Cancer Types, Symptoms, In-Depth
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Cancer

Show Alternative Names
Carcinoma
Malignant tumor

Cancer is the uncontrolled growth of abnormal cells in the body. Cancerous cells are also called malignant cells.

Causes

Cancer is made of cells in the body. Normal cells multiply when the body needs them, and die when they are damaged or the body doesn't need them.

Cancer occurs when the genetic material of a cell becomes changed. This results in cells growing out of control. Cells divide too quickly and do not die in a normal way.

There are many kinds of cancer. Cancer can develop in almost any organ or tissue, such as the lung, colon, breast, skin, bones, or nerve tissue.

There are many risk factors for cancer, including:

  • Smoking tobacco or other substances
  • Chewing tobacco
  • Benzene and other chemical exposures
  • Drinking too much alcohol
  • Environmental toxins, such as certain poisonous mushrooms and a type of mold that can grow on peanut plants and produce a toxin called aflatoxin
  • Genetic problems
  • Obesity
  • Radiation exposure
  • Too much sunlight exposure
  • Viruses

The cause of many cancers remains unknown.

The most common cause of cancer-related death is lung cancer.

In the United States, skin cancer followed by breast cancer are the most commonly diagnosed cancers.

In US men, other than skin cancer, the three most common cancers are:

Video Transcript

Prostate cancer - Animation

As men get older, they have a lot of new worries to deal with, from hair loss, weight gain, perhaps even erectile dysfunction. In addition, cancer is one of the biggest concerns that older men face, especially prostate cancer, which is the leading cause of cancer death in men over 75. Younger men may not be very familiar with their prostate, the walnut-shaped gland that wraps around the urethra, the tube that carries urine out of the body. But as they get older, the prostate can start to cause problems. Men over the age of 60 are at increased risk for prostate cancer, especially if they're of African descent, they have a father or brother with the disease, or they eat a lot of burgers and processed meats in their daily diet. It can be hard to pinpoint prostate cancer symptoms, because they usually start late in the disease and they can mimic symptoms of a benign, enlarged prostate, which is also more common in older men. Symptoms like a slow urine stream, dribbling, blood in the urine, or straining while urinating can be signs of either condition. An enlarged prostate can also confuse the results of a PSA test, which is used to screen for prostate cancer. So, if your doctor thinks you might have prostate cancer, you may need a biopsy, which is a procedure that removes a small piece of prostate tissue and sends it to the lab to check for cancer. Then a scoring system called the Gleason grade is used to tell how fast your cancer might spread. Your Gleason grade will help decide what treatment you get. Early-stage prostate cancers that haven't spread are often removed with surgery, and then treated with radiation therapy to kill any remaining cancer cells. Prostate cancer surgery may affect your ability to have sex and control urine, so talk about these issues with your doctor before you have the procedure. Because prostate cancer tends to grow very slowly, your doctor may want to just monitor you with PSA tests and biopsies, and avoid treatment unless the cancer starts to spread. Prostate cancer that has spread is usually treated with surgery, chemotherapy, or hormone therapy. If your doctor discovers prostate cancer in its early stages, before it spreads, it's pretty easy to treat, and even cure. Treatments can also slow down prostate cancer that's spread, and extend your survival. Before you have to deal with a prostate cancer diagnosis, ask your doctor for ways to prevent and screen for the disease. Eating a healthy, low-fat diet that's high in healthy omega-3 fatty acids might help lower your risk. There are also drugs called finasteride and dutasteride that are used in some men to prevent prostate cancer. Talk with your doctor about the pros and cons of these drugs, as well as the possible benefits and risks of having your PSA levels tested.

In US women, other than skin cancer, the three most common cancers are:

  • Breast cancer
  • Lung cancer
  • Colorectal cancer

Video Transcript

Breast cancer - Animation

Of all the different types of cancers, breast cancer is one of the most talked about, and with good reason. One out of every eight women will develop breast cancer sometime in their life. That's why every woman should be thinking about how to protect herself from this disease. Breast cancer is cancer that forms in the breast. Usually, it begins in the tubes that transport milk from the breast to the nipple. If the cancer spreads to other parts of the breast or body, it's called invasive breast cancer. Some breast cancers are more aggressive, growing more quickly than others. Although women are 100 times more likely to develop breast cancer, men can also get the disease because they do have breast tissue. You're more likely to get breast cancer if you're over 50, you started your periods before age 12, or you have a close family member with the disease. Drinking more than a couple of glasses of alcohol a day and using hormone replacement therapy for several years also may increase your risk. The telltale sign of breast cancer is a lump in your breast or armpit. You may also notice a change in the shape, size, or texture of your breast, or have fluid coming from your nipple when you're not breastfeeding. If you notice any changes in your breasts, call your doctor. You'll probably need to have an imaging scan, such as a mammogram, MRI, or ultrasound. A piece of tissue may be removed from your breast, called a biopsy. With these tests, your doctor can tell whether you have breast cancer, and if so, determine whether or not it has spread. So, how do we treat breast cancer? That really depends on the type of cancer, and how quickly it's spreading. Your doctor may recommend that you have the cancer removed with surgery. Sometimes it's enough just to remove the lump. That's called a lumpectomy. In other cases, the doctor will need to remove the entire breast to get rid of all the cancer or prevent it from coming back. That's called a mastectomy. Other treatments for breast cancer include chemotherapy, medicines that kill cancer cells, and radiation therapy, which uses energy to destroy cancer. Women whose cancer is fueled by the hormone estrogen may receive hormone therapy to block the effects of estrogen on their cancer. Today's breast cancer treatments are better than ever. Many women who have breast cancer go on to live long, healthy lives. The outlook really depends on how fast the tumor is growing, and how far it has spread. That's why it's so important to report any changes in your breasts to your doctor as soon as you notice them. Women who are at an especially high risk for breast cancer because of their family history can talk to their doctor about taking medicine or even having surgery to reduce their risk.

Some cancers are more common in certain parts of the world. For example, in Japan, there are many cases of stomach cancer. But in the United States this type of cancer is much less common. Differences in diet or environmental factors may play a role.

Some other types of cancer include:

Symptoms

Symptoms of cancer depend on the type and location of the cancer. For example, lung cancer can cause coughing, shortness of breath, or chest pain. Colon cancer may cause diarrhea, constipation, or blood in the stool.

Some cancers may not have any symptoms. In certain cancers, such as pancreatic cancer, symptoms often do not start until the disease has reached an advanced stage.

The following symptoms may occur with cancer:

  • Chills
  • Fatigue
  • Fever
  • Loss of appetite
  • Malaise
  • Night sweats
  • Pain
  • Weight loss

Exams and Tests

Like symptoms, the signs of cancer vary based on the type and location of the tumor. Common tests include the following:

Most cancers are diagnosed by biopsy. Depending on the location of the tumor, the biopsy may be a simple procedure or a serious operation. Most people with cancer have CT scans to determine the exact location and size of the tumor or tumors.

A cancer diagnosis is often difficult to cope with. It is important that you discuss the type, size, and location of the cancer with your health care provider when you are diagnosed. You also will want to ask about treatment options, along with the prognosis (likely outcome), benefits, and risks.

It's a good idea to have someone with you at the provider's office to help you get through and understand the diagnosis. If you have trouble asking questions after hearing about your diagnosis, the person you bring with you can ask them for you.

Treatment

The treatment varies, based on the type of cancer and its stage. The stage of a cancer refers to how much it has grown and whether the cancer has spread from its original location.

  • If the cancer is in one location and has not spread, the most common treatment approach is surgery to cure it. This is often the case with skin cancers, as well as cancers of the lung, breast, and colon.
  • If the cancer has spread to local lymph nodes only, sometimes these can also be removed with the cancer.
  • If surgery cannot remove all of the cancer, the options for treatment may include radiation, chemotherapy, immunotherapy, targeted cancer therapies, or other types of treatment. Some cancers require a combination of treatments. Lymphoma, or cancer of the lymph glands, is rarely treated with surgery. Chemotherapy, immunotherapy, radiation therapy, and other nonsurgical therapies are often used.

Although treatment for cancer can be difficult, there are many ways to keep up your strength.

If you have radiation treatment:

  • Treatment is usually scheduled every weekday.
  • You should allow 30 minutes for each treatment session, although the treatment itself usually takes only a few minutes.
  • You should get plenty of rest and eat a well-balanced diet during the course of your radiation therapy.
  • Skin in the treated area may become sensitive and easily irritated.
  • Some side effects of radiation treatment are temporary. They vary, depending on the area of the body that is being treated.

If you have chemotherapy:

  • Eat well.
  • Get plenty of rest, and don't feel like you have to accomplish tasks all at once.
  • Avoid people with colds, the flu, COVID-19, or any other infectious illness. Chemotherapy can cause your immune system to weaken.

Talk with family, friends, or a support group about your feelings. Work with your providers throughout your treatment. Helping yourself can make you feel more in control.

Support Groups

The diagnosis and treatment of cancer often causes a lot of anxiety and can affect a person's entire life. There are many resources for people with cancer.

Outlook (Prognosis)

The outlook depends on the type of cancer and the stage of the cancer when diagnosed.

Some cancers can be cured. Other cancers that are not curable can still be treated effectively. Some people can live for many years with cancer. Other cancers are quickly life threatening.

Possible Complications

Complications depend on the type and stage of cancer. The cancer may spread.

When to Contact a Medical Professional

Contact your provider if you develop symptoms of cancer.

Prevention

You can reduce the risk of getting a cancerous (malignant) tumor by:

  • Eating healthy foods
  • Exercising regularly
  • Limiting alcohol use
  • Maintaining a healthy weight
  • Minimizing your exposure to radiation and toxic chemicals
  • Not smoking or chewing tobacco
  • Reducing sun exposure, especially if you burn easily

Cancer screenings, such as mammography for breast cancer and stool blood testing or colonoscopy for colon cancer, may help catch these cancers at their early stages when they are most treatable. This is particularly valuable in people with a family history of cancer. Some people at high risk for developing certain cancers can take medicines to reduce their risk.

Review Date: 1/1/2025

Reviewed By

Frank D. Brodkey, MD, FCCM, Associate Professor, Section of Pulmonary and Critical Care Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

References

Basen-Engguist K, Brown P, Coletta AM, Savage M, Maresso KC, Hawk E. Lifestyle and cancer prevention. In: Niederhuber JE, Armitage JO, Kastan MB, Doroshow JH, Tepper JE, eds. Abeloff's Clinical Oncology. 6th ed. Philadelphia, PA: Elsevier; 2020:chap 22.

Doroshow JH. Approach to the patient with cancer. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2025:chap 164.

National Cancer Institute website. Chemotherapy and you: support for people with cancer. www.cancer.gov/publications/patient-education/chemo-and-you. Updated January 2024. Accessed December 30, 2024.

National Cancer Institute website. Radiation therapy and you: support for people with cancer. www.cancer.gov/publications/patient-education/radiation-therapy-and-you. Updated April 2021. Accessed December 30, 2024.

Siegel RL, Giaquinto AN, Jemal A. Cancer statistics, 2024. CA Cancer J Clin. 2024;74(1):12-49. PMID: 38230766 pubmed.ncbi.nlm.nih.gov/38230766/.

Disclaimer

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

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Videos
Images
Lung cancer

Lung cancer

Animation

Breast cancer

Breast cancer

Animation

Cervical cancer

Cervical cancer

Animation

Colon cancer

Colon cancer

Animation

Prostate cancer

Prostate cancer

Animation

Open biopsy of the breast - Illustration Thumbnail

Open biopsy of the breast

An open biopsy can be performed under local or general anesthesia and will leave a small scar. Prior to surgery, a radiologist often first marks the lump with a wire, making it easier for the surgeon to find.

Illustration

Large cell carcinoma - Illustration Thumbnail

Large cell carcinoma

Non-small cell carcinomas are the most common lung cancers.

Illustration

Prostate cancer - Illustration Thumbnail

Prostate cancer

Treatment of prostate cancer varies depending on the stage of the cancer (i.e., spread) and may include surgical removal, radiation, chemotherapy, hormonal manipulation or a combination of these treatments.

Illustration

Pap smears and cervical cancer - Illustration Thumbnail

Pap smears and cervical cancer

An instrument called a speculum holds the walls of the vagina open so that the cervix may be viewed and a swab of cells obtained for analysis.

Illustration

Colon cancer - series - Presentation Thumbnail

Colon cancer - series

Presentation

 
Lung cancer

Lung cancer

Animation

Breast cancer

Breast cancer

Animation

Cervical cancer

Cervical cancer

Animation

Colon cancer

Colon cancer

Animation

Prostate cancer

Prostate cancer

Animation

Open biopsy of the breast - Illustration Thumbnail

Open biopsy of the breast

An open biopsy can be performed under local or general anesthesia and will leave a small scar. Prior to surgery, a radiologist often first marks the lump with a wire, making it easier for the surgeon to find.

Illustration

Large cell carcinoma - Illustration Thumbnail

Large cell carcinoma

Non-small cell carcinomas are the most common lung cancers.

Illustration

Prostate cancer - Illustration Thumbnail

Prostate cancer

Treatment of prostate cancer varies depending on the stage of the cancer (i.e., spread) and may include surgical removal, radiation, chemotherapy, hormonal manipulation or a combination of these treatments.

Illustration

Pap smears and cervical cancer - Illustration Thumbnail

Pap smears and cervical cancer

An instrument called a speculum holds the walls of the vagina open so that the cervix may be viewed and a swab of cells obtained for analysis.

Illustration

- Presentation Thumbnail

Colon cancer - series

Presentation

 

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