The beginning of breast conserving therapy (BCT) coincides with the early days of clinical radiotherapy. Geoffrey Keynes, a London surgeon, practiced breast conserving surgery combined with radiotherapy in the 1920s, and Vera Peters, a Toronto radiation oncologist began using a similar approach in the 1930s.1-4 The results, in terms of overall survival, were comparable to contemporaneous radical surgical results. However, this was likely in large part a result of advanced disease at presentation and the lack of any or adequate systemic therapies, resulting in equivalent rates of death that occurred before progression or recurrence of local disease.
In the 1970s, newer hypotheses emerged regarding the nature of breast cancer, which suggested that patient outcomes (i.e., survival) were dependent on metastatic disease present (or not) at the time of diagnosis. This led to several clinical trials designed to determine whether BCT would provide equivalent outcomes to total mastectomy in women with “early” breast cancer. In Italy, a prospective randomized trial compared modified radical mastectomy to removal of the breast quadrant containing the tumor (“quadrantectomy”) with axillary node dissection plus radiation therapy to the breast.5-7 In the United States, National Surgical Adjuvant Breast and Bowel Project (NSABP) investigators, led by Dr. Bernard Fisher, carried out a trial (B-06) with a more conservative local excision (“lumpectomy”) requiring just a negative margin (“no ink on tumor”), with or without breast irradiation, compared to total mastectomy.8-10 Both trials demonstrated equivalent DFS and OS for BCT and total mastectomy, which persisted for more than 20 years of follow-up. A number of other prospective randomized trials confirmed equivalent outcomes for BCT and total mastectomy.11-14 And in 1990, an NIH consensus statement declared “Breast conservation treatment is an appropriate method of primary therapy for the majority of women with stage I and II breast cancer and is preferable because it provides survival equivalent to total mastectomy and axillary dissection while preserving the breast.”15
“Backsliding” Trends, Possible Reasons
From the 1980s until 2000, especially following release of the 1990 NIH consensus conference statement,15 there was a steady rise in the proportion of women undergoing BCT versus mastectomy in the United States.16-18 However, there were some clear geographic, socioeconomic, and provider differences in this trend, with some parts of the country lagging behind.
In the last two decades, however, several centers have noted reversal of this trend, with more women undergoing unilateral and bilateral mastectomies.19-21 While some have cited increasing use of MRI, the reasons are not entirely clear, and a national survey did not confirm this trend for the United States as a whole.22-25 Some of the factors that may contribute to increased total mastectomy rates include new and better methods of reconstruction, desire for symmetry, freedom from ...