Purpose/Objective(s)To describe the regional recurrence rate and identify the prognostic factors associated regional recurrence for patients with N1 breast cancer after breast-conserving surgery.Materials/MethodsFrom June 1996 to December 2008, 570 patients with nonmetastatic pTx-3N1a breast cancer underwent lumpectomy (n = 432) or quadrantectomy (n = 41) with axillary dissection (sentinel node biopsy alone, n = 81; level I, n = 117; level I and II, n = 260; others, n = 112) followed by adjuvant radiation therapy. No patient received preoperative chemotherapy. Radiation therapy consisted of median 50.4 Gy to the entire breast via tangential fields using 4-6 Mv photon beam. A total of 10 to 15 Gy of boost dose was delivered to the primary site. Thirty-five patients received 45 Gy at 1.8 Gy to the axillary and supraclavicular area. Eleven patients received median 45 Gy at 1.8 Gy to internal mammary lymph node area. Adjuvant systemic chemotherapy was administered in 549 patients. Adjuvant hormone therapy was administered in 442 patients. Survival time was estimated using Kaplan-Meier method. Risk factors for regional recurrence were assessed using a multivariable Cox proportional hazards model.ResultsMedian follow-up was 89.6 months (range, 10.6-263.7); median age was 46 years (range, 21-76). Tumor stage was pT1x in 2, pT1mic in 2, pT1a in 6, pT1b in 59, pT1c in 287, pT2 in 211, and pT3 in 3 patients. Median tumor size was 1.8 cm. All except 22 patients were diagnosed with invasive ductal carcinoma. Estrogen and progesterone receptors were positive in 401 and 389 patients, respectively. Lymphovascular invasion was discovered in 122 patients. 5-year ipsilateral breast tumor recurrence rate was 9.6%, regional recurrence rate was 10.4%, and distant metastasis rate was 10.0%. 5-year disease free survival and overall survival rates were 86.8% and 96.0%, respectively. Multivariate analysis showed that lymphovascular invasion (hazard ratio (HR) = 2.66, p = 0.021), and hormone receptor (HR = 0.41, p = 0.045) were significant risk factors for regional recurrence, while histologic grade had borderline significance (HR = 2.24, p = 070).ConclusionsLymphovascular invasion, hormone receptor status, and histologic grade were prognostic factors for regional recurrence after breast conserving surgery among patients with pN1a breast cancer. Prospective studies to further investigate the potential benefit of adjuvant radiation therapy to supraclavicular area or internal mammary region in these women are warranted. Purpose/Objective(s)To describe the regional recurrence rate and identify the prognostic factors associated regional recurrence for patients with N1 breast cancer after breast-conserving surgery. To describe the regional recurrence rate and identify the prognostic factors associated regional recurrence for patients with N1 breast cancer after breast-conserving surgery. Materials/MethodsFrom June 1996 to December 2008, 570 patients with nonmetastatic pTx-3N1a breast cancer underwent lumpectomy (n = 432) or quadrantectomy (n = 41) with axillary dissection (sentinel node biopsy alone, n = 81; level I, n = 117; level I and II, n = 260; others, n = 112) followed by adjuvant radiation therapy. No patient received preoperative chemotherapy. Radiation therapy consisted of median 50.4 Gy to the entire breast via tangential fields using 4-6 Mv photon beam. A total of 10 to 15 Gy of boost dose was delivered to the primary site. Thirty-five patients received 45 Gy at 1.8 Gy to the axillary and supraclavicular area. Eleven patients received median 45 Gy at 1.8 Gy to internal mammary lymph node area. Adjuvant systemic chemotherapy was administered in 549 patients. Adjuvant hormone therapy was administered in 442 patients. Survival time was estimated using Kaplan-Meier method. Risk factors for regional recurrence were assessed using a multivariable Cox proportional hazards model. From June 1996 to December 2008, 570 patients with nonmetastatic pTx-3N1a breast cancer underwent lumpectomy (n = 432) or quadrantectomy (n = 41) with axillary dissection (sentinel node biopsy alone, n = 81; level I, n = 117; level I and II, n = 260; others, n = 112) followed by adjuvant radiation therapy. No patient received preoperative chemotherapy. Radiation therapy consisted of median 50.4 Gy to the entire breast via tangential fields using 4-6 Mv photon beam. A total of 10 to 15 Gy of boost dose was delivered to the primary site. Thirty-five patients received 45 Gy at 1.8 Gy to the axillary and supraclavicular area. Eleven patients received median 45 Gy at 1.8 Gy to internal mammary lymph node area. Adjuvant systemic chemotherapy was administered in 549 patients. Adjuvant hormone therapy was administered in 442 patients. Survival time was estimated using Kaplan-Meier method. Risk factors for regional recurrence were assessed using a multivariable Cox proportional hazards model. ResultsMedian follow-up was 89.6 months (range, 10.6-263.7); median age was 46 years (range, 21-76). Tumor stage was pT1x in 2, pT1mic in 2, pT1a in 6, pT1b in 59, pT1c in 287, pT2 in 211, and pT3 in 3 patients. Median tumor size was 1.8 cm. All except 22 patients were diagnosed with invasive ductal carcinoma. Estrogen and progesterone receptors were positive in 401 and 389 patients, respectively. Lymphovascular invasion was discovered in 122 patients. 5-year ipsilateral breast tumor recurrence rate was 9.6%, regional recurrence rate was 10.4%, and distant metastasis rate was 10.0%. 5-year disease free survival and overall survival rates were 86.8% and 96.0%, respectively. Multivariate analysis showed that lymphovascular invasion (hazard ratio (HR) = 2.66, p = 0.021), and hormone receptor (HR = 0.41, p = 0.045) were significant risk factors for regional recurrence, while histologic grade had borderline significance (HR = 2.24, p = 070). Median follow-up was 89.6 months (range, 10.6-263.7); median age was 46 years (range, 21-76). Tumor stage was pT1x in 2, pT1mic in 2, pT1a in 6, pT1b in 59, pT1c in 287, pT2 in 211, and pT3 in 3 patients. Median tumor size was 1.8 cm. All except 22 patients were diagnosed with invasive ductal carcinoma. Estrogen and progesterone receptors were positive in 401 and 389 patients, respectively. Lymphovascular invasion was discovered in 122 patients. 5-year ipsilateral breast tumor recurrence rate was 9.6%, regional recurrence rate was 10.4%, and distant metastasis rate was 10.0%. 5-year disease free survival and overall survival rates were 86.8% and 96.0%, respectively. Multivariate analysis showed that lymphovascular invasion (hazard ratio (HR) = 2.66, p = 0.021), and hormone receptor (HR = 0.41, p = 0.045) were significant risk factors for regional recurrence, while histologic grade had borderline significance (HR = 2.24, p = 070). ConclusionsLymphovascular invasion, hormone receptor status, and histologic grade were prognostic factors for regional recurrence after breast conserving surgery among patients with pN1a breast cancer. Prospective studies to further investigate the potential benefit of adjuvant radiation therapy to supraclavicular area or internal mammary region in these women are warranted. Lymphovascular invasion, hormone receptor status, and histologic grade were prognostic factors for regional recurrence after breast conserving surgery among patients with pN1a breast cancer. Prospective studies to further investigate the potential benefit of adjuvant radiation therapy to supraclavicular area or internal mammary region in these women are warranted.