From radical mastectomy to breast-conserving surgery (BCS), the last 35 years have witnessed a fascinating evolution in the role of surgery in the treatment of breast cancer. For almost a century, Halsted's mastectomy was the treatment of choice for all stages of breast cancer. However, multiple prospective, randomized trials with more than 20 years' follow-up have since documented that breast-conserving operations followed by whole-breast irradiation offers survival outcomes equivalent to mastectomy in appropriately selected patients.
Breast-conserving surgery is defined as the complete removal of the tumor with a concentric margin of surrounding healthy tissue with maintenance of acceptable cosmesis, and should be followed by radiation therapy to achieve an acceptably low rate of local recurrence. Appropriate selection of patients, adequate surgery, and breast irradiation are important components of successful breast-conserving therapy (BCT). Surgical evaluation of the axillary lymph nodes should be performed in patients undergoing BCT for invasive carcinoma, but the status of the axilla does not influence the decision on BCS. Incorporating oncoplastic techniques may be considered to optimize cosmetic outcome in select patients.
Six modern, prospective, randomized trials have demonstrated that breast-conserving therapy (lumpectomy followed by radiation) offers survival rates equivalent to mastectomy (Table 61-1)1-7; however, when negative margins are not achieved or when radiation therapy is not pursued, breast conservation is associated with higher rates of local recurrence (Tables 61-1 and 61-2).1,2,8-14 Until recently, the impact of local recurrence on survival remained unclear. In 2005, the Early Breast Cancer Trialists' Collaborative Group (EBCTCG) published the results of a large meta-analysis combining all individual patient data for 42,080 women who collectively took part in 78 treatment comparisons (more vs less surgery, more surgery vs radiotherapy, radiotherapy vs none) to determine the impact of local recurrence on survival. Specifically, among 10 breast-conservation trials included in the EBCTCG analysis (7311 women), postoperative radiation treatment (XRT) was associated with a statistically significant reduction in local recurrence in each individual trial. Furthermore, postoperative XRT was associated with an overall absolute reduction in local recurrence of 19% at 5 years, an absolute reduction in breast cancer–specific mortality of 5.4% at 15 years, and similar reductions in 15-year overall mortality. They concluded that optimal locoregional control does confer a quantifiable survival benefit in early-stage breast cancer and as such the importance of local control is no longer a matter of debate.15
Table 61-1 Prospective, Randomized Trials Comparing Mastectomy and Axillary Dissection to Breast-Conservation Therapy ||Download (.pdf)
Table 61-1 Prospective, Randomized Trials Comparing Mastectomy and Axillary Dissection to Breast-Conservation Therapy
|Clinical Trial||Dates||N||TNM||Margin Status||XRT Boost||Follow-Up (Years)||LOCAL RECURRENCE (%)||OVERALL SURVIVAL (%)|
|NSABP B061||1976-1984||1217||≤4 cm N0N1 M0||Tumor free||Yes||20||10.2||14.3||47.2||46.2|
|EORTC5||1980-1986||874||≤5 cm N0N1 M0||1 cm||Yes||8||10||15||64||66...|