Diagnosis of Breast Cancer

Mammogram

A mammogram is an x-ray of the breast. It can often find tumors that are too small for you or your doctor to feel. The accuracy of a mammogram to detect cancer will depend on several factors. It may be affected by the size of the tumor, your age, breast density, and the skill of the radiologist. Although mammograms are the most sensitive test currently used to evaluate the breast, they will miss 10%-15% of breast cancers.

Other imaging tests, including MRIs, are being studied to see if they are more sensitive than mammograms.

During ultrasonography, sound waves (called ultrasound) are bounced off tissues. The echoes are converted into a picture. Ultrasound is used to evaluate lumps that have been identified through breast self-exam, clinical breast exam, or mammography. They help to see if a mass is solid or has liquid in it. Solid masses are generally more concerning than cystic or liquid-filled masses.

Ultrasonography

Further Testing

Your doctor will use these tests to help determine the next step. Your doctor may simply continue to monitor you for any future breast changes. Your doctor may also decide to do further testing. In some cases, your doctor may decide to remove a sample of tissue. The sample will be sent to a lab. This sample may be taken by one of the following methods:

• Fine needle aspiration —A thin needle is used to remove fluid and/or cells from a breast lump. If the fluid is clear, it may not be checked by a lab.
• Large needle (or core) biopsy—tissue from a suspicious area is removed with a special needle.
• Surgical biopsy —During a surgical biopsy, all or part of a breast lump is removed for lab examination. An incisional biopsy removes a small portion of a large lump, while an excisional biopsy removes the entire lump (usually small).

Keep in mind that your doctor may recommend proceeding directly to biopsy if the lump is clinically suspicious. The only way to absolutely confirm the diagnosis of breast cancer is by tissue examination.

Staging

If cancer is found, your prognosis and treatments depend on the location, size, and stage of the cancer.

The following tests may be done to determine the stage:

• CT scan of the chest and abdomen
• Bone scan
• Sentinel lymph node biopsy
• PET/CT—to help detect distant spread of tumor, especially for locally advanced disease

To determine the stage, the doctor uses the following classification system:

• Stage 0—Called "in situ" (within the site of origin), the cancer remains in the breast and has not spread.
• Stage I—Cancer has spread beyond the lobe or duct and invaded nearby tissue. At this stage, the tumor is no larger than two centimeters in size and has not spread beyond the breast.
• Stage II—Stage II means one of the following:
  • Tumor in the breast is less than two centimeters in size and the cancer has spread to the lymph nodes under the arm, or
  • Tumor is between two and five centimeters in size (with or without spread to the lymph nodes under the arm) or
  • Tumor is larger than five centimeters but has not spread to the lymph nodes under the arm
• Stage III—The tumor is large (more than five centimeters in size) and the cancer has spread to the lymph nodes. Additionally, the tumor could invade the skin, the chest wall, the nipple, or spread to the lymph nodes in the neck or chest wall (called internal mammary nodes).
• Stage IV—Cancer has spread beyond the breast and lymph nodes to other parts of the body.

In addition to staging, other factors play a role in your prognosis, including your general health and age. In a large study, for example, younger women (less than age 40), who were initially diagnosed with Stage I or II breast cancer, had lower survival rates compared to older patients. Researchers are investigating what may account for this unexpected result.