History of the Procedure: Over the greater part of the last century, all forms of breast cancer have been treated by aggressive surgical resection. In 1894, Halsted described the procedure of en bloc removal of all breast tissue, draining lymph nodes and pectoralis muscles for the treatment of breast cancer. This technique of radical mastectomy became the standard of care for decades based on an understanding that cancer growth proceeded in stepwise fashion via the lymphatics, thus could be controlled with surgical excision.
In 1971, Fisher et al challenged this standard and demonstrated in the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-04 trial that radical mastectomy had no survival benefit over mastectomy with radiation or mastectomy with delayed axillary dissection. In a subsequent study, NSABP B-06, patients were randomized to total mastectomy versus lumpectomy and radiation therapy (XRT), and no survival benefit of total mastectomy was found. However, benefit was observed in the decreased rate of local recurrence in women receiving XRT. Development of new chemotherapeutic and hormonal agents has further revolutionized the management of breast cancer.
For excellent patient education resources, visit eMedicine's Cancer and Tumors Center, Women's Health Center, and Imaging Center. Also, see eMedicine's patient education articles Breast Cancer, Mastectomy, Breast Lumps and Pain, Breast Self-Exam, and Mammogram.
Problem: Worldwide, the overall incidence of breast cancer varies markedly but appears to be rising. Far eastern countries such as Japan, which historically have enjoyed low rates in comparison to the United States, are seeing a rapid rise in incidence. Although the United States has the highest reported incidence of breast cancer in the world, several western European nations such as Iceland, Italy, France, Sweden, and the United Kingdom trail closely behind. Incidence has been historically lower in Eastern Europe, the Middle East, and the Far East, but countries such as Japan and Singapore have seen a 2-fold rise over the past few decades.
Frequency: Of American women, 13% will be diagnosed with breast cancer in their lifetimes, making it the most common nonskin cancer among women. In addition, more than 3% will die from the disease. Breast cancer has surpassed lung cancer as the leading cause of cancer death in women worldwide, accounting for more than 400,000 deaths per year. In the United States, breast cancer trails only lung cancer as the second most common cause of cancer death in women. In 2002, more than 1.15 million new cases were diagnosed worldwide. More than 200,000 of these were in the United States alone.
The 1980s saw the greatest rise in incidence, which may have been due to a combination of improvements in screening techniques, data collection, and treatment modalities. Despite this surge in newly-diagnosed cases, mortality rates have been declining over the last decade. The decline is widely attributed to earlier detection via screening mammography and improvements in hormonal therapy and chemotherapy.
Etiology: Risk factors for the development of invasive breast cancer include female gender, age, family history, age at the time of first parturition, personal history of previous breast cancer, hormone replacement therapy, history of atypical hyperplasia or noninvasive lesions, and genetics.
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