Mammographic Screening for Breast Cancer

Abstract

A 44-year-old woman who is a new patient has no known current health problems and no family history of breast or ovarian cancer. Eighteen months ago, she had a normal screening mammogram. She recently read that mammograms may not help to prevent death from breast cancer and that "the patient should decide." But she does not think she knows enough. She worries that there is a breast-cancer epidemic. What should her physician advise? THE CLINICAL PROBLEM In 1990, for the first time in 25 years, mortality from breast cancer in the United States began dropping; by 1999, the age-adjusted mortality rate was at its lowest level (27.0 per 100,000 population) since 1973. 1 Meanwhile, by 1997, 71 percent of women in the United States who were 40 years of age or older reported having undergone mammography during the previous two years-an increase from 54 percent in 1989. 2 Ironically, just as screening (or better treatment or both) seemed to be lowering mortality from breast cancer nationally, questions were raised about the validity of the studies that had led to widespread screening. For more than two decades, expert groups uniformly agreed that screening mammography reduces mortality from breast cancer among women in their 50s and 60s, even though they disagreed about other age groups. 3 However, questions were raised in 2000, when two Danish investigators concluded that only three of eight randomized trials were of sufficient quality to determine the effectiveness of mammography and that the combined results of these three trials showed no benefit. This report led to confusion about the usefulness of screening mammography. STRATEGIES, EVIDENCE, AND AREAS OF UNCERTAINTY Women are interested in knowing about breast cancer and want information from their doctors. 4,5 When women and their physicians are making decisions about screening, they need information about the underlying risk of the condition being screened for, the effectiveness of the procedure in preventing an untoward outcome such as death, and the potential ill effects of screening, such as false positive tests. (For policymakers and payers, cost effectiveness is an important factor in decisions about the allocation of finite resources.) Clinical information about each of these issues with regard to breast cancer and mammography is summarized below.

Racial and Geographic Differences in Mammography Screening in St. Louis City: A Multilevel Study

“…We considered women to be adherent to mammography guidelines if they reported having a mammogram in the past 2 years for women age 40-49 and in the past year for women age 50 or older. 17,18,20 Women answering "don't know" or "refused" were set to missing and excluded from the analysis.…”

Gene expression profiling identifies Fibronectin 1 and CXCL9 as candidate biomarkers for breast cancer screening

“…Although mammogram screening has allowed an undisputable benefit, it has several limitations. First, it is associated with a significant rate of false-positive results, leading to unnecessary biopsies or surgeries (Fletcher and Elmore, 2003;Delaloge et al, 2005). Second, this technology mainly detects slowly proliferating tumours that occur after the age of 50 years, but exhibits poor performance to screen aggressive tumours, especially in young women in whom breast density is high.…”

Evaluation of Low-Cost Telemammography Screening Configurations: A Comparison with Film-Screen Readings in Vulnerable Areas

“…To reduce the mortality rates associated with breast cancer, screening programs including routine mammograms have been developed [1][2][3][4][5]. For rural or underserved areas, telemedicine may provide a cost-effective solution for screening mammography programs and computed radiography (CR) and full-field digital mammography (FFDM) are useful in the implementation of telemammography services.…”