How Is Breast Cancer Diagnosed?
It is important to remember that a lump or other changes in the breast, or an abnormal area seen on a mammogram, may be caused by cancer or, more often, by other, less serious problems.
To determine the cause of any signs or symptoms you may have, your doctor will perform a careful physical exam that includes a personal and family medical history, as well as questions about your current overall health status. An examination that includes the following will also be done:
Palpation. Carefully feeling the lump and the tissue around it — its size, its texture, and whether it moves easily. Benign lumps often feel different from cancerous ones.
Nipple discharge examination. Fluid may be collected from spontaneous nipple discharge and then sent to the lab to look for cancer cells. Most nipple secretions are not cancer, as an injury, infection, or benign tumor may cause discharge. For women who are at high risk for breast cancer, a procedure called ductal lavage may be used. Ductal lavage is a procedure that collects cells from inside the milk ductal system — the location where most breast cancers begin.
In addition to a physical examination by your doctor, imaging tests will be performed. Imaging tests may include one or more of the following:
Diagnostic mammography. A diagnostic mammogram is an X-ray of the breast used to diagnose unusual breast changes, such as a lump, pain, nipple thickening or discharge, or a change in breast size or shape. A diagnostic mammogram is also used to look closely at changes detected on a screening mammogram. More pictures are taken for a diagnostic mammogram than for a screening mammogram. It is a basic medical tool and is part of the workup of breast changes, regardless of a woman's age.
Digital mammography (also called full-field digital mammography, or FFDM). A type of mammogram in which the images are electronically captured and stored on a computer rather than X-ray film. The images are viewed on a computer screen.
Images can be changed, such as the degree of magnification, brightness, or contrast, to help visualization. They can also be shared and stored electronically. Studies are being done to see which type of mammography will be of more benefit to women for the long term. Some studies have found FFDM to be more accurate in finding cancers in women younger than 50. Also, it has been found that women undergoing digital mammography do not have to return for additional studies as often as with standard mammography because the digital images have fewer questionable spots needing more investigation. However, not all hospitals and mammography facilities have digital equipment available. Still, women should not miss their regular mammogram if a digital mammogram is not available.
Ultrasound. This test uses high-frequency sound waves, not heard by humans, to get images of body tissues. The sound waves enter the breast and bounce back. The pattern of their echoes produces a picture called a sonogram, which is displayed on a screen. This exam is often used along with mammography.
Scintimammography. A specialized radiology procedure sometimes used to assess the breasts when other examinations have not been clear. Scintimammography, or a molecular breast scan, is a type of nuclear radiology procedure. This means that a tiny amount of a radioactive substance is used during the procedure to assist in the examination of the breasts. The radioactive substance, called a radionuclide (radiopharmaceutical or radioactive tracer), is absorbed by certain types of body tissues. the exact role of scintimammography is unclear at this time.
Magnetic resonance imaging (MRI). A diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body. According to the ACS, contrast-enhanced MRI of the breasts has been shown to have a high sensitivity for detecting breast cancer in women both with or without symptoms. MRI scans along with annual mammograms should be considered for the following:
Women with BRCA1 or BRCA2 mutation
Women with a first-degree relative (mother, sister, and/or daughter) with a BRCA1 or BRCA2 mutation, if they have not yet been tested for the mutation
Women with a 20% to 25% or greater lifetime risk of breast cancer, based on one of several accepted risk assessment tools that look at family history and other factors
Women who were treated with radiation therapy to the chest area between the ages of 10 years and 30 years
Women with Li-Fraumeni syndrome, Cowden syndrome, or Bannayan-Riley syndrome, or who may have the syndrome based on a history of the syndrome in a first-degree relative
It is recommended that high-risk women begin screening mammography and screening MRI at the age of 30, unless they and their doctors agree that a different age is more appropriate.
Based on these exams, your doctor may decide that no further tests are needed and no treatment is necessary. In such cases, your doctor may want to check you regularly to watch for any changes.
Often, however, the doctor must remove fluid or tissue from the breast to be sent to the lab to look for cancer cells. The procedure is called a biopsy. It can be done using a needle to get a piece of the area of concern, or it can be done with surgery.
A biopsy removes tissue or cells from the body for examination under a microscope. It is the only way to know for sure if cancer or other abnormal cells are present. Without a biopsy and subsequent pathology, there is no definite diagnosis.
Biopsies may be done under local or general anesthesia. Local anesthesia means drugs are used to numb the area of the breast that the needle will be put into. General anesthesia means you will be given drugs to put you into a deep sleep while the biopsy is being done. There are several types of breast biopsy procedures. The type of biopsy done will depend on the location and size of the breast lump or abnormality.
Types of breast biopsy procedures include, but are not limited to, the following:
Fine needle aspiration biopsy. A very thin needle is placed into the lump or suspicious area to remove a small sample of fluid and/or tissue. No incision (cut) is necessary. A fine needle aspiration biopsy may be used to help find out if a breast change is a cyst (a fluid-filled sac that's usually not cancer) or a lump.
Core needle biopsy. A large needle is guided into a lump or suspicious area to remove a small cylinder of tissue (also called a core). No incision is necessary.
Surgical biopsy (also called an open biopsy). A surgeon removes part or all of a lump or suspicious area through an incision into the breast. There are 2 types of surgical biopsies. During an incisional biopsy, a small part of the lump is removed; whereas during an excisional biopsy, the entire lump is removed. In some cases, if the breast lump is very small and deep and is difficult to locate, the wire localization technique may be used during surgery. With this technique, a special wire is placed into the lump under X-ray guidance. The surgeon then follows this wire to help locate the breast lump.
There are special instruments and techniques that may be used to guide the needles and to assist with biopsy procedures. These include, but are not limited to, the following:
Stereotactic biopsy. Stereotactic biopsy finds the exact location of a breast lump or suspicious area by using a computer and mammogram results to create a three-dimensional (3D) picture of the breast. A sample of tissue is removed with a needle.
Mammotome breast biopsy system or ATEC (Automated Tissue Excision and Collection) (also called vacuum-assisted biopsy). A type of hollow tube is inserted into the breast lump or mass. The breast tissue is gently suctioned into the tube, and a rotating knife inside the tube removes the tissue.
Ultrasound-guided biopsy. A technique that uses a computer and a transducer that sends out ultrasonic sounds waves to create images of the breast lump or mass. This technique helps to guide the needle biopsy.
A procedure, called sentinel node biopsy, is used to see if cancer cells have spread to the lymph nodes. This surgical procedure may be done sometime after the biopsy during the initial diagnostic period to aid in staging of the breast cancer. This procedure involves injecting a dye and/or radioactive substance into the tumor. This injection helps to locate the lymph node that the tumor drains into first (the sentinel node) — the one that is most likely to have cancer cells present if the cancer has spread. The surgeon removes the lymph node that absorbs the dye and radioactive substance and sends it to the pathologist to examine closely for the presence of cancer cells.