Health

Know Your Own Risks of Breast Cancer

January 31, 2002 / 8:40 AM EST / CBS

Dr. Emily Senay talks to us about how a woman can calculate her own risk factors of breast cancer, the pre-existing risk factors and how she can lower her risk factors.

Approximately 180,000 new cases of breast cancer are diagnosed annually, accounting for about 48,000 deaths per year in the United States. Increased awareness of the signs and symptoms of breast cancer and the use of screening mammograms mean that breast cancer is being diagnosed at earlier stages.

Current screening guidelines recommend women older than the age of 40 have annual mammograms and clinical breast examinations. Women older than 20 years should be encouraged to do monthly breast self-examinations. For women between the ages 20 and 39 years, a clinical breast examination every three years is recommended.

These guidelines are modified for women with risk factors, particularly those with a strong family history of breast cancer. Ultrasonographic studies are most useful to evaluate cystic breast masses. For solid masses, diagnostic biopsy techniques include fine-needle aspiration, core biopsy and excisional biopsy.

Breast cancer is the second most commonly diagnosed cancer among women, after skin cancer. Approximately 182,800 new cases of invasive breast cancer will be diagnosed among women in the US during 2000-2001. After increasing about four percent per year during the 1980s, breast cancer rates leveled off in the 1990s to about 110 cases per 100,000 per year. Breast cancer is the second leading cause of cancer death in women, after lung cancer. Approximately 48,800 American women are expected to die of breast cancer in 2000-2001.

Demographics

The incidence of breast cancer increases with age. White women are more likely to develop breast cancer than black women. The incidence of breast cancer in white women in 1993 was about 113 cases per 100,000 women and in black women, 100 cases per 100,000. However, black women younger than 50 years have a higher incidence of breast cancer than white women of the same age. In 1993, data showed that black women were more likely to die of breast cancer than white women. Although breast cancer usually is associated with women, one percent of breast cancer occurs in men. Men should be aware of the relevant risk factors, including family history, and be encouraged to report any changes in their breasts to a physician.

Risk Factors

Several well-established risk factors are associated with the development of breast cancer, primarily age and female sex. Family history is highly significant in a first-degree relative (i.e., mother, sister, or daughter) especially if the cancer has been diagnosed premenopausally. Women who have premenopausal first-degree relative with breast cancer have a three to four fold increased risk of developing breast cancer than women who do not.

Having several second-degree relatives with breast cancer may further increase the risk of developing breast cancer, but this risk has not been quantified. It is important to note that most women with breast cancer have no identifiable risk factors.

Approximately eight percent of all cases of breast cancer are hereditary. About one half of these cases are attributed to mutations in two breast cancer susceptibility genes, BRCA1 and BRCA2. Hereditary breast cancer commonly occurs in premenopausal women and is more frequently bilateral than nonhereditary breast cancer. Several family members are affected over three generations or more and can include women from the paternal side of the family. Screening tests are available to detect BRCA mutations.

Obtaining a history of previous breast biopsy is essential because a history of a proliferative abnormality such as atypcal hyperplasia on biopsy may increase a woman's risk for developing breast cancer. A history of breast cancer increases the risk of developing a new breast cancer by 0.5 to 1.0 percent per year. Because conservative treatments are increasingly common in women with first breast cancers, many second cancers now appear in the same breast.

Early menarche and late menopause may also increase the risk of breast cancer by affecting lifetime exposure to hormones. Women who give birth to their first child after age 30 or who never become pregnant are also at an increased risk. Apparently, an increase in female reproductive hormones accelerates cell division in breast tissue, which in turn augments the risk of mutations. Use of oral contraceptives may minimally increase the risk of breast cancer, but women who have used oral contraceptives for less than 10 years have the same risk as women who have never used them. Many studies have looked at the risk of estrogen replacement therapy (ERT). While there may be a slight increased risk with ERT, this risk is usually offset by the benefits. High social economic status, white race and exposure to ionizing radiation are other risk factors for developing breast cancer.

International variations in breast cancer rates appear to correlate with variations in diet, especially fat intake. However, relevant dietary factors have not been firmly established. Other factors that may be associated with increased risk of breast cancer currently being studied include chemical exposure, alcohol consumption, weight gain, induced abortion and physical inactivity. Although women cannot change some of their inherited and personal risk factors, they can alter their diet to one that is low in fat and high in fiber, and reduce alcohol consumption. A recent study shows that Tamoxifen, the selective estrogen receptor modulator, reduces the risk of developing breast cancer. Raloxifene, a similar compound, may also reduce the risk.

Signs and Symptoms

Detection of a breast mass is the most common breast complaint for which women seek medical advice, and nearly 90% of all such breast masses are results of benign lesions. Smooth and rubbery masses are usually associated with fibroadenoma in women in their 20s and 30s or cysts in women in their 30s and 40s.

Breast pain is also a common presenting problem. Mastalgia is rarely associated with breast cancer and is usually related to fibrocystic changes in premenopausal women. Postmenopausal women receiving estrogen replacement therapy may also present with breast pain caused by fibrocystic changes. The pain of fibrocystic conditions is associated with diffuse lumpy breasts.

Erythema, edema and retraction of the skin or nipple are associated with malignancies. Another common presenting problem is nipple discharge. Discharge from a breast carcinoma is usually spontaneous, bloody, associated with a mass and localized to a single duct in one breast.

Breast Exams

Examination of the breast should be performed in the upright (sitting) and supine positions with the woman's hands behind her head. The breasts should be inspected for differences in size, retraction of the skin or nipple, prominent inenous patterns and signs of inflammation. The flat surface of the fingertips should be used to palpate the breast tissue against the chest wall. The axillary (armpit) and supraclavicular areas should be checked for adenopathy. The nipple should be gently squeezed to check for discharge.

A mass that is suspicious for breast cancer is usually solitary, discrete and hard. In some instances, it is fixed to the skin or the muscle. A suspicious mass is usually unilateral and nontender. Sometimes, an area of thickeninthat is not a discrete mass may represent cancer. Breast cancer is rarely bilateral when first diagnosed.

A careful history of a woman's risk and symptoms and a thorough physical examination are important in the evaluation of breast problems. Appropriately timed imaging and diagnostic studies are also important. Early detection of breast cancer at a stage when it is potentially curable and there is the possibility of saving a breast should be the goal of all health care professionals.