programmed to grow and multiply only in certain ways. But sometimes, a cell gets a mutation that changes its normal behavior. The mutation may allow the cell to grow and multiply rapidly without control. It may also stop working properly and prevent other cells from growing, or it may spread from one part of the body to another part through the bloodstream. Cancer can cause pain, swelling and other symptoms in the area where it begins. But it can also spread to other parts of the body, which may have no symptoms and is referred to as metastatic disease.
Scientists don’t know what causes most cancers. But they do know that certain things (called risk factors) increase your chances of getting them. For example, smoking and drinking too much alcohol increase your risk of developing some types of cancer. Some cancers can be caused by viruses or bacteria, and others develop because of inherited gene defects.
Cancer can be diagnosed either by signs and symptoms or through screening tests in healthy people. Most of the time, doctors suspect cancer when a person complains of unusual symptoms or undergoes a medical test because of another health problem. But some people who have cancer don’t experience any symptoms and are only diagnosed through screening tests like a colonoscopy or mammogram.
There are more than 100 different kinds of cancer. They differ in their appearance under a microscope and in how quickly they grow, whether they spread to other parts of the body and how they respond to treatment. Some cancers are treated best by surgery, while others are best treated with drugs or radiation.
Many of the drugs that treat cancer work by killing cancer cells or stopping them from growing. Often, these drugs are given together in a combination therapy called chemotherapy. They are sometimes given before surgery to help shrink a tumor and make it easier for the surgeon to remove the tumor, a procedure called neoadjuvant chemotherapy. They are also sometimes given after surgery to reduce the chance that the cancer will recur, a procedure called adjuvant chemotherapy.
Other forms of cancer are treated with radiation, surgery or other procedures to cut off blood supply to the tumor and kill the cancer cells. In some cases, cancer cells can be cured with targeted therapy that works on specific proteins that are important for cancer growth. New treatments are being tested all the time. These include photodynamic therapy, which uses light to activate cancer-fighting drugs and other ways to target the specific cells in the tumor. Scientists are also testing drugs that block the blood supply that cancer cells need, correct genetic defects in the cancerous cells and assist your own immune system to fight the cancer.
Cancer is a term used to describe a collection of abnormal cells that can grow and spread into other parts of the body. It is a very broad category of diseases, and each type has its own set of symptoms, causes and treatment options.1 Normally, your cells are programmed to grow and multiply only in certain ways. But sometimes, a cell gets a mutation that changes its normal behavior. The mutation may allow the cell to grow and multiply rapidly without control. It may also stop working properly and prevent other cells from growing, or it may spread from one part of the body to another part through the bloodstream. Cancer can cause pain, swelling and other symptoms in the area where it begins. But it can also spread to other parts of the body, which may have no symptoms and is referred to as metastatic disease. Scientists don’t know what causes most cancers. But they do know that certain things (called risk factors) increase your chances of getting them. For example, smoking and drinking too much alcohol increase your risk of developing some types of cancer. Some cancers can be caused by viruses or bacteria, and others develop because of inherited gene defects. Cancer can be diagnosed either by signs and symptoms or through screening tests in healthy people. Most of the time, doctors suspect cancer when a person complains of unusual symptoms or undergoes a medical test because of another health problem. But some people who have cancer don’t experience any symptoms and are only diagnosed through screening tests like a colonoscopy or mammogram. There are more than 100 different kinds of cancer. They differ in their appearance under a microscope and in how quickly they grow, whether they spread to other parts of the body and how they respond to treatment. Some cancers are treated best by surgery, while others are best treated with drugs or radiation. Many of the drugs that treat cancer work by killing cancer cells or stopping them from growing. Often, these drugs are given together in a combination therapy called chemotherapy. They are sometimes given before surgery to help shrink a tumor and make it easier for the surgeon to remove the tumor, a procedure called neoadjuvant chemotherapy. They are also sometimes given after surgery to reduce the chance that the cancer will recur, a procedure called adjuvant chemotherapy. Other forms of cancer are treated with radiation, surgery or other procedures to cut off blood supply to the tumor and kill the cancer cells. In some cases, cancer cells can be cured with targeted therapy that works on specific proteins that are important for cancer growth. New treatments are being tested all the time. These include photodynamic therapy, which uses light to activate cancer-fighting drugs and other ways to target the specific cells in the tumor. Scientists are also testing drugs that block the blood supply that cancer cells need, correct genetic defects in the cancerous cells and assist your own immune system to fight the cancer.