Breast cancer is the second most common type of cancer diagnosed and also the second highest cause of death due to cancer among women. Breast cancer can also affect men, but it is rarely seen. If diagnosed in time, it can be treated and cured. To confirm a diagnosis of breast cancer, doctors may use many tools:

• Breast exam
  The doctor will manually check the breasts and the lymph nodes in the armpits for the presence of any lumps or abnormalities. A breast exam can be conducted by an individual themselves as well.
• Mammogram
  A mammogram is an X-ray of the breast. If any abnormalities are seen on this mammogram, further tests may be recommended.
• Breast ultrasound
  This involves projecting sound waves toward the breasts to produce images of the tissues inside. This is often used after a lump has been detected to check whether it is filled with fluid or is a solid cyst.
• Biopsy
  A tissue biopsy is the only conclusive way of confirming a breast cancer diagnosis. A special needle is guided by an imaging device to the suspicious area to extract a tissue sample. This sample is then tested in a laboratory to check whether the mass is cancerous. A biopsy may also be used to find out the type of cells affected by cancer and to grade the aggressiveness of cancer.
• Breast Magnetic Resonance Imaging (MRI)
  An MRI involves the use of radio waves and magnets to create images of the breast tissue. Before this procedure, a dye is injected into the patient. This dye moves through the blood vessels in the breast to make the structure more clearly visible.

In addition to these tests, many other tests may also be undertaken depending on the patient’s overall health and situation.

Staging breast cancer
Once the diagnosis has been confirmed, the doctor must understand what stage cancer has reached to be able to treat it. Breast cancer can be categorized in multiple stages ranging from stage 0 to stage IV, the latter being the most advanced stage, where cancer would have spread to other parts of the body as well. Staging for breast cancer also takes into account other aspects of cancer such as the presence or absence of tumor markers, proliferation factors, estrogen and progesterone levels, and more.

In many cases, a doctor may not fully understand the stage at which cancer is until surgery is performed to remove the tumor. The tests and procedures used to determine the stage of breast cancer include:

• A complete blood count and other blood tests
• A mammogram of the affected breast
• An MRI of the breast
• Bone scan
• Positron Emission Tomography (PET) scan
• Computerized Tomography (CT) scan

These tests are not always required. The doctor will advise the patient as to which tests are necessary based on the symptoms. It is only after the stage at which cancer is has been known that a doctor will be able to determine the best form of treatment.