Breast cancer starts when abnormal cells develop and grow uncontrollably in the breast tissue. The outcome is different for each woman, so early detection is critical.

The American Cancer Society outlines specific recommendations for breast cancer screenings, with annual mammograms beginning at age 45 (or sooner if you have a family history of breast cancer).

If you’re younger and don’t need annual mammograms, it’s still important to conduct self-breast examinations on a monthly basis. This can aid you in detecting changes in your breasts, such as lumps, dimpling, an inverted nipple, or redness. Your doctor may also conduct a clinical breast examination at annual checkups.

Different diagnostic tests help to diagnose and detect breast cancer early. Read on to learn more about these tests.

Annual mammograms are recommended for women age 45 and older, but you can begin screenings as early as 40. A mammogram is an X-ray that only takes pictures of the breasts. These images help doctors identify abnormalities in your breast such as masses, which could indicate cancer.

Keep in mind that an abnormality on your mammogram doesn’t necessarily mean you have breast cancer, but you may need further testing.

An ultrasound is a test that uses sound waves to produce images of the inside of your body. If your mammogram detects a mass, your doctor may order an ultrasound to identify the mass. Your doctor may also order an ultrasound if there’s a visible lump on your breast.

Ultrasounds help doctors determine whether a lump or mass is a fluid or a solid. A fluid-filled mass indicates a cyst, which is noncancerous.

To perform a breast ultrasound, your doctor places gel on your breast and uses a special instrument to create an image of your breast tissue.

A biopsy removes a sample of tissue from a lump or mass to determine whether it’s cancerous or benign. This is usually an outpatient surgical procedure.

There are several ways to perform a breast biopsy, depending on the size of the tumor. If the tumor is small and not very suspicious, a surgeon may conduct a needle biopsy. The surgeon inserts the needle into your breast and removes a sample piece of tissue. You may need a surgical biopsy for a larger lump. This removes all or part of the lump. The surgeon may also remove any enlarged lymph nodes.

These biopsies together form the gold standard for tissue evaluation:

Fine-needle aspiration biopsy is used when the lump is solid. The doctor inserts a thin needle and retracts a tiny piece of tissue for study by a pathologist. In some cases, the doctor may want to examine a suspected cystic lump to confirm that there is no cancer in a cyst.

Core needle biopsy involves using a larger needle and tube to extract a sample of tissue up to the size of a pen. The needle is guided by feel, mammography, or ultrasound. A computerized version that is gaining popularity for its accuracy is called stereotactic breast biopsy.

Surgical (or “open”) biopsy is when a surgeon removes part (incisional biopsy) or all (excisional biopsy, wide local excision, or lumpectomy) of a lump for evaluation under a microscope. If the lump is small or hard to locate by touch, the surgeon may use a procedure called stereotactic wire localization to map out a route to the mass prior to the surgery.

Sentinel node biopsy: A sentinel node biopsy is a biopsy from a lymph node where cancer is most likely to spread first. In the case of breast cancer, a sentinel node biopsy is usually taken from lymph nodes in the axilla, or armpit region. This test is used to help determine the presence of cancer and how far it has spread.

Image-guided biopsy: Foran image-guided biopsy, a doctor uses an imaging technique, like an ultrasound, to create a real-time image of a suspicious area that can’t be easily seen or felt through your skin. Your doctor will use this image to help guide a needle to the best spot for collecting suspicious cells.

Analysis of these biopsies can help your doctor determine the grade of your cancer, the tumor’s features, and how your cancer will respond to certain treatments.

A breast MRI scan isn’t a typical screening tool for breast cancer because of its higher risk for false positives. But if you have risk factors for breast cancer, as a precaution your doctor may recommend MRI screenings with your annual mammograms.

This test uses a magnet and radio waves to produce a picture of the inside of your breasts.

After you’re diagnosed with breast cancer, the next step is identifying your stage. Knowing the stage is how your doctor determines the best course of treatment. Staging depends on the size of the tumor and whether it has spread outside your breast. The disease is categorized into five stages:

  • Stage 0: Cancer hasn’t spread to other organs or tissue.
  • Stage 1: The tumor is up to 2 centimeters (cm) and hasn’t spread to the lymph nodes.
  • Stage 2: The tumor is between 2 and 5 cm. The cancer has spread to surrounding lymph nodes in the breast.
  • Stage 3: The tumor is more than 5 cm in diameter, and cancer has spread to other lymph nodes or nearby tissue.
  • Stage 4: Cancer has spread to other parts of the body.

Cancer cells that spread to lymph nodes can travel to different parts of your body. During the staging process, your doctor may order a complete blood count and perform a mammogram of your other breast to check for signs of a tumor. Your doctor may also use any of the following tests to determine the extent of your cancer as well as to assist with diagnosis:

Bone scan: Metastasized cancer can spread to the bones. A bone scan allows your doctor to check your bones for evidence of cancerous cells.

CT scan: This is another type of X-ray for creating detailed images of your organs. Your doctor may use a CT scan to see if cancer has spread to your chest or stomach area.

MRI scan: Although this imaging test isn’t a typical cancer screening tool, it’s effective for staging breast cancer. An MRI creates digital images of different parts of your body. It can help your doctor determine whether cancerous cells have spread to your spinal cord, brain, and other organs.

PET scan: A PET scan is a unique test. Your doctor injects a dye into your vein. As the dye travels through your body, a special camera produces three-dimensional images of the inside of your body. This helps your doctor identify the location of tumors.

Getting a second opinion during your cancer care process is very common. It’s a good idea to get your second opinion before starting treatment, because a second opinion can alter your diagnosis and thus your treatment. However, you can get a second opinion at any point during your treatment.

Some common points during your cancer care to ask for a second opinion include:

  • after your pathology report is complete
  • before surgery
  • while planning treatments following surgery
  • during treatment if you believe there may be a reason to change the course of your treatment
  • after completing treatment, especially if you didn’t ask for a second opinion prior to starting treatment

If your mammogram or clinical examination raises concerns, make sure you follow up with other diagnostic tests. Breast cancer is treatable, but it can also be life-threatening if not detected early.

Talk to your doctor for information on annual screening, especially if you have a personal or family history of breast cancer. Regardless of your age, make sure you complete breast self-exams every month.