Key Points about Invasive Ductal Carcinoma (IDC)

  • Invasive ductal carcinoma is the most common type of breast cancer.
  • “Invasive” means that the cancer has spread beyond the initial site of the cancer, a milk duct of the breast.
  • Doctors use biopsy, imaging tests and physical exam to diagnose invasive ductal carcinoma.
  • Treatment for invasive ductal carcinoma may include surgery, chemotherapy, hormone therapy and/or radiation therapy.


Invasive ductal carcinoma is a type of breast cancer that begins in the milk ducts of the breast and then spreads beyond it. Also known as IDC, this is the most common type of breast cancer and comprises 80 percent of all breast cancer cases.

Invasive ductal carcinoma causes

Invasive ductal carcinoma is caused by mutations (changes) to the DNA of milk duct cells in the breast.

Invasive ductal carcinoma risk factors

Being over age 55 can increase a person’s risk for developing invasive ductal carcinoma.

Invasive ductal carcinoma symptoms

In its early stages, invasive ductal carcinoma often does not cause any symptoms. When they do occur, signs and symptoms of this type of breast cancer may include:

  • A lump or mass on the breast or in the underarm area that can be felt
  • Changes in the skin of the breast, such as redness or swelling
  • Itchiness in the breast
  • Pain in the breast
  • Unusual nipple discharge
  • Warmth or irritation in the breast

Invasive ductal carcinoma 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. Your doctor may also use a CT scan to stage (determine the degree) of IDC.
  • 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.
  • Mammogram – this type of specialized X-ray creates images of the inside of the breasts. Mammograms are used as routine screening tests, but they may also be performed when a woman has symptoms of breast cancer.

Invasive ductal carcinoma treatment

Depending on your personal health history, the extent of your invasive ductal carcinoma 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. Types of surgery include lumpectomy (removal of the cancerous cells and a margin of healthy tissue) and mastectomy (removal of an entire breast). 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 breast cancer.
  • 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).
  • Hormone therapy – if you have hormone receptor-positive breast cancer, your oncologist may recommend you undergo hormone therapy for the hormones estrogen and progesterone.
  • Immunotherapy – in this type of treatment, medications trigger the body’s immune system to fight the cancer.
  • 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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