两毫米！外科肿瘤学会、美国放射肿瘤学会、美国临床肿瘤学会导管原位癌全乳放疗＋保乳手术切缘共识指南

　　2016年8月15日，美国临床肿瘤学会官方期刊《临床肿瘤学杂志》在线发表纪念斯隆-凯特林癌症中心、阿尔伯特·爱因斯坦医疗网络、德克萨斯大学MD安德森癌症中心、哈佛大学医学院、杜克大学医学中心、苏珊科曼乳腺癌基金会、斯坦福大学医学院、耶鲁大学医学院、悉尼大学公共卫生学院与医学院起草的外科肿瘤学会、美国放射肿瘤学会、美国临床肿瘤学会导管原位癌全乳放疗＋保乳手术切缘共识指南。

　　由于全乳放疗＋保乳手术治疗乳腺导管原位癌的最佳阴性切缘宽度仍然存在争议，故该多学科共识小组采用了切缘宽度和患侧乳腺肿瘤复发的荟萃分析（来自包括7883例患者的20项研究系统回顾以及其他公开发表文献）作为共识的循证基础。

　　结果发现：与阳性切缘（定义为导管原位癌墨染）相比，阴性切缘可使患侧乳腺肿瘤复发风险减半；与更小的阴性切缘相比，2mm阴性切缘可使患侧乳腺肿瘤复发风险最小化；与2mm阴性切缘相比，更大的阴性切缘并不显著减少患侧乳腺肿瘤复发；阴性切缘少于2mm并非乳房切除术的独立指征，在确定再切除必要性时，还应考虑影响患侧乳腺肿瘤复发率的已知因素。

　　因此，将2mm切缘作为联合全乳放疗治疗导管原位癌时的足够切缘标准，与患侧乳腺肿瘤复发率低有相关性，并且可能降低再切除率、改善整形效果、降低医疗成本。临床经验应被用于确定阴性切缘＜2毫米的患者是否需要进一步手术。

J Clin Oncol. 2016 Aug 15. [Epub ahead of print]

Society of Surgical Oncology - American Society for Radiation Oncology - American Society of Clinical Oncology Consensus Guideline on Margins for Breast-Conserving Surgery With Whole-Breast Irradiation in Ductal Carcinoma In Situ.

Monica Morrow, Kimberly J. Van Zee, Lawrence J. Solin, Nehmat Houssami, Mariana Chavez-MacGregor, Jay R. Harris, Janet Horton, Shelley Hwang, Peggy L. Johnson, M. Luke Marinovich, Stuart J. Schnitt, Irene Wapnir, Meena S. Moran.

Breast Service, Memorial Sloan Kettering Cancer Center, New York, NY; Albert Einstein Healthcare Network, Philadelphia, PA; University of Texas MD Anderson Cancer Center, Houston, TX; Harvard Medical School, Boston, MA; Duke University Medical Center, Durham, NC; Advocate in Science, Susan G. Komen, Kansas City, KS; Stanford University School of Medicine, Stanford, CA; Yale School of Medicine, Yale University, New Haven, CT; Screening and Test Evaluation Program (STEP), Sydney School of Public Health, Sydney Medical School, The University of Sydney, New South Wales, Australia.

BACKGROUND: Controversy exists regarding the optimal negative margin width for ductal carcinoma in situ (DCIS) treated with breast-conserving surgery and whole-breast irradiation (WBRT).

METHODS: A multidisciplinary consensus panel used a meta-analysis of margin width and ipsilateral breast tumor recurrence (IBTR) from a systematic review of 20 studies including 7883 patients and other published literature as the evidence base for consensus.

RESULTS: Negative margins halve the risk of IBTR compared with positive margins defined as ink on DCIS. A 2 mm margin minimizes the risk of IBTR compared with smaller negative margins. More widely clear margins do not significantly decrease IBTR compared with 2 mm margins. Negative margins less than 2 mm alone are not an indication for mastectomy, and factors known to impact rates of IBTR should be considered in determining the need for re-excision.

CONCLUSION: The use of a 2 mm margin as the standard for an adequate margin in DCIS treated with WBRT is associated with low rates of IBTR and has the potential to decrease re-excision rates, improve cosmetic outcome, and decrease health care costs. Clinical judgment should be used in determining the need for further surgery in patients with negative margins < 2 mm.

FUNDING: Susan G. Komen; National Breast Cancer Foundation (NBCF; NBCF Australia) Breast Cancer Research Leadership Fellowship; Cancer Institute New South Wales Fellowship.

This guideline was developed through collaboration between the Society of Surgical Oncology, the American Society of Clinical Oncology, and the American Society for Radiation Oncology, and is published jointly by invitation and consent in the Annals of Surgical Oncology, Journal of Clinical Oncology, and Practical Radiation Oncology.

This statement has been endorsed by the Board of Directors of the American Society of Breast Surgeons.

DOI: 10.1200/JCO.2016.68.3573