Mammography Reduces More Deaths From Breast Cancer Than Previously Thought (dateline April 25, 2001)
A new study finds that mammography reduces the number of deaths from breast cancer by far more than previously thought. According to the study, regular screening mammograms reduce breast cancer mortality by 63%. Robert Smith, PhD, Director of Cancer Screening for the American Cancer Society and co-author of the study, said that he hopes this new data will convince those women who are skeptical about mammography that the exam can save their lives.
Healthcare professionals should tell women that receiving regular screening mammograms beginning at age 40 can reduce their risk of dying from breast cancer by approximately two-thirds, Dr. Smith told the audience at the American Cancer Societys Science Writers Seminar in April 2001. The reason that mammography saves lives is because the exam detects cancer in its earliest stages, when the chances for successful treatment and survival are the greatest. When breast cancer is detected in advanced stages, the survival rate is low (approximately 16% of advanced breast cancer patients survive past five years).
Previous studies have found that mammograms reduce the breast cancer death rate by approximately 30%. However, many of these studies were conducted in the 1970s and 1980s when many women did not receive annual screening mammograms. The studies also did not take into account that some of the women refused to get mammograms or that cancer was detected in other women before they were offered screening mammograms.
This most recent study on mammography was conducted in two counties of Sweden that had historically high rates of cancer screening (Dalarna and Ostegotland). In the study, women between the ages of 40 and 69 received an invitation for a free mammogram every two years. Those who did not respond received additional notices to further remind them. According to Dr. Smith, those women who received regular screening mammography reduced their risk of dying from breast cancer by 63% when compared to data from the 1970s, when women did not typically receive screening mammograms. While part of the decline in deaths is due to advances in breast cancer treatments, Dr. Smith said that mammography is responsible for most of the reduction in breast cancer mortality since there was no significant trend of increased survival among women who refused to have annual screening mammograms in the study.
Unfortunately, the invitation system for mammograms in not possible in the United States because the healthcare system is not centralized, said Dr. Smith. However, many large HMOs have begun to send their eligible customers reminders to get annual mammograms. Most insurance providers will cover the cost of mammography for eligible women, although women should check with their insurance providers prior to scheduling the exam to be sure.
This latest study showing that mammograms drastically reduce breast cancer mortality comes shortly after the United States Institute of Medicine released its report which found mammography to still be the "gold standard" in breast cancer detection. Mammography detects approximately 85% of all breast cancers and can detect cancer years before a lump can be felt. However, because mammography misses approximately 15% of cancers, women should also practice monthly breast self-exams and receive regular physician-performed clinical breast exams.
Guidelines for early breast cancer detection: