NCCN VERSION 2 2015

NCCN Guidelines Version 2.2015 Breast Cancer

NCCN Guidelines Index Breast Cancer Table of Contents Discussion

re-excision should be considered for a higher radiation boost dose to the tumor bed. Several studies of women with early-stage breast cancer treated with breast-conserving therapy have identified young age as a significant predictor of an increased likelihood of IBTR after breast-conserving surgery. 110-113 Risk factors, such as a family history of breast cancer or a genetic predisposition for breast cancer (eg, BRCA1/2 or other mutation), are more likely to exist in the population of young women with breast cancer, thereby confounding the independent contributions of age and treatment to clinical outcome. 114 Survival outcomes for young women with breast cancer receiving either lumpectomy or mastectomy are similar. 115 Several studies have been reported using accelerated partial breast irradiation (APBI) rather than whole breast irradiation following complete surgical excision of in-breast disease. The panel generally views the use of APBI as investigational, and encourages its use within the confines of a high-quality, prospective clinical trial. 116 For patients who are not trial eligible, recommendations from the American Society for Radiation Oncology (ASTRO) indicate that APBI may be suitable in selected patients with early-stage breast cancer and may be comparable to treatment with standard whole-breast RT. 117 Patients who may be suitable for APBI are women 60 years of age and older who are not carriers of a known BRCA1/2 mutation and have been treated with primary surgery for a unifocal stage I, ER-positive cancer. Tumors should be infiltrating ductal or have a favorable histology, should not be associated with an extensive intraductal component or LCIS, and should have negative margins. Thirty-four Gy in 10 fractions delivered twice per day with brachytherapy or 38.5 Gy in 10 fractions delivered twice per day with external beam photon therapy to the tumor

bed is recommended. Other fractionation schemes are under investigation. Studies have suggested that the ASTRO stratification guidelines may not adequately predict IBTR following APBI. 118,119 Follow-up is limited and studies are ongoing. Only limited data are available on the survival impact of mastectomy contralateral to a unilateral breast cancer. 120 Analysis of women included in the SEER database treated with mastectomy for a unilateral breast cancer from 1998 to 2003 showed that contralateral mastectomy performed at the time of treatment of a unilateral cancer was associated with a reduction in breast cancer-specific mortality only in the population of young women (18–49 years of age) with stage I/II, ER-negative breast cancer (HR, 0.68; 95% CI, 0.53–0.88; P = .004). 121 The 5 year breast cancer survival for this group was slightly improved with contralateral mastectomy vs. without (88.5% vs 83.7%, difference = 4.8%). 121 The panel recommends that women with breast cancer who are ≤35 years or premenopausal and carriers of a known BRCA1/2 mutation consider additional risk reduction strategies following appropriate risk assessment and counseling (see NCCN Guidelines for Breast Risk Reduction and NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast and Ovarian ). This process should involve multidisciplinary consultations prior to surgery, and should include a discussion of the risks associated with development of a contralateral breast cancer as compared with the risks associated with recurrent disease from the primary cancer. Except as specifically outlined in these guidelines, prophylactic mastectomy of a breast contralateral to a known unilateral breast cancer treated with mastectomy is discouraged by the panel. The use of a prophylactic mastectomy contralateral to a breast treated with breast-conserving surgery is very strongly discouraged in all patients.

Version 2.2015, 03/11/15 © National Comprehensive Cancer Network, Inc. 2015, All rights reserved. The NCCN Guidelines® and this illustration may not be reproduced in any form without the express written permission of NCCN®. MS-14