Cancer is a collection of many diseases that all involve growth of abnormal cells. The body is made up of many types of cells. Normally, cells grow, divide, and then die. Sometimes, cells mutate (change). They begin to grow and divide more quickly than normal cells. Rather than dying, these abnormal cells clump together to form tumors.
Sometimes these tumors are benign (not cancer). But if the cells in these tumors are cancerous (malignant), they can invade and kill your body’s healthy tissues. From these tumors, cancer cells can metastasize (spread) and form new tumors in other parts of the body. Cells in benign tumors do not spread to other parts of the body.
Symptoms of cancer
There are many different symptoms of cancer. Often, your symptoms will depend on what kind of cancer you have. For example, a symptom of breast cancer is a lump in the breast. A symptom of skin cancer is an abnormal-looking mole. General symptoms that tend to go with multiple types of cancer include:
What causes cancer?
Cancer is caused by mutations in the DNA in your cells. The DNA is inside your genes, which give instructions to the cells on what they are supposed to do. When the DNA mutates, it causes errors in the instructions. This makes the cell stop functioning normally. It can lead the cell to become cancerous.
Many things can cause your genes to mutate. Sometimes you are born with a mutation. This means you inherited it from your parents. More commonly, the mutations happen after you’re born. Factors that can cause this include:
Who is at risk for cancer?
Everyone has some risk for cancer. In the United States, cancer is likely to affect 1 in 2 men and 1 in 3 women at least once in their lifetime. The amount of risk you have depends on a number of factors. These factors include:
How is cancer diagnosed?
There are a variety of tests your doctor will need to do if he or she suspects cancer.
Physical exam: Your doctor will give you a thorough physical exam. He or she will check your body for lumps or tumors. They will check your skin for changes or enlargement of any areas.
Lab tests: They will likely order urine and blood tests that can find abnormalities that can be caused by cancer.
Imaging: These tests are not invasive. They take pictures of your bones and the inside of your body. They may include CT scans, bone scans, MRIs, ultrasounds, X-rays, and positron emission tomography (PET) scans.
Biopsy: If you have a tumor, your doctor will want to look at the cells inside. He or she will collect a sample of the cells. There are a variety of ways to do this. These often depend on what kind of cancer is suspected and where it is. A biopsy is the most definitive way to diagnose cancer.
What can I do to lower my risk of cancer?
Unfortunately, some risk factors for cancer (such as family history) are out of your control. But there are things you can do each day to improve your health and lower your risk of cancer. The best ways to lower your cancer risk are to:
The three most common types of cancer treatment are surgery, radiotherapy, and chemotherapy. Treatment is aimed at removing the cancer cells or destroying them with medicines or by other means.
Surgery is a way to physically remove the cancer. Surgery can be very successful in treating some kinds of cancer. But it isn’t an option in all cases. It may be possible to safely remove a tumor and any affected surrounding tissue if:
Radiotherapy uses radiation to damage cancer cells so that they can’t multiply. The radiation is in the form of special X-rays, gamma rays, or electrons. There is usually no pain during this kind of therapy. Depending on the area that is treated, side effects from radiation damage to normal tissues may occur. Your doctor can tell you what to expect.
Chemotherapy uses strong medicines to attack the cancer cells. The word “chemotherapy” sometimes causes a lot of fear because the side effects can be severe. However, not all people experience severe side effects. The side effects of chemotherapy can often be treated with other medicines.
Questions to ask your doctor