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Breast Cancer Medicine: Present and Future Dr. Larry Norton
Deputy Physician-in-Chief
for Breast Cancer Programs |
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If cancer is found, several other tests may be performed to fully characterize its stage and type. This information is vital for choosing the best treatment plan for each individual patient.
Not all breast cancers are the same, and patients may present with different stages of the disease. There are several pathologic types of breast cancer, and sometimes more than one type is seen in the same patient. Evaluation of a tumor's microscopic characteristics is also very important to help determine how likely it is that the cancer will spread to other parts of the body and what type of therapy is most appropriate in each case.
After a woman learns that she has breast cancer, she may take at least a few days -- and perhaps a few weeks -- to learn about her treatment options and to think about which treatment is best for her, both medically and personally. Breast cancer is often treated with a combination of surgery, chemotherapy, radiation therapy, and/or hormonal therapy based on characteristics of the cancer and disease stage.
Types of Breast Cancer
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Lobular carcinoma in situ (LCIS)
Lobular carcinoma in situ (LCIS) is made up of abnormal cells located within the lobules. This is not a cancer, but rather a marker of an increased risk of developing breast cancer in either breast.
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Ductal carcinoma in situ (DCIS)
Ductal carcinoma in situ (DCIS) is preinvasive breast cancer in which all of the cancer cells are contained in the milk ducts. Treatment may consist of surgery and radiation. DCIS can progress over time and break out of the milk ducts to become invasive (infiltrating) breast cancer.
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Invasive or Infiltrating Cancer:
The majority of breast cancers are of the ductal type. Some are lobular. Occasionally the cancer consists of less frequently seen tubular, papillary, medullary, or mucinous types.
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Inflammatory Breast Cancer
Breast cancers rarely present with inflammatory changes in the breast which can mimic other conditions such as a skin infection. The skin may appear red or discolored, or may take on a "peau d'orange" appearance (skin thickening with tiny dimples like an orange peel). Women who observe these breast changes should see a healthcare provider immediately.
Features of Breast Cancer
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Stage
The stage of a cancer, sometimes referred to as TNM, is used to determine the type of treatment a woman should receive. It is calculated based on several factors:
- Size of the tumor (T)
- Whether or not the cancer has spread to the axillary (underarm) lymph nodes, and if so, to how many (N)
- Whether or not the cancer has spread to other lymph nodes of the neck or chest area
- Whether or not the cancer has spread (metastasized) to other parts of the body (M)
Tests that may be used to determine how far a breast cancer has spread include a chest x-ray and blood tests. Depending on the clinical presentation, a physician might also order a bone scan, a CT scan, a PET scan, or MRI scan to assess the extent of the disease.
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Hormone Receptor Status
Breast cancer cells that have receptors for the hormones estrogen and/or progesterone are called estrogen receptor (ER) and/or progesterone receptor (PR) positive. If these receptors are not present, the cell is said to be receptor-negative.
Tumors that are receptor-positive are more likely to respond to therapy with anti-estrogen medications, which take advantage of the cancer cell's dependence on hormones for growth. The drug tamoxifen, for example, acts by blocking the estrogen receptors of a breast cancer.
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HER2/neu Status
HER-2/neu is a gene that, when activated, helps tumors grow by producing a specific growth-stimulating receptor. Tumors that have more than normal amounts of this protein (HER2-positive) may benefit from the drug trastuzumab (Herceptin®), which blocks the growth of tumors activated by the gene, or a similar drug called lapatinib (Tykerb®).
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Grade
Grade is an evaluation of how abnormal or disorganized the cells appear when examined under a microscope. In general, a lower grade implies a less aggressive tumor.
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Lymphovascular or perineural invasion
Sometimes tumor cells can invade the blood vessels, or the lymph or nerve channels within breast tissue.
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Gene Expression Profiling
Oncotype DX® is a test that is used to analyze the expression pattern of 21 gene in patients with a breast tumor that is estrogen-receptor-positive and axillary-lymph-node-negative. The pattern is translated into a recurrence "score" that attempts to predict which women will benefit most from treatment with chemotherapy in addition to hormonal therapy, and which women might be safely spared chemotherapy. This test is part of a novel and increasingly popular approach called "personalized medicine" for cancer, in which the molecular features of the specific tumor are analyzed to determine optimal treatment for each individual.
