An Overview of Breast Cancer

Witten by: Alan C. Rothrock, M.D.

Breast cancer is the most common female cancer in the United States, the second most common cause of cancer death in women (after lung cancer), and the main cause of death in women ages 45 to 55.  Every year, approximately 205,000 American women are diagnosed with breast cancer and more than 40,000 die from this disease.

The death rate from breast cancer has declined about 20 percent over the past decade.  This is due in part to increased screening for breast cancer, which can detect the disease at an earlier stage when the chances of successful treatment are higher.  Early detection and treatment of breast cancer clearly improve survival because the breast tumor can be removed before it has a chance to spread.

How do we screen for breast cancer?  A variety of imaging modalities have been developed for identifying lesions that are suspicious for breast cancer.  Mammography remains the mainstay of screening for breast cancer.  Ultrasound is commonly used for follow-up of an abnormality seen on mammogram (mainly to clarify features of a suspicious lesion).  Often, more detailed mammograms are performed for the same reason.  Magnetic resonance imaging (MRI) has shown promise in detecting breast cancer.  However, it is currently reserved for evaluation of high-risk patients.

If cancer is suspected on a screening test, the next step is to confirm the diagnosis.  This is accomplished by removing a small piece of tissue from the abnormal area (known as a biopsy).  The biopsy technique is variable.  However, it generally includes inserting a needle into the suspicious area to remove a small amount of tissue.  Depending on the size of the lesion, ultrasound and MRI may be needed to help localize the area (especially for small lesions).

What happens after a diagnosis of breast cancer? For all cancers, including breast cancer, the specific treatment and prognosis depend upon multiple factors.  The “stage” of breast cancer is a way to determine its severity.  Factors that determine stage include the size of the tumor in the breast, whether there is involvement of the skin, chest wall, or lymph nodes, and whether there is evidence that the cancer has spread to other organs.  The higher the stage, the more advanced the disease.

Women with early disease (early stage) have two surgical options:  mastectomy (removal of the breast) and breast conserving therapy (removal of the cancerous tissue, called a lumpectomy).  Most women with the earliest stage of disease are acceptable candidates for breast conserving surgery, while the rest undergo mastectomy.  Breast conserving therapy is usually recommended in conjunction with radiation therapy to the remainder of the affected breast.  This combination of surgery and radiation usually results in cosmetically acceptable preservation of the breast without compromising breast cancer survival.

Women with more advanced breast cancer may need adjuvant systemic therapy (body-wide anti-cancer treatment).   The goal of adjuvant therapy is to eliminate any tumor cells that might remain in the body after surgery.  It can significantly decrease the chance that a cancer will return, and it improves the chances of surviving breast cancer. 

There are several different modalities for adjuvant therapy.  This includes 1) endocrine therapy 2) traditional chemotherapy or 3) molecularly targeted therapy against specific proteins.  Endocrine therapy is targeted towards hormone receptors found in some breast cancers.  Tumors are tested for estrogen and progesterone receptors and if found, patients may benefit from medications like tamoxifen.   A protein called HER2 is present in about 20 percent of breast cancers.  There is a new medication available directed against this protein that can help enhance survival called Trastuzuma.

Very advanced disease (late stage) rarely permits long-term survival without the disease returning.  However, treatments can prolong life, delay the progression of the cancer, relieve cancer-related symptoms, and improve quality of life.

The research surrounding breast cancer is ever advancing and evolving.  New methods of early detection as well as treatment are currently being studied.  Determining the optimal treatment of breast cancer is complex and must be individualized.  Proper treatment in most cases requires collaboration between surgeons (typically cancer surgeons and reconstructive plastic surgeons), and physicians who specialize in radiation and medical oncology.  Every woman who faces this disease should discuss all options with her team of doctors, so that the best possible treatment can be determined for her.