The most common form of malignancy in women in the United States is breast cancer with a mortality second only to lung cancer. The American Cancer Society estimated that 182,800 new cases would be diagnosed in the U.S. during the year 2000 and 40,800 deaths would occur. The incidence for breast cancer is highest among Caucasians but African-American women have a higher mortality rate and are more likely to be diagnosed at a more advanced stage of disease, lessening their five-year survival rate by 15%.

The incidence of breast cancer increases with advanced age

Though women over the age of 65 constitute only 13% of the U.S. population, they reflect 48% of newly diagnosed cases of breast cancer and approximately 40% of invasive breast cancer cases. For women over the age of 65, estimated breast cancer incidence is 444.6 per 100,000 women; for women under the age of 65, the incidence rate is 72.9 per 100,000 women. The combination of an increasingly older population and a cancer with a high incidence in this age group points to breast cancer as a significant health care issue.

Screening for breast cancer is an effective means of early detection

The primary screening methods are self-examination, mammography and clinical exam by a trained health care professional. In one study, the ability to detect breast cancer by self-examination had an estimated sensitivity of 26% compared with 75% when combined with mammography. The average sensitivity of mammography is approximately 90% and the specificity is 94%. Randomized trials have shown a 26% reduction in mortality as a result of breast cancer screening in the 50 to 74 age group.

Controversy in recent years has occurred concerning at what age mammography should begin and how often

Most agree that annual screening mammograms for all women should begin at age 40. There is, however, no consensus about when to stop screening. One study reported that, in terms of lives saved per screening, there was a greater decrease in mortality in women aged 65-74 compared to women aged 50-64 years. There does seem to be an important benefit from mammograms in the elderly despite rising co-morbid conditions that could contribute to death.

Breast cancers are often detected by the patient during a routine, self-exam as a painless, hard mass or an area of irregular skin thickening. The most common site of origin for breast cancer is the upper outer quadrant (38.5%), followed by the central area (29%), the upper inner quadrant (14.2%), the lower outer quadrant (8.8%) and the lower inner quadrant (5%); this distribution corresponds to the amount of breast tissue in the various quadrants.

Approximately five years of growth would be needed for a tumor in the breast to reach a size to be noted on physical exam. Other signs may be breast pain, dimple in the skin, nipple discharge, skin retraction or erosions. Abnormalities on mammograms most suggestive of cancerous lesions are those that are spiculated and have ill-defined margins. Spiculations are radiations of cancer cells and fibrous tissue stands that appear to develop in response to tumor.

A suspicious lesion requires further evaluation

Biopsy techniques for palpable breast lesions include fine-needle aspiration (FNA), core biopsy and excisional biopsy. FNA is quick, painless and inexpensive but produces many false negatives (4% to 9.6%) and is also unable to distinguish reliably invasive cancer from ductal carcinoma in situ (DCIS).

Core biopsy is also rapid and pain-free but provides better histologic detail than FNA; however, it can fail to provide a complete evaluation of the entire lesion. Excisional biopsy is the standard technique for the diagnosis of breast masses, allowing better characterization of the tumor size, histology and an opportunity to remove a margin of normal tissue around the mass, an important factor in staging and subsequent choice of therapy.

Local treatment of breast cancer has evolved over many years and is now a collaborative effort among surgeons, medical and radiation oncologists and pathologists

Previously, the surgery of choice was radical mastectomy in which the skin, pectoral muscles, axillary lymph nodes and subcutaneous fat were removed. With the earlier detection of breast cancer, fewer large, fixed tumors were being detected and patients underwent a modified radical mastectomy (pectoral muscles spared). To further spare tissue, lumpectomy, in which the tumor and an area of normal tissue were removed, was considered. A major study compared modified radical mastectomy vs. lumpectomy alone vs. lumpectomy with external beam radiation to the breast. The results showed no significant difference in overall survival but did demonstrate less tumor recurrence in the involved breast for the lumpectomy + radiation group.

Incorrect assumptions about older women and their ability to withstand standard therapy may lead some physicians to treat these patients less aggressively. Epidemiological studies show that women at the age of 70 can expect to live another 15 years and at the age of 80 can expect to live another seven years, thus women inadequately treated for breast cancer may live long enough for cancer to recur locally. Moreover, data analysis shows that older women have a favorable surgical risk.

Axillary node dissection, as a means of further defining the extent of breast cancer involvement, is often not performed in elderly women. Studies appear to indicate that axillary lymph node dissection in the elderly can be omitted. However, newer techniques, using the sentinel axillary lymph node as a means of predicting lymph node positivity, will require additional trials to determine its role in older women with breast cancer.

The use of tamoxifen, an anti-estrogen, as adjuvant therapy in breast cancer in elderly women has been demonstrated to be effective

Tamoxifen for primary prevention of breast cancer among women age 60 or older produced a nearly 50% decrease in invasive breast cancer. Elderly women tolerate tamoxifen well, with over two-thirds of patients reporting minimal or no adverse effects. The duration of therapy with tamoxifen seems to favor two to five years of use over less than two years because of higher overall and recurrence-free survival.

The use of chemotherapy in the elderly is more controversial

Chemotherapy for this age group has not demonstrated a survival benefit and, moreover, there is concern about increased toxicities, especially with respect to co-morbid conditions. Until additional data emerges, the use of chemotherapy as an adjuvant should be employed with caution.

Summary

Older women make up one of the fastest growing segments of the population. Breast cancer, rising in incidence overall, is a significant health care issue in the geriatric community. The use of patient education, self-examination and mammography can be helpful to detect breast cancer at an early stage.

Elderly women should be offered modified radical mastectomy or breast conserving therapy consisting of limited surgery, followed by radiation and adjuvant tamoxifen, based on their clinical presentation and staging. Adjuvant tamoxifen should be considered for all high-risk node-negative and all node-positive women. The benefits of chemotherapy as an adjuvant have not been shown to outweigh the risks for elderly women.