Breast cancer is the most common non-skin cancer among women in the United States. It is the second leading cause of cancer death in women. Approximately 200,000 new invasive breast cancers will be diagnosed this year. The chance of a woman developing breast cancer some time during her life is approximately one in eight.
Breast cancer can present as either non-invasive (in situ) or invasive forms. Another name for non-invasive breast cancer is ductal carcinoma in situ (DCIS). DCIS is confined to the milk ducts. While it is a type of cancer, it rarely spreads to other parts of the body. Treatment for this type of cancer is almost always successful. Lobular Carcinoma in Situ (LCIS) refers to a condition which is a marker of increased risk for developing breast cancer but itself is not considered malignant.
Invasive breast cancer refers to cancer that has already invaded or spread beyond the milk ducts or breast lobules of the breast and therefore has the potential to spread to lymph nodes or other parts of the body. Invasive breast cancer typically comes in one of two forms: invasive ductal cancer and invasive lobular cancer. The more common type of invasive breast cancer is the ductal type. Both of these are typically treated by surgery, possibly in combination with radiation therapy, chemotherapy, and/or hormone therapy.
Other types of breast cancer such as inflammatory breast cancer require special considerations in planning treatment. In addition, conditions that increase the risk of developing invasive breast cancer such as LCIS should be managed by those who have expertise in advising risk reduction strategies.
Men can also develop breast cancer, though this is quite rare and occurs approximately 1% as often as in women. Approximately 2,000 new cases of invasive male breast cancer will be diagnosed each year in the United States. Overall, the lifetime risk of developing breast cancer for a man is approximately 1 in 1,000.
Symptoms of Breast Cancer
Symptoms or signs which may indicate there is an underlying cancer include:
- New breast mass
- Swelling in part or all of the breast
- Skin dimpling
- Nipple discharge that may be clear or bloody
- Bleeding/crusting of the nipple
- Localized breast pain
- Skin changes of the breast including thickening, scaling, redness or ulceration
- Swollen lymph nodes under the arm
Even for women without symptoms, it is recommended that all women have mammograms on a regular basis since breast cancer is often detected by mammography before any symptoms develop. Screening guidelines are the subject of much discussion currently and vary among organizations however annual mammographic screening for women over the age of 40 has been advised by some for women of average risk. Screening for women at increased risk of breast cancer should be discussed with a physician as it often starts at an earlier age and may include the use of MRI.
Risk Factors for Breast Cancer
Breast cancer, like many other cancers, increases in frequency with age. A majority, approximately 85% of cases, occur in women age 50 or older.
Other risk factors are listed below:
- Personal history of breast cancer. Individuals who have experienced breast cancer once are at increased risk of developing a second breast cancer. The risk of developing a second breast cancer is about ½% to 1% per year for patients who have had breast cancer once.
- Individuals with a family history of breast or ovarian cancer are at a higher risk of developing breast cancer themselves. Women with an especially strong history (i.e. two or more first degree relatives with breast or ovarian cancer) may have a greater than 50% chance of developing breast cancer and are commonly referred for genetic consultation and testing.
- There are heritable risk factors that may involve a genetic mutation in genes such as BRCA1 or BRCA2 or other genes such as p53 or PTEN. Genetic testing is available for BRCA and other mutations and may be obtained, if warranted, after careful discussion with your physician.
Other risk factors are as follows:
- Women who have taken hormone replacement therapy, especially those women taking a combination of an estrogen and progestagen for more than 2-3 years.
- Women who have had radiation to the chest, particularly during teenage years and early adulthood are at increased risk of developing breast cancer.
- Women with a history of increased breast density on mammography appear to be at an increased risk of developing breast cancer.
- Women who have undergone breast biopsy, primarily those women with a finding of atypical hyperplasia on a biopsy may have an increased risk of developing breast cancer. Common breast conditions such as fibrocystic change or fibroadenoma do not appear to increase a woman’s risk of developing breast cancer.
- Prolonged estrogen exposure - such as earlier age at onset of menses or later age at onset of menopause - both result in longer lifetime exposure to estrogen and may increase a woman’s risk of developing breast cancer.
- Similarly, women who have never given birth and women who have their first child after the age of 30 have an increased risk of breast cancer as compared to women with multiple births or women who give birth before the age of 30. Breast-feeding may reduce a woman’s risk of breast cancer.
- The use of hormone replacement therapy, specifically the combination of estrogen and progestin, for five or more years, has been associated with an increased risk of breast cancer in women.
- Alcohol consumption has been associated with an increased risk of breast cancer. The consumption of certain alcoholic beverages has been associated with some protective effects in other diseases and thus, the overall risk and benefits of consuming alcohol containing beverages should be discussed with a physician.
- There are other factors that have been associated with the risk of developing breast cancer although the reasons remain unclear. Women of higher socioeconomic status may be more likely to develop breast cancer. In addition, smoking appears to increase a woman’s lifetime risk of breast cancer.
How Breast Cancer is diagnosed
A suspicious breast abnormality is often first identified by mammography. An ultrasound or a magnetic resonance image (MRI) may be obtained to further characterize the abnormality.
In order to make the diagnosis, a piece of tissue must be obtained – called a breast biopsy. This is often done by the surgeon in the office, using either a fine needle or core needle and with local anesthesia. Increasingly, more and more breast biopsies are done by the radiologist following an abnormal mammogram or ultrasound. A suspicious breast mass or cluster of calcifications is seen by the radiologist, and either a stereotactic core biopsy (for an abnormal mammogram) or an ultrasound-guided core biopsy (for an abnormal ultrasound) is recommended.
Occasionally, patients may still need an open surgical biopsy to establish the diagnosis of cancer. Once the biopsy is completed, the tissue is then sent to the pathology lab to be examined under the microscope. The tissue is evaluated to determine if it is malignant, and special stains may be ordered to determine the exact type and options for treatment.
The role of breast self examination is detecting early stage breast cancer is controversial and its value should be discussed with a physician. One should not rely on breast self examination alone to screen for breast cancer.
Treatment Options for Breast Cancer at Tufts Medical Center
The treatment for breast cancer is individualized for each woman and is primarily based upon stage and the age of the patient. The stages range from Stage 0 (non invasive) to Stage IV with the lower numbers corresponding to less advanced disease. Options for treatment include surgery, radiation, and chemotherapy and hormone therapy. These options can be combined in a variety of ways to best treat each individual. For patients with hormone sensitive breast cancer, hormone therapy, such as tamoxifen and aromatase inhibitors, may frequently be used for prolonged periods of time to help reduce the risk of cancer from coming back.