早期乳腺癌术中放疗的五年结局回顾
术中放疗可在手术中直视下对肿瘤局部进行单次大剂量放疗，与术后全乳放疗相比，具有缩短疗程、有效保护正常组织的优势，已被用于低风险早期乳腺癌患者。不过，前瞻随机对照研究结果表明，术中放疗与术后全乳放疗相比复发风险较高。
2021年1月12日，美国肿瘤外科学会和美国乳腺外科医师学会《肿瘤外科学报》在线发表克利夫兰医学中心、印第安纳社区医疗网络、莫菲特癌症中心、西北纪念医院罗伯特卢里综合癌症中心、佛罗里达大学、萨凡纳纪念大学医疗中心、圣约翰河滨医院、蒙特菲奥雷医疗中心、圣塔拉多罗西霍法综合乳腺中心、玛格丽特公主癌症中心、萨特癌症中心、伊诺瓦费尔法克斯医院、乔治城大学医院、圣卢克大学医疗网络、芝加哥洛约拉大学斯特里奇医学院的TARGIT-R研究报告，对北美临床实践真实世界非随机对照早期乳腺癌术中放疗的5年随访结果进行了回顾分析。
该多中心登记数据库回顾研究对2007～2013年北美19家医院保乳术中放疗非随机对照患者进行回顾分析，主要结局为同侧乳腺肿瘤复发。
结果，患者共计667例，中位随访5.1年，其中：
首次术中放疗：72%
延迟术中放疗：3%
首次术中放疗＋按计划术后全乳放疗：8%
首次术中放疗＋计划外术后全乳放疗：17%
第5年时，全部患者的同侧乳腺肿瘤复发率为6.6%，其中：
首次术中放疗：8%
延迟术中放疗：0
首次术中放疗＋按计划术后全乳放疗：0
首次术中放疗＋计划外术后全乳放疗：1.7%
坚持与未坚持内分泌治疗的患者相比，同侧乳腺肿瘤复发风险高3.67倍。坚持内分泌治疗的首次术中放疗患者同侧乳腺肿瘤复发率为3.9%。
因此，该回顾研究与前瞻随机对照研究相比，局部复发率略有不同，并且显著高于既往已经发表的早期乳腺癌类似患者全乳放疗研究。了解该回顾研究与前瞻随机对照研究的差异，对于优化患者选择和将来结局至关重要。
相关链接
Ann Surg Oncol. 2021 Jan 12. Online ahead of print.
TARGIT-R (Retrospective): 5-Year Follow-Up Evaluation of Intraoperative Radiation Therapy (IORT) for Breast Cancer Performed in North America.
Valente SA, Tendulkar RD, Cherian S, Shah C, Ross DL, Lottich SC, Laronga C, Broman KK, Donnelly ED, Bethke KP, Shaw C, Lockney NA, Pederson A, Rudolph R, Hasselle M, Kelemen P, Hermanto U, Ashikari A, Kang S, Hoefer RA, McCready D, Fyles A, Escallon J, Rohatgi N, Graves J, Graves G, Willey SC, Tousimis E, Riley L, Deb N, Tu C, Small W Jr, Grobmyer SR.
Cleveland Clinic, Cleveland, OH, USA; Community Physician Network Breast Care, Community Health Network, Indianapolis, IN, USA; Moffitt Cancer Center, Tampa, FL, USA; Northwestern Memorial Hospital, Robert H. Lurie Comprehensive Cancer Center, Chicago, IL, USA; University of Florida, Gainsville, FL, USA; Memorial University Medical Center, Savannah, GA, USA; St. Johns Riverside Hospital, Dobbs Ferry, NY, USA; Montefiore Medical Center, Yonkers, NY, USA; The Sentara Dorothy G. Hoefer Comprehensive Breast Center, Newport News, VA, USA; Princess Margaret Cancer Centre, Toronto, OR, USA; Sutter Cancer Center, Sacramento, CA, USA; Inova Fairfax Hospital, Fairfax, VA, USA; Medstar Georgetown University Hospital, Washington, DC, USA; St. Luke's University Health Network, Bethlehem, PA, USA; Loyola University Chicago, Stritch School of Medicine, Maywood, IL, USA; Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates.
BACKGROUND: Intraoperative radiation therapy (IORT) has been investigated for patients with low-risk, early-stage breast cancer. The The North American experience was evaluated by TARGIT-R (retrospective) to provide outcomes for patients treated in "real-world" clinical practice with breast IORT. This analysis presents a 5-year follow-up assessment.
METHODS: TARGIT-R is a multi-institutional retrospective registry of patients who underwent lumpectomy and IORT between the years 2007 and 2013. The primary outcome of the evaluation was ipsilateral breast tumor recurrence (IBTR).
RESULTS: The evaluation included 667 patients with a median follow-up period of 5.1 years. Primary IORT (IORT at the time of lumpectomy) was performed for 72%, delayed IORT (after lumpectomy) for 3%, intended boost for 8%, and unintended boost (primary IORT followed by whole-breast radiation) for 17% of the patients. At 5 years, IBTR was 6.6% for all the patients, with 8% for the primary IORT cohort and 1.7% for the unintended-boost cohort. No recurrences were identified in the delayed IORT or intended-boost cohorts. Noncompliance with endocrine therapy (ET) was associated with higher IBTR risk (hazard ratio [HR], 3.67). Patients treated with primary IORT who were complaint with ET had a 5-year IBTR rate of 3.9%.
CONCLUSION: The local recurrence rates in this series differ slightly from recent results of randomized IORT trials and are notably higher than in previous published studies using whole-breast radiotherapy for similar patients with early-stage breast cancer. Understanding differences in this retrospective series and the prospective trials will be critical to optimizing patient selection and outcomes going forward.
PMID: 33433786
DOI: 10.1245/s10434-020-09432-3