Cancer Overview


What is cancer?

Cancer is one of the scariest words in the English language. When you hear the word as part of a diagnosis, it's natural to feel many emotions, especially fear.

A cancer diagnosis can cause you and your family a great deal of stress, but you have many resources to help you. You owe it to yourself to learn as much as possible about your diagnosis and how it can be treated. Knowledge is power, and it can help you deal with this disease.

Cancer is a disease that occurs when cells in the body begin to divide at a faster rate than the body requires. These rapidly dividing cells grow into a lump that is known as a tumor. The tumor can be benign (non-cancerous) or malignant (cancerous).

What is cancer staging?

One of the biggest concerns about a cancer diagnosis is whether the cancer has spread (metastasized) beyond its original location. To determine this, the doctor assigns a number (I through IV) to your diagnosis. The higher the number, the more the cancer has spread throughout your body. This is called "staging." The doctor needs this information in order to plan your treatment.

Symptoms and Causes

What are the causes of cancer?

Many factors can cause the development of cancer in the body. Some of these factors, such as heredity (family members who have the disease) cannot be avoided. Others, such as lifestyle, can be controlled.

For instance, the use of tobacco is one of the main causes of cancer, especially lung cancer. Tobacco use, whether in the form of smoking, chewing, or exposure to second-hand smoke (smoking by others), can also cause cancer of the mouth and larynx, esophagus, throat, and many other parts of the body.

Other primary causes of cancer include:

  • Diet/nutrition: The proper diet is always important, but a poor diet might also increase your risk of cancer. For instance, eating large amounts of high-fat foods can contribute to cancer of the colon and prostate. Exercise is also key. Excess weight might be a contributing factor for various types of cancer, including breast, uterus, ovary, prostate and colon.
  • Environment: Cancer can develop if the person is exposed over a period of time to various chemicals in the environment, including pesticides, asbestos and radon.
  • Exposure to radiation: Too much exposure to the sun (ultraviolet radiation) can cause skin cancer. In addition, over-exposure to X-rays or to radiation therapy (as part of cancer treatment) might be a risk factor for cancer.
  • Hormone therapy: Women who are going through menopause might receive a prescription for hormone replacement therapy, either estrogen alone or in combination with progesterone. The use of both of these hormones together has been shown to increase the risk of breast cancer. A woman who still has her uterus and is taking estrogen alone (without progesterone) has a greater risk of endometrial cancer.

What are the symptoms of cancer?

The most prominent symptoms of cancer include the following:

  • A sore that doesn't heal.
  • A wart or mole that changes.
  • An unusual lump anywhere in the body.
  • A persistent cough/hoarseness.
  • Indigestion or problems swallowing.
  • Changes in bowel movement or urination habits.
  • Unusual weight loss.
  • Unusual bleeding or discharge from various parts of the body.

Please note that these symptoms do not mean that you definitely have cancer. However, if any of these symptoms appear, you should see your doctor right away.

Diagnosis and Tests

How is cancer diagnosed?

If your doctor thinks you might have cancer, he or she will examine you and might order certain tests, including:

  • Blood and urine tests.
  • Imaging tests that allow the doctor to see the inside your body to see if cancer is present (Imaging tests include X-rays, computed tomography (CT) scans, magnetic resonance imaging (MRI), radionuclide scanning and ultrasonography.)
  • Biopsy, a procedure in which the doctor takes a small sample of the tumor and analyzes it under a microscope.

Management and Treatment

What are the treatments for cancer?

In order to treat your cancer, your doctor needs to know the location of the tumor, the stage (whether it has spread) and whether you are strong enough to handle the treatment.

Cancer treatment can take the following forms:

  • Chemotherapy: This treatment uses powerful drugs that destroy the cancer cells. Chemotherapy is delivered orally (pills) or through an intravenous (IV) line.
  • Radiation : This is a treatment that kills cancerous cells with radiation (high-energy rays). Radiation therapy can either be internal (placed within the body) or external (delivered by a machine outside the body). Note: In some cases, radiation therapy and chemotherapy are given to a patient at the same time.
  • Surgery: A surgeon removes the tumor, along with the surrounding area (in some cases).
  • Hormone therapy: Hormones (substances produced by the glands to regulate organ functions) might be given to the patient to block other hormones that might cause cancer. For example, men with prostate cancer might be given hormones to keep testosterone (which contributes to prostate cancer) at bay.
  • Biological response modifier therapy: Biological response modifier therapy uses natural or artificial (created in a laboratory) materials to rebuild the body's natural defenses against disease. Biological therapy includes immunotherapy, gene therapy, vaccines, monoclonal antibody therapy and some targeted therapies. (Monoclonal antibodies are created in a laboratory to work like natural antibodies, which are produced by the body's immune system to fight disease.)
  • Immunotherapy: A type of biological therapy that uses substances that work on the immune system to help the body fight cancer, infection, and other diseases. Some types of immunotherapy only target certain cells of the immune system. Others affect the immune system in a general way. Types of immunotherapy include cytokines, vaccines, bacillus Calmette-Guerin (BCG) and some monoclonal antibodies.
  • Stem cell transplantation: Stem cells (immature cells from which all blood cells develop) are removed from the patient's circulating blood or bone marrow and then returned after chemotherapy treatment.

What are the side effects of cancer treatments?

  • Chemotherapy: Side effects include hair loss, fatigue, nausea, vomiting.
  • Radiation: Side effects include fatigue, hair loss, and skin problems (darkening, dryness, itchiness).
  • Surgery: Pain and weakness are possible side effects of surgery.
  • Hormone therapy: This therapy can result in fatigue, water retention (bloating), hot flashes, impotence and blood clots.
  • Biological response modifier therapy/immunotherapy: These therapies can cause symptoms that resemble the flu (fever, chills, muscle ache, etc.), skin rash, swelling and increased tendency to bruise or bleed.
  • Stem cell transplantation: Side effects include nausea, vomiting, flu-like symptoms and greater risk of infection.

What happens after my cancer treatment ends?

After cancer treatment ends, all cancer survivors should have follow-up care. Follow-up care for cancer means seeing a healthcare provider for regular medical checkups once you're finished with treatment. These checkups may include bloodwork, as well as other tests and procedures that look for any changes in your health, or any problems that may occur due to your cancer treatment.

These visits are also a time to check for physical and emotional problems that may develop months or years after treatment ends. Your follow-up care plan, along with a summary of your cancer treatment, is part of what is called a survivorship care plan. This plan will have all the information for you and your doctor to discuss to ensure that you get regular and thorough care after your treatment ends. Please note that it’s important that you continue to receive your routine care from your primary care provider in addition to follow-up cancer care.

Once your treatment ends, you should receive a follow-up cancer care plan from your oncologist or someone on your treatment team. A follow-up care plan is a set of recommendations for your cancer care after treatment ends. Many cancer organizations recommend the use of such a document.

For follow-up cancer care, you may see the same doctor who treated you for cancer, or you may see another healthcare provider, such as one who specializes in follow-up care for cancer survivors. Or you may decide to go to your primary care doctor. You can discuss which doctor(s) to see with your healthcare team.

Follow-up care for childhood cancer survivors is very similar to the steps for adults.

Common questions after treatment ends

When you receive your follow-up care plan from your doctor or other healthcare provider, answers to the questions below should be provided. Make sure to ask any other questions you may have:

  • How long will it take for me to get better and feel more like myself?
  • Which doctor(s) should I see for my follow-up care? How often?
  • What symptoms should I watch out for?
  • What tests do I need after treatment is over? How often will I have them?
  • What are long-term health issues I might expect as a result of my cancer treatment?
  • What is the chance that my cancer will return?
  • What records do I need to keep about my treatment?
  • What can I do to take care of myself and be as healthy as possible?
  • Can you suggest a support group that might help me?

You might find it helpful to write these questions down. When you meet with the doctor or follow-up care specialist, you can take notes or record your talks to refer to later. Talk about any concerns you have related to your follow-up care plan

Your follow-up care schedule

Each patient has a different follow-up care schedule. How often you return for follow-up visits is based on:

  • The type of cancer you had.
  • The treatment you received.
  • Your overall health, including possible treatment-related problems.

In general, people return to the doctor for follow-up appointments every three to four months during the first two to three years after treatment, and once or twice a year after that.

At these visits, you may have a physical exam along with blood tests and other necessary tests and procedures. Which tests you receive and how often you receive them will be based on what your doctor thinks is best for you when creating your follow-up care plan.

What to tell your doctor during follow-up visits

When you meet with your doctor for follow-up visits, it’s important to talk openly about any physical or emotional problems you’re having. Always mention any symptoms, pain or concerns that are new or that won’t go away. But keep in mind that just because you have new symptoms, it doesn’t necessarily mean the cancer has come back. It’s normal to have fears about every ache and pain that arises, but they may just be problems that your doctor can easily address.

Other things you should tell your doctor:

  • Any physical problems that interfere with your daily life, such as fatigue; problems with bladder, bowel, or sexual function; having a hard time concentrating; memory changes; trouble sleeping; or weight gain or loss.
  • Any new medicines, vitamins, herbs, or supplements you’re taking.
  • Changes in your family medical history.
  • Any emotional problems you’re having, such as anxiety or depression.

It’s important to be aware of any changes in your health between scheduled visits. Report any problems to your doctor immediately. They can decide whether the problems are related to the cancer, the treatment you received or an unrelated health issue.

Your treatment summary

Your oncologist or a member of your treatment team should give you a written summary of the treatment you received. Keep this with you to share with your primary care doctor and any other doctors you see. Many people keep their treatment summary in a binder or folder, along with their medical records. This way, key facts about your treatment will always be in the same place.

Types of health information in the treatment summary include:

  • The date you were diagnosed.
  • The type of cancer you had.
  • Pathology report(s) that describe the type and stage of cancer in detail.
  • Places and dates of each treatment, such as the details of all surgeries; the sites and total amounts of radiation therapy; and the names and doses of chemotherapy and all other drugs.
  • Key lab reports, X-ray reports, CT scans and MRI reports.
  • List of signs and symptoms to watch for and possible long-term effects of treatment.
  • Contact information for all health professionals involved in your treatment.
  • Any problems that occurred during or after treatment.
  • Any supportive care you received during treatment (such as medicines for depression or anxiety, emotional support and nutritional supplements).

Many cancer survivors say that getting involved with their follow-up care was a good way for them to regain some of the control they felt they lost during cancer treatment. Being an active partner with your doctor and asking for help from other members of the healthcare team is the first step. Knowing what to expect after cancer treatment can help you and your family make plans, lifestyle changes and important decisions about the future.

Guidelines for a healthy lifestyle after cancer treatment

After cancer treatment, many survivors want to find ways to reduce the chances of their cancer coming back. Some worry that the way they eat, the stress in their lives or their exposure to chemicals may put them at risk for recurrence. Cancer survivors find that this is a time when they take a good look at how they take care of themselves and how they might live a healthier life.

Ask your doctor about developing a survivorship care plan that includes ways you can take care of your physical, emotional, social and spiritual needs. If you find that it's hard to talk about these issues, it may be helpful to know that the more you do it, the easier it becomes. Your doctor may also suggest another member of the health care team for you to talk with about wellness, such as a social worker, nutritionist, clergy member or nurse.

Some general tips for all cancer survivors include:

Quit smoking. Smoking after cancer treatment can increase the chances of getting cancer at the same or a different site.
Cut down on how much alcohol you drink. Drinking alcohol increases the risk of certain cancers.
Maintain a healthy weight. Eating well and staying active can help you reach a healthy weight and stay there. Eat well. A healthy and balanced diet is important for overall wellness. This includes eating fruits, vegetables, whole grains and protein. Talk with your doctor or a dietitian to find out about any special dietary needs that you may have. You could also ask if you should talk to a nutritionist for guidance on eating a healthy diet.
Exercise and stay active. Research suggests that staying active after cancer may help lower the risk of recurrence and lead to longer survival. In addition, moderate exercise (walking, biking, swimming) for about 30 minutes every—or almost every—day can:

  • Reduce anxiety and depression.
  • Improve mood and boost self-esteem.
  • Reduce fatigue, nausea, pain and diarrhea.

It’s important to start an exercise program slowly and increase activity over time. Some people may need to take special care in exercising. Talk with your doctor before you begin any exercise program, and work with your doctor or a specialist (such as a physical therapist) if needed. If you need to stay in bed during your recovery, even doing small activities can help. Stretching or moving your arms or legs can help you stay flexible and relieve muscle tension.


What other resources are available to deal with cancer?

If you are diagnosed with cancer, it's important to realize that you are not alone. You have your family and friends, and there are support groups for nearly every type of cancer. Ask your doctor for information about these groups. You can also contact your local chapter of the American Cancer Society for more information.

In addition, your doctor can refer you to a social worker or a mental health professional, both of whom can help you deal with the emotional aspects of your diagnosis. The social worker can also help you with the practical and financial issues related to the disease.

Last reviewed by a Cleveland Clinic medical professional on 07/27/2016.


  • American Cancer Society.Accessed 5/22/2020. Cancer A-Z. (
  • National Cancer Institute. Accessed 5/22/2020.About Cancer (
  • Centers for Disease Control and Prevention. 5/22/2020. Kinds of Cancer. (

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