Breast Cancer Diagnosis

About Breast Cancer

Making the right diagnosis is a critical component of successful cancer treatment. Penn's cancer specialists have wide-ranging experience treating all forms of breast cancer, including those that occur only rarely. Their expert understanding of the disease allows them to create cancer treatment plans that are customized for every patient.

Breast cancer, the uncontrolled growth of cells in the breast, is the most common type of cancer among women, excluding skin cancer. Breast cancer forms in the tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare.

Read more About Breast Cancer Treatment at Penn Medicine

Breast Cancer Diagnosis

Doctors at Penn Medicine believe that early detection tests for breast cancer save many thousands of lives each year, and that many more lives could be saved if even more women took advantage of these tests.


Breast Cancer Screening

Following the guidelines for early detection improves the chances that breast cancer can be diagnosed at an early stage and treated successfully. The American Cancer Society recommends:

  • Screening mammograms annually for women age 40 and older.
  • Clinical breast exam (CBE) for women in their 20s and 30s as part of a regular exam by a health professional, at least every three years. After age 40, women should have a breast exam by a health professional every year.
  • Breast self exam (BSE) is an option for all women starting as early as in their 20s.
  • Annual mammogram and breast MRI for women at high risk for breast cancer.

The goal of breast cancer screenings, such as mammograms, is to find breast cancers before they spread. Breast cancers that can be felt tend to be larger and are more likely to have already spread beyond the breast. Breast cancers found during screening exams are more likely to be small and still confined to the breast. The size of a breast cancer and how far it has spread are important factors in predicting the prognosis for women with breast cancer.
Women at high risk (greater than 20 percent lifetime risk based on family history) should get an MRI and a mammogram every year. Women at moderately increased risk (15 to 20 percent lifetime risk based on family history) should talk with their doctors about the benefits and limitations of adding MRI screening to their yearly mammogram. Yearly MRI screening is not recommended for women whose lifetime risk of breast cancer is less than 15 percent.

MRI screening is done in addition to a screening mammogram. Although an MRI is a more sensitive test, it can return false positive results or miss some cancers that a mammogram does detect.

For most women at high risk, screening with MRI and mammograms should begin at age 30 years and continue for as long as a woman is in good health. Because the evidence is limited regarding the best age at which to start screening, this decision should be based on shared decision-making between patients and their health care providers, taking into account personal circumstances and preferences.

If something suspicious is found during a screening exam, one or more breast tools can help doctors find out if breast cancer is present. If cancer is confirmed, the stage of the cancer is then determined. Staging refers to how far the cancer has spread to nearby tissue or organs.

Breast Cancer Diagnostic Tools

If something suspicious is found during a screening exam, physicians at Penn Medicine will use one or more of the following tests to find out if breast cancer is present. Tests include:

  • Medical history and physical exam. The breasts are thoroughly examined for any lumps or suspicious areas and to feel their texture, size, and relationship to the skin and chest muscles. Any changes in the nipples or the skin of the breasts will be noted. The lymph nodes in the armpit and above the collarbones may be palpated, because enlargement or firmness of these lymph nodes might indicate spread of breast cancer.
  • Imaging tests. Pictures of the inside of the body can help find out whether a suspicious area might be cancerous, to learn how far cancer may have spread, and to help determine if treatment is working.
  • Diagnostic mammograms. Although mammograms are mostly used for screening, they can also be used to examine the breast of a woman who has a breast problem. This can be a breast mass, nipple discharge, or an abnormality that was found on a screening mammogram. In some cases, special images known as magnification views are used to make a small area of abnormal breast tissue easier to evaluate.
  • Digital mammograms. Digital mammograms are the same as standard mammograms in that X-rays are used to produce an image of the breast. The differences are in the way the image is recorded, viewed by the doctor, and stored. Standard mammograms are recorded on large sheets of photographic film. Digital mammograms are recorded and stored on a computer. After the exam, the doctor can look at them on a computer screen and adjust the image size, brightness, or contrast to see certain areas more clearly. Digital images can also be sent electronically to another site for a remote consult with breast specialists. All of Penn's imaging facilities use digital mammography.
  • Computer-aided detection and diagnosis (CAD). Over the past two decades, CAD has been developed to help radiologists detect suspicious changes on mammograms. This can be done with standard film mammograms or with digital mammograms.
  • Magnetic resonance imaging (MRI) of the breast. MRI scans use radio waves and strong magnets instead of X-rays. It's important that MRI scans of the breast be done on an MRI machine specially adapted for breast views.
  • Breast ultrasound. Uses sound waves to image the breast. This test is painless and does not expose patients to radiation. It is used primarily to target a specific area of concern found on a mammogram or a lump found during a physical exam.
  • Biopsy. A sample of the suspicious area is removed and viewed under a microscope when mammograms and other tests find a breast change that is possibly cancer. A biopsy is the only way to tell if cancer is really present.

Diagnostic Surgery/Biopsy

A biopsy is a diagnostic surgical procedure in which a tiny bit of the breast tumor is removed and examined under a microscope.

Penn Medicine surgeons perform several different types of biopsies based the amount of tissue being removed. Some biopsies use a very fine needle, while others use thicker needles or even require a small surgical procedure to remove more tissue. The breast cancer team decides which type of biopsy to use depending on the particular breast mass.

  • Fine needle aspiration biopsy. Fine needle aspiration (FNA) is the least invasive method of biopsy and it usually leaves no scar. An injection of local anesthesia numbs the breast before the surgeon or radiologist uses a thin needle with a hollow center to remove a sample of cells from the suspicious area. In many cases, the doctor can feel the lump and guide the needle to the right place. If the lump cannot be felt, imaging studies such as ultrasound or mammogram are used to guide the needle to the right location.
  • Core needle biopsy. Core needle biopsy uses a larger hollow needle than fine needle aspiration does to remove several cylinder-shaped samples of tissue from the suspicious area. This type of biopsy is frequently called a vacuum-assisted core biopsy. In most cases, the needle is inserted about three to six times so that the doctor can get enough samples. If the lesion cannot be felt through the skin, the surgeon or radiologist can use an image-guided technique such as ultrasound-guided biopsy or stereotactic needle biopsy. A small metal clip may be inserted into the breast to mark the site of biopsy in case the tissue proves to be cancerous and additional surgery is required. This clip is left inside the breast and is not harmful to the body. If the biopsy leads to more surgery, the clip will be removed at that time. If no cancer is found, the clip serves as a sign in future mammograms that tells the radiologist a breast biopsy was performed.
  • Incisional biopsy. Incisional biopsy is more like regular surgery, in which the surgeon uses a scalpel to remove a piece of the tissue for examination. The doctor may recommend incisional biopsy if a needle biopsy is inconclusive or if the suspicious area is too large to sample easily with a needle. Prior to the biopsy, the surgeon may use imaging studies to place a small wire into the area of concern. The wire is used as a guide in determining the right tissue for the biopsy.
  • Excisional biopsy. Excisional biopsy is the most involved form of biopsy, using surgery to remove the entire area of suspicious tissue from the breast.

In addition to offering quick results without significant discomfort and scarring, both fine needle aspiration and core needle biopsy give patients the opportunity to discuss treatment options with their doctor before having surgery. In some cases, needle biopsy can be performed right in the doctor's office. However, because needle biopsy takes only a small sample of tissue there is a higher risk of a false negative result, suggesting that cancer is not present when it really is.

Incisional and excisional biopsies are more invasive than needle biopsies. They leave a scar and may require a longer time to recover. As with needle biopsy, there is some possibility that incisional biopsy can return a false negative result. However, the results are available fairly quickly. Excisional biopsy is the surest way to establish a definite diagnosis without getting a false negative result. Having the entire lump removed can also provide some patients with additional some peace of mind.

Breast MRI

Unlike mammography, which uses X-rays to examine breast tissue, magnetic resonance imaging (MRI) scans of the breast use radio waves and strong magnets. During the scan, the energy from the radio waves is absorbed and then released in a pattern formed by the type of body tissue and by certain diseases. A computer translates the pattern into a very detailed image of the breast.

MRI scans present detailed images of the breast and help Penn cancer specialists accurately diagnose and locate breast tumors. Breast MRI has a number of different uses for breast cancer, including:

  • Screening women known to be at higher than average risk for breast cancer, either because of a strong family history or a gene abnormality.
  • Gathering additional information about an area of suspicion found on a mammogram or ultrasound.
  • Screening for women with dense breast tissue.
  • Monitoring for cancer recurrence after treatment.
  • Ruling out other lesions once breast cancer is diagnosed.

Positron Emission Tomography (PET) Scan

PET scans can help cancer specialists at Penn precisely find cancer cells in the body. PET scans create computerized images of chemical changes, such as metabolism, that take place in tissue. This helps locate breast cancer cells as they have a higher metabolism than other tissues in the body.

PET scans are not used to screen for breast cancer, but once breast cancer has been diagnosed, PET scans are used to determine:

  • If the cancer has spread to lymph nodes.
  • If the cancer has spread to other parts of the body and where it has spread.
  • If metastatic breast cancer is responding to treatment.

When appropriate, Penn radiation oncologists use PET for planning radiation therapy. Penn has one of the few radiation oncology departments in the country with a dedicated PET/CT scanner used solely for the purpose of planning radiation treatments The combined matching of a CT scan with PET images improves the ability to discriminate normal from abnormal tissues and helps radiation oncologists check the effectiveness of radiation treatments on the cancer cells.

Staging Breast Cancer

An important part of diagnosing and treating breast cancer at Penn Medicine is staging. Staging is the process of finding out how much cancer there is and where it is located. This information is used to plan cancer treatment and develop a prognosis.

Staging is a way to make sure patients get the best possible treatment. For most cancers, the stage is based on three main factors:

  • Size of the tumor and whether or not it has grown into nearby areas (T)
  • If the cancer has spread to nearby lymph nodes (N)
  • If the cancer has spread to distant areas of the body (M)

Once the TNM are determined, a stage is assigned to the breast cancer:

  • Stage 0. Ductal carcinoma in situ (DCIS), the earliest form of breast cancer is a non-invasive condition. The cancer cells are still within a duct and have not invaded deeper into the surrounding fatty breast tissue. Lobular carcinoma in situ(LCIS) is sometimes also classified as stage 0 breast cancer, but most oncologists believe it is not a true breast cancer. This condition seldom becomes invasive cancer, however, having lobular carcinoma in situ in one breast increases the risk of developing breast cancer in either breast. In LCIS, abnormal cells grow within the lobules or milk-producing glands, but they do not penetrate through the wall of these lobules. Paget disease of the nipple (without an underlying tumor mass) is also stage 0. In all cases, the cancer has not spread to lymph nodes or distant sites.
  • Stage I. The tumor is 2 cm (about 3/4 of an inch) or less across and has not spread to lymph nodes or outside the breast.
  • Stage IIA. One of the following applies and the cancer hasn't spread to distant sites:
    • The tumor is 2 cm or less across (or is not found) and has spread to one to three axillary lymph nodes, with the cancer in the lymph nodes larger than 2 mm across.
    • The tumor is 2 cm or less across (or is not found) and tiny amounts of cancer are found in internal mammary lymph nodes on sentinel lymph node biopsy.
    • The tumor is 2 cm or less across (or is not found) and has spread to one to three lymph nodes under the arm and to internal mammary lymph nodes (found on sentinel lymph node biopsy).
    • The tumor is larger than 2 cm across and less than 5 cm but hasn't spread to the lymph nodes.
  • Stage IIB. One of the following applies and the cancer hasn't spread to distant sites:
    • The tumor is larger than 2 cm and less than 5 cm across. It has spread to one to three axillary lymph nodes and/or tiny amounts of cancer are found in internal mammary lymph nodes on sentinel lymph node biopsy.
    • The tumor is larger than 5 cm across but does not grow into the chest wall or skin and has not spread to lymph nodes.
  • Stage IIIA. One of the following applies and the cancer hasn't spread to distant sites:
    • The tumor is not more than 5 cm across (or cannot be found). It has spread to four to nine axillary lymph nodes, or it has enlarged the internal mammary lymph nodes.
    • The tumor is larger than 5 cm across but does not grow into the chest wall or skin. It has spread to one to nine axillary nodes, or to internal mammary nodes.
  • Stage IIIB. The tumor has grown into the chest wall or skin but hasn't spread to distant sites, and one of the following applies:
    • It has not spread to the lymph nodes.
    • It has spread to one to three axillary lymph nodes and/or tiny amounts of cancer are found in internal mammary lymph nodes on sentinel lymph node biopsy.
    • It has spread to four to nine axillary lymph nodes, or it has enlarged the internal mammary lymph nodes.
    • Inflammatory breast cancer is classified as stage IIIB unless it has spread to distant lymph nodes or organs, in which case it is stage IV.
  • Stage IIIC. The tumor is any size (or can't be found), hasn't spread to distant sites and one of the following applies:
    • Cancer has spread to 10 or more axillary lymph nodes.
    • Cancer has spread to the lymph nodes under the clavicle (collar bone).
    • Cancer has spread to the lymph nodes above the clavicle.
    • Cancer involves axillary lymph nodes and has enlarged the internal mammary lymph nodes.
    • Cancer has spread to four or more axillary lymph nodes, and tiny amounts of cancer are found in internal mammary lymph nodes on sentinel lymph node biopsy.
  • Stage IV. The cancer can be any size and may or may not have spread to nearby lymph nodes. It has spread to distant organs or to lymph nodes far from the breast. The most common sites of spread are the bone, liver, brain or lung.

A Penn cancer physician can answer any questions about the stage of cancer and what it might mean regarding prognosis and treatment.

Breast Cancer Treatment

Breast Cancer Surgery options include breast-conserving surgery such as lumpectomy and partial mastectomy; total mastectomy; modified radical mastectomy; and radical mastectomy.

Two types of breast reconstructive surgery are offered at Penn: natural tissue reconstruction and breast implant reconstruction.

Radiation therapy options include accelerated partial breast irradiation (APBI), which includes breast brachytherapy and external beam partial breast irradiation; 3-D conformal radiation therapy; image-guided radiation therapy (IGRT); intensity-modulated radiation therapy (IMRT); targeted radiation therapy treatment called MammoSite®; internal mammary node irradiation; and prone breast radiotherapy.

Chemotherapy and biologic therapies for breast cancer include chemotherapy, hormone therapy, immunotherapy, and vaccine therapy.

Breast cancer clinical trials are also available at Penn.

Read more Breast Cancer Treatment

Breast Cancer Survivorship

There are more than 12 million cancer survivors living and thriving today as a result of advances in cancer treatment. However, cancer treatments can result in physical, emotional and financial complications long after the therapy is complete. Survivorship programs at Penn Medicine are a distinct phase of breast cancer care and are designed to help patients' transition from their cancer treatment routine to a post-cancer care lifestyle.

Read more Breast Cancer Survivorship


Donna Lee Lista

Donna Lee Lista shares her story.

Clinical Trials

Breast Cancer Trials

Phase III Randomized Trial of the Role of Whole Brain Radiation Therapy in Addition to Radiosurgery... more


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