Breast Conservation Therapy with or without Radiation Therapy vival benefit of 10% at 10 years among women with stage II to III breast cancer, regardless of menopausal status (49–51). Additional trials challenged the need for postmastectomy radiation among women with only one to three involved axillary nodes and T1 or T2 primary tumors. These studies showed adequate local–regional control rates with mastectomy and chemotherapy alone (52–54). In a large meta-analysis, an absolute risk reduction in local recurrence was found in women with radiation therapy after both breast conservation and mastectomy. One breast cancer death is avoided for every four local recurrences, reducing the 15-year mortality among patients with a greater than 10% risk of local recurrence (55). Guidelines from the American Society of Clinical Oncology recommend postmastectomy radiation therapy for women with T3 (>5 cm) primary tumors and four or more positive axillary lymph nodes (56).
Radiation therapy alone, without excision of the tumor, is associated with a high local failure rate, as is local excision without radiation (57–60). Throughout the last quarter of the 20th century, a paradigm shift occurred in the surgical management of breast cancer. Data from the NSABP B-04 trial, for which 25-year follow-up exists, established the equivalency of radical versus total mastectomy with regard to overall survival. Shortly after initiation of the B-04 trial, a number of studies were designed to evaluate the efficacy of breast preservation among women with early-stage breast cancers. The Milan trial, a major prospective randomized trial that began accruing patients in 1973, compared treatment with either radical mastectomy or a combination of quadrantectomy, axillary lymph node dissection, and postoperative radiation therapy. In total, 701 clinically node-negative patients with noncentrally located, small tumors (<2 cm) (T1 N0 M0) were enrolled. After 25 years of follow-up, there continues to be no statistically significant difference between the two groups in either local control or overall survival rates (61).
At nearly the same time, in the NSABP B-06 trial, patients with early breast cancer (stage I or stage II, T1 or T2, and N0 or N1) were randomized to modified radical mastectomy, segmental mastectomy (lumpectomy) and axillary lymph node dissection, or segmental mastectomy, axillary lymph node dissection and postoperative radiation therapy. Unlike the quadrantectomy performed in the Milan study, segmental mastectomy consists of removing only the tumor and a small rim of normal surrounding tissue, yielding cosmetically superior results (Fig. 40.3). A total of 1,843 women were enrolled, with the lowest local recurrence rate
Figure 40.3 Appearance of breast after lumpectomy, axillary dissection, and radiation therapy. (From Kruper L, Giuliano AE. Breast disease. In: Berek JS, Hacker NF. Berek & Hacker’s Gynecologic Oncology. 5th ed. Philadelphia, PA: Williams & Wilkins, 2010:638.) seen among patients treated with segmental mastectomy and postoperative radiation therapy. The addition of radiation improved the local control rate, but no significant differences in overall survival or disease-free survival rates were detected among the three treatment arms; there was a trend, however, in favor of patients who had received radiation. This NSABP study established, now with 25-year follow-up, that the combination of segmental mastectomy (with negative surgical margins), axillary lymph node dissection, and postoperative radiation therapy is as effective as modified radical mastectomy for the management of patients with stages I and II breast cancer (62). A number of additional prospective randomized studies also demonstrated no decrease in overall survival among women being treated with breast preservation therapy (63–65).