【原】乳腺癌术后辅助放疗时限影响生存结局

　　为了优化乳腺癌的医疗，美国外科医师学会癌症委员会制定了关于术后辅助放疗指征和时限的质量指标。其中，MASTRT质量指标规定对于引流区域阳性淋巴结≥4枚的乳房切除术后女性，应于乳腺癌诊断1年（365天）内推荐或给予放疗；BCSRT质量指标规定对于70岁以下的保乳术后女性，应于乳腺癌诊断1年（365天）内给予放疗。

　　2020年3月17日，美国乳腺外科医师学会和美国肿瘤外科学会《肿瘤外科学报》在线发表美国希望之城国家医学中心、加拿大麦吉尔大学的研究报告，分析了美国外科医师学会癌症委员会乳腺癌术后辅助放疗指征和时限的质量指标全国实施情况，及其对患者总生存结局的影响。

　　该研究通过国家癌症研究所（NCI）全国癌症数据库（NCDB）对2004～2012年被诊断为乳腺浸润癌的28万5291例患者进行回顾分析。针对III期乳腺癌伴阳性淋巴结≥4枚的乳房切除术后患者、I～III期乳腺癌保乳术后患者，判断是否符合乳腺癌诊断后365天内给予放疗的质量指标。通过单因素和多因素逻辑回归、多因素比例风险模型，对影响患者依从性和总生存的相关因素进行评定。

　　结果，对于乳房切除队列，及时放疗患者占66.9%

• 及时放疗与未行放疗相比：总死亡风险低30%（风险比：0.70，95%置信区间：0.67～0.73）

• 延迟放疗与未行放疗相比：总死亡风险低26%（风险比：0.74，95%置信区间：0.65～0.85）

• 延迟放疗与及时放疗相比：总死亡风险相似（风险比：1.07，95%置信区间：0.93～1.23）

　　对于保乳手术队列，及时放疗患者占89.4%

• 及时放疗与未行放疗相比：总死亡风险低53%（风险比：0.47，95%置信区间：0.45～0.49）

• 延迟放疗与未行放疗相比：总死亡风险低36%（风险比：0.64，95%置信区间：0.56～0.74）

• 延迟放疗与及时放疗相比，总死亡风险高37%（风险比：1.37，95%置信区间：1.19～1.58）

　　影响患者依从性的相关因素包括医疗保险类型和距离医院远近。

　　因此，该研究结果表明，乳房切除术后无论何时进行辅助放疗，都可改善总生存。不过，保乳术后辅助放疗及时性确实影响总生存。针对影响患者依从性的可改变因素，例如医疗服务便利性，可能改善患者依从性和总生存。

Ann Surg Oncol. 2020 Mar 17. [Epub ahead of print]

Time to Adjuvant Radiotherapy in Breast Cancer Affects Survival: Implications for the American College of Surgeons Commission on Cancer Quality Metrics.

Vasilena Zheleva, Rebecca A. Nelson, Sinziana Dumitra, Nayana L. Vora, Lily L. Lai.

City of Hope National Medical Center, Duarte, CA, USA; McGill University, Montreal, QC, Canada.

BACKGROUND: To optimize breast cancer care, the American College of Surgeons Commission on Cancer developed quality measures regarding receipt and timing of adjuvant radiotherapy (RT). Nationwide compliance with these measures and its impact on overall survival (OS) are evaluated herein.

PATIENTS AND METHODS: Patients (n=285,291) diagnosed with invasive breast cancer from 2004 to 2012 were identified from the National Cancer Database. Compliance with RT administration within 365 days from diagnosis was determined for patients with stage III disease with≥4 positive lymph nodes post mastectomy and stage I-III disease post breast-conserving surgery (BCS). Univariate and multivariate logistic regression and Cox proportional hazard models were used to assess factors associated with compliance and OS, respectively.

RESULTS: In the mastectomy cohort, 66.9% received timely RT, showing improved OS versus no RT patients (HR 0.70, 95% CI 0.67-0.73). Delayed RT patients (≥365 days) achieved equivalent OS to those receiving timely RT (HR 1.07, 95% CI 0.93-1.23) and superior OS to no RT patients (HR 0.74, 95% CI 0.65-0.85). In the BCS cohort, 89.4% received timely RT, showing improved OS versus no RT patients (HR 0.47, 95% CI 0.45-0.49). Delayed RT was associated with improved OS versus no RT (HR 0.64, 95% CI 0.56-0.74) and decreased OS versus timely RT (HR 1.37, 95% CI 1.19-1.58). Factors associated with noncompliance included insurance type and distance to hospital.

CONCLUSIONS: Quality measure compliance with adjuvant RT improves OS, regardless of timing after mastectomy. However, timeliness does impact OS after BCS. Focus on modifiable factors to improve compliance such as access to care may lead to improved compliance and OS.

DOI: 10.1245/s10434-020-08326-8