Screening with digital mammography: 2-year experiences from Vestfold County, Norway

Abstract

From 1930 to 1990 annual age-adjusted breast cancer death rates for women in the United States remained remarkably constant, oscillating around 32 deaths per 100,000 over 60 years. During this long timeframe, the surgical treatment of breast cancer evolved from radical mastectomy with mandatory lymph node dissection to lumpectomy coupled with radiation therapy. With this new paradigm, lymph node dissection was reserved for women with tumor-invaded axillary lymph nodes. Beginning in the 1970s, chemotherapy after surgery (adjuvant) and before surgery (neoadjuvant) was added to surgical treatment. The radical diminution in the scope of breast surgery did not alter the national breast cancer death rate. Doing less surgery was neither harmful nor beneficial to long-term survival from breast cancer. In the 1980s two events changed this static picture: the addition of tamoxifen to adjuvant and neoadjuvant chemotherapy, and the introduction of mammography. Beginning in 1990 annual breast cancer death rates in the United States began to fall, and have continued to fall each year since then. In 2001, the last year of published statistics, the breast cancer death rate was 26 deaths per 100,000. Best estimates for where to credit this dramatic drop in death rate place approximately 50% of the credit with improved adjuvant chemotherapy and 50% with mammography. Abnormal mammograms demand a breast biopsy since only one in five abnormal mammograms is actually a breast cancer. Consequently, widespread adoption of mammography has produced an image-guided breast biopsy industry in the United States. Open, surgical breast biopsy has been replaced with image-guided breast biopsy because improved breast biopsy tools have made image-guided breast biopsy equivalent in accuracy to open, surgical breast biopsy. These tools, in turn, have changed the professional lives of surgeons, pathologists, and mammographers, leading to the development of dedicated breast surgeons, breast pathologists, and interventional breast radiologists.