Key Points about Carcinoma in Situ

  • Carcinoma in situ is cancer that has not spread beyond its original site.
  • This type of cancer can occur throughout the body.
  • Doctors use biopsy, imaging tests and physical exam to diagnose carcinoma in situ.
  • Treatment for carcinoma in situ may include surgery, chemotherapy, hormone therapy and/or radiation therapy.


Carcinoma in situ is a type of cancer that occurs when the cancerous cells have not spread beyond the original site of cancer (non-invasive cancer). Carcinoma in situ is also known as stage 0 disease. Carcinoma in situ can occur in different areas throughout the body. Types of carcinoma in situ that occur in the breast are ductal carcinoma in situ (DCIS) and lobular carcinoma.

Carcinoma in situ causes

Carcinoma in situ is caused by mutations (changes) to the DNA of cells. 

Carcinoma in situ risk factors

The following factors may increase your risk for developing carcinoma in situ:

  • Being older
  • Having a family history of cancer
  • Having a personal history of cancer

Carcinoma in situ symptoms

Many people with carcinoma in situ won’t experience any symptoms. When they do occur, they can include:

  • A lump that can be felt with the fingers
  • Fatigue
  • Unexplained weight loss

Carcinoma in situ diagnosis

Your oncologist may use one or more of the following tests to diagnose this condition:

  • Physical exam – your doctor will perform a complete physical exam, including asking questions about your health history, symptoms and related risk factors.
  • Computerized tomography (CT) scan – this type of imaging test provides a 3-D image of the inside of the body that your doctor can use to determine if there is any cancer present.
  • Biopsy – in this test, your doctor removes a biopsy (small tissue sample) from the suspicious area. This sample is sent to the laboratory, where a specialist closely checks the biopsy for abnormalities.
  • Magnetic resonance imaging (MRI) – this type of imaging test uses high-powered magnets to create detailed images of the inside of your body. Your doctor can closely examine these images to look for any areas that could indicate cancer.

Carcinoma in situ treatments

Depending on your personal health history, the extent of your carcinoma in situ and other factors, your oncologist may recommend one or more of the following treatment options:

  • Surgery – in most cases, your doctor will recommend a surgical procedure to remove the cancerous area. Your surgeon will work to preserve as much surrounding healthy tissue as possible. In some cases, you may opt to undergo reconstructive surgery following surgery to treat carcinoma in situ.
  • Chemotherapy – you may need to undergo chemotherapy to destroy any cancerous cells that couldn’t be removed surgically. During this treatment, medication is used to destroy cancerous cells. Chemotherapy can be taken via an oral (by mouth) pill or intravenously (through a vein).
  • Radiation therapy – this treatment uses high-powered energy beams to destroy cancerous cells. You may need to undergo radiation therapy to destroy any cancerous cells that couldn’t be removed surgically.

When should I seek care?

If you experience any of these symptoms, start by voicing your concerns and symptoms to your primary care provider. From there, your doctor may suggest seeing an oncologist for more specialized treatment.

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