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Local Recurrence of Breast Cancer After MammoSite® Brachytherapy
References 1. Silverstein M, Lagios M, Craig P, et al: A prognostic index for ductal carcinoma in situ. Cancer 77:2267-2274, 1996. 2. Jeruss JS, Vicini F, Beitsch PD, et al: Initial outcomes for patients treated on the American Society of Breast Surgeons MammoSite clinical trial for ductal carcinoma-in-situ of the breast. Ann Surg Oncol 13:967-976, 2006.
Local Recurrence of Breast Cancer After MammoSite® Brachytherapy Voth M, Budway R, Keleher A, et al Am Surg 72:798-801, 2006 The authors reported 2 local recurrences outside the irradiated volume among 55 women treated with BCT including partial breast ir-
radiation using the MammoSite device for T1N0M0 breast cancer. Although important details are lacking in this report, including the actuarial local recurrence rate (crude rate of 2/55 = 3.6% was reported) and the median follow-up time for the entire cohort, this report clearly highlights the importance of the ongoing clinical trial regarding the role of partial breast irradiation. Appropriate selection of candidates for partial breast irradiation is clearly critical; however, selection criteria are not yet completely understood or defined. For example, it is not yet clear whether magnetic resonance imaging will be necessary to select patients for partial breast irradiation with truly unicentric disease, or if certain pathologic features may predict which patients would derive the most benefit from whole-breast irradiation. The true long-term local recurrence rates and toxicities are not yet known for MammoSite or external-beam partial breast irradiation. As with all new, untested treatment options, proceeding with caution and treating patients on trial seems critical to avoid compromising the outcomes of patients with curable breast cancer. W. A. Woodward MD, PhD
CHEMOTHERAPY 2–53
Effectiveness of switching from adjuvant tamoxifen to anastrozole in postmenopausal women with hormone-sensitive early-stage breast cancer: a meta-analysis Jonat W, Gnant M, Boccardo F, et al (Univ of Kiel, Germany; Med Univ of Vienna, Austria; Univ of Genoa, Italy; et al) Lancet Oncol 7:991-996, 2006
Background.—For more than 20 years, tamoxifen has been the mainstay of adjuvant endocrine therapy for women with hormone-sensitive early-stage breast cancer. However, not only does tamoxifen have potential side-effects such as an increased risk of endometrial cancer and thromboembolic events, but patients can also develop resistance to the drug. We aimed to investigate whether switching
treatment of postmenopausal women with such breast cancer to anastrozole after 2–3 years of tamoxifen would be more effective than continuing on tamoxifen for a total of 5 years. Methods.—We did a meta-analysis of three clinical trials—the Austrian Breast and Colorectal Cancer Study Group (ABCSG 8), Arimidex-Nolvadex (ARNO 95), and the Italian Tamoxifen Anastrozole (ITA) studies—in which postmenopausal women with histologically confirmed, hormone-sensitive earlystage breast cancer were randomised to 1 mg/day anastrozole (n=2009) after 2–3 years of tamoxifen treatment or to continued 20 or 30 mg/day tamoxifen (n=1997). We analysed the data with a stratified Cox proportional hazards model with the covariates of age, tumour size, nodal status, grade, surgery, and chemotherapy. Findings.—Patients who switched to anastrozole had fewer disease recurrences
(92 vs 159) and deaths (66 vs 90) than did those who remained on tamoxifen, resulting in significant improvements in disease-free survival (hazard ratio 0.59 [95% CI 0.48–0.74]; p<0.0001), eventfree survival (0.55 [0.42–0.71]; p<0.0001), distant recurrence-free survival (0.61 [0.45–0.83]; p=0.002), and overall survival (0.71 [0.52–0.98]; p=0.04). Interpretation.—Our results show that the clinical benefits in terms of eventfree survival seen in individual trials for those patients who switched to anastrozole translate into a benefit in overall survival. These findings confirm that clinicians should consider switching postmenopausal women who have taken adjuvant tamoxifen for 2–3 years to anastrozole. Please see the expert perspective by Tripathy.
®
Breast Diseases: A Year Book Quarterly Vol 18 No 2 2007
195 195
Local Recurrence of Breast Cancer After MammoSite® Brachytherapy Voth M, Budway R, Keleher A, et al Am Surg 72:798-801, 2006 The authors reported 2 local recurrences outside the irradiated volume among 55 women treated with BCT including partial breast ir-
radiation using the MammoSite device for T1N0M0 breast cancer. Although important details are lacking in this report, including the actuarial local recurrence rate (crude rate of 2/55 = 3.6% was reported) and the median follow-up time for the entire cohort, this report clearly highlights the importance of the ongoing clinical trial regarding the role of partial breast irradiation. Appropriate selection of candidates for partial breast irradiation is clearly critical; however, selection criteria are not yet completely understood or defined. For example, it is not yet clear whether magnetic resonance imaging will be necessary to select patients for partial breast irradiation with truly unicentric disease, or if certain pathologic features may predict which patients would derive the most benefit from whole-breast irradiation. The true long-term local recurrence rates and toxicities are not yet known for MammoSite or external-beam partial breast irradiation. As with all new, untested treatment options, proceeding with caution and treating patients on trial seems critical to avoid compromising the outcomes of patients with curable breast cancer. W. A. Woodward MD, PhD
CHEMOTHERAPY 2–53
Effectiveness of switching from adjuvant tamoxifen to anastrozole in postmenopausal women with hormone-sensitive early-stage breast cancer: a meta-analysis Jonat W, Gnant M, Boccardo F, et al (Univ of Kiel, Germany; Med Univ of Vienna, Austria; Univ of Genoa, Italy; et al) Lancet Oncol 7:991-996, 2006
Background.—For more than 20 years, tamoxifen has been the mainstay of adjuvant endocrine therapy for women with hormone-sensitive early-stage breast cancer. However, not only does tamoxifen have potential side-effects such as an increased risk of endometrial cancer and thromboembolic events, but patients can also develop resistance to the drug. We aimed to investigate whether switching
treatment of postmenopausal women with such breast cancer to anastrozole after 2–3 years of tamoxifen would be more effective than continuing on tamoxifen for a total of 5 years. Methods.—We did a meta-analysis of three clinical trials—the Austrian Breast and Colorectal Cancer Study Group (ABCSG 8), Arimidex-Nolvadex (ARNO 95), and the Italian Tamoxifen Anastrozole (ITA) studies—in which postmenopausal women with histologically confirmed, hormone-sensitive earlystage breast cancer were randomised to 1 mg/day anastrozole (n=2009) after 2–3 years of tamoxifen treatment or to continued 20 or 30 mg/day tamoxifen (n=1997). We analysed the data with a stratified Cox proportional hazards model with the covariates of age, tumour size, nodal status, grade, surgery, and chemotherapy. Findings.—Patients who switched to anastrozole had fewer disease recurrences
(92 vs 159) and deaths (66 vs 90) than did those who remained on tamoxifen, resulting in significant improvements in disease-free survival (hazard ratio 0.59 [95% CI 0.48–0.74]; p<0.0001), eventfree survival (0.55 [0.42–0.71]; p<0.0001), distant recurrence-free survival (0.61 [0.45–0.83]; p=0.002), and overall survival (0.71 [0.52–0.98]; p=0.04). Interpretation.—Our results show that the clinical benefits in terms of eventfree survival seen in individual trials for those patients who switched to anastrozole translate into a benefit in overall survival. These findings confirm that clinicians should consider switching postmenopausal women who have taken adjuvant tamoxifen for 2–3 years to anastrozole. Please see the expert perspective by Tripathy.
®
Breast Diseases: A Year Book Quarterly Vol 18 No 2 2007
195 195