CancerCarcinoma; Malignant tumor
Cancer is the uncontrolled growth of abnormal cells in the body. Cancerous cells are also called malignant cells.
Cancer grows out 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:
- Benzene and other chemical exposures
- Drinking too much alcohol
Beer, wine, and liquor all contain alcohol. Drinking an excessive amount of alcohol can put you at risk for alcohol-related problems.Read Article Now Book Mark Article
- Environmental toxins, such as certain poisonous mushrooms and a type of mold that can grow on peanut plants and produce a toxin called aflatoxin
Aflatoxins are toxins produced by a mold (fungus) that grows on nuts, seeds, and legumes.Read Article Now Book Mark Article
- Genetic problems
- Radiation exposure
- Too much sunlight exposure
The cause of many cancers remains unknown.
The most common cause of cancer-related death is lung cancer.
In the United States, skin cancer is the most commonly diagnosed cancer.
In US men, other than skin cancer, the three most common cancers are:
- Prostate cancer
Prostate cancer is cancer that starts in the prostate gland. The prostate is a small, walnut-shaped structure that makes up part of a man's reproduc...Read Article Now Book Mark Article
- Lung cancer
Small cell lung cancer (SCLC) is a fast-growing type of lung cancer. It spreads much more quickly than non-small cell lung cancer. There are two typ...Read Article Now Book Mark Article
- Colorectal cancer
Colorectal cancer is cancer that starts in the large intestine (colon) or the rectum (end of the colon). Other types of cancer can affect the colon. ...Read Article Now Book Mark Article
In US women, other than skin cancer, the three most common cancers are:
- Breast cancer
Breast cancer is cancer that starts in the tissues of the breast. There are two main types of breast cancer:Ductal carcinoma starts in the tubes (du...Read Article Now Book Mark Article
- Lung cancer
- Colorectal cancer
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.
Stomach cancer is cancer that starts in the stomach.Read Article Now Book Mark Article
Some other types of cancer include:
- Brain cancer
A primary brain tumor is a group (mass) of abnormal cells that start in the brain.Read Article Now Book Mark Article
- Cervical cancer
Cervical cancer is cancer that starts in the cervix. The cervix is the lower part of the uterus (womb) that opens at the top of the vagina.Read Article Now Book Mark Article
- Hodgkin lymphoma
Hodgkin lymphoma is a cancer of lymph tissue. Lymph tissue is found in the lymph nodes, spleen, liver, bone marrow, and other sites.Read Article Now Book Mark Article
- Kidney cancer
Renal cell carcinoma is a type of kidney cancer that starts in the lining of very small tubes (tubules) in the kidney.Read Article Now Book Mark Article
Leukemia is a type of blood cancer that begins in the bone marrow. Bone marrow is the soft tissue in the center of the bones, where blood cells are ...Read Article Now Book Mark Article
- Liver cancer
Hepatocellular carcinoma is cancer that starts in the liver.Read Article Now Book Mark Article
- Non-Hodgkin lymphoma
Non-Hodgkin lymphoma (NHL) is cancer of the lymph tissue. Lymph tissue is found in the lymph nodes, spleen, and other organs of the immune system. W...Read Article Now Book Mark Article
- Ovarian cancer
Ovarian cancer is cancer that starts in the ovaries. The ovaries are the female reproductive organs that produce eggs.Read Article Now Book Mark Article
- Pancreatic cancer
Pancreatic cancer is cancer that starts in the pancreas.Read Article Now Book Mark Article
- Testicular cancer
Testicular cancer is cancer that starts in the testicles. The testicles are the male reproductive glands located in the scrotum.Read Article Now Book Mark Article
- Thyroid cancer
Thyroid cancer is a cancer that starts in the thyroid gland. The thyroid gland is located inside the front of your lower neck.Read Article Now Book Mark Article
- Uterine cancer
Endometrial cancer is cancer that starts in the endometrium, the lining of the uterus (womb).Read Article Now Book Mark Article
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:
- Loss of appetite
- Night sweats
- 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:
- Biopsy of the tumor
A biopsy is the removal of a small piece of tissue for laboratory examination.Read Article Now Book Mark Article
- Blood tests (which look for chemicals such as tumor markers)
- Bone marrow biopsy (for lymphoma or leukemia)
Bone marrow biopsy
A bone marrow biopsy is the removal of marrow from inside bone. Bone marrow is the soft tissue inside bones that helps form blood cells. It is foun...Read Article Now Book Mark Article
- Chest x-ray
A chest x-ray is an x-ray of the chest, lungs, heart, large arteries, ribs, and diaphragm.Read Article Now Book Mark Article
- Complete blood count (CBC)
Complete blood count
A complete blood count (CBC) test measures the following:The number of white blood cells (WBC count)The number of red blood cells (RBC count)The numb...Read Article Now Book Mark Article
- CT scan
A computed tomography (CT) scan is an imaging method that uses x-rays to create pictures of cross-sections of the body. Related tests include:Abdomin...Read Article Now Book Mark Article
- Liver function tests
Liver function tests
Liver function tests are common tests that are used to see how well the liver is working. Tests include:AlbuminAlpha-1 antitrypsinAlkaline phosphata...Read Article Now Book Mark Article
- MRI scan
A magnetic resonance imaging (MRI) scan is an imaging test that uses powerful magnets and radio waves to create pictures of the body. It does not us...Read Article Now Book Mark Article
- PET scan
A positron emission tomography (PET) scan is a type of imaging test. It uses a radioactive substance called a tracer to look for disease in the body...Read Article Now Book Mark Article
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 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 tumor 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 the cancer. This is often the case with skin cancers, as well as cancers of the lung, breast, and colon.
- If the tumor has spread to local lymph nodes only, sometimes these can also be removed.
- 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.
Radiation therapy uses high-powered radiation (such as x-rays or gamma rays), particles, or radioactive seeds to kill cancer cells.Read Article Now Book Mark Article
The term chemotherapy is used to describe cancer-killing drugs. Chemotherapy may be used to:Cure the cancerShrink the cancerPrevent the cancer from ...Read Article Now Book Mark Article
Immunotherapy is a type of cancer treatment that relies on the body's infection-fighting system (immune system). It uses substances made by the body...Read Article Now Book Mark Article
Targeted cancer therapies
Targeted therapy uses drugs to stop cancer from growing and spreading. It does this with less harm to normal cells than other treatments. Standard ...Read Article Now Book Mark Article
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 right.
- Get plenty of rest, and don't feel like you have to accomplish tasks all at once.
- Avoid people with colds or the flu. 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.
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 cancer patients.
The following organizations are good resources for information on cancer:American Cancer Society -- www. cancer. orgAmerican Childhood Cancer Organiz...Read Article Now Book Mark Article
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 tumors are quickly life threatening.
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.
You can reduce the risk of getting a cancerous (malignant) tumor by:
- Eating healthy foods
- Exercising regularly
- Limiting alcohol
- 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. Some people at high risk for developing certain cancers can take medicines to reduce their risk.
A mammogram is an x-ray picture of the breasts. It is used to find breast tumors and cancer.Read Article Now Book Mark Article
A colonoscopy is an exam that views the inside of the colon (large intestine) and rectum, using a tool called a colonoscope. The colonoscope has a sm...Read Article Now Book Mark Article
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, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 169.
National Cancer Institute website. Chemotherapy and you: support for people with cancer. www.cancer.gov/publications/patient-education/chemo-and-you. Updated September 2018. Accessed May 12, 2021.
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 May 12, 2021.
Siegel RL, Miller KD, Jemal A. Cancer statistics, 2019. CA Cancer J Clin. 2019;69(1):7-34. PMID: 30620402 pubmed.ncbi.nlm.nih.gov/30620402/.
- Melanoma and other skin cancers(In-Depth)
- Colon and rectal cancers(In-Depth)
- Cervical cancer(In-Depth)
- Prostate cancer(In-Depth)
- Non-small cell lung cancer(In-Depth)
- Breast cancer(In-Depth)
- Ovarian cancer(In-Depth)
- Colorectal cancer(Alt. Medicine)
- Brain cancer(Alt. Medicine)
- Skin cancer(Alt. Medicine)
Review Date: 1/17/2021
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.