Hsu Fred, Sit Daegan, Pastuch Andrea, Dingler Angie, Atwal Parmveer
Abbotsford Centre, Department of Radiation Oncology, BC Cancer Agency, Abbotsford, British Columbia, Canada.
Vancouver Cancer Centre, Department of Radiation Oncology, BC Cancer Agency, Vancouver, British Columbia. Canada.
Clin Transl Radiat Oncol. 2021 Jul 1;30:15-18. doi: 10.1016/j.ctro.2021.06.006. eCollection 2021 Sep.
To examine the impact of epidermal growth factor receptor (EGFR) mutations on objective response to palliative lung radiotherapy in patients with metastatic non-small cell lung cancer (NSCLC).
A multicentre retrospective study was conducted of patients with metastatic NSCLC diagnosed between March 2010 and June 2012 who received palliative radiotherapy to the chest. Patients included for study had baseline imaging and follow-up imaging 1-3 months after radiotherapy. The primary endpoint was 1-3 month local objective imaging response by the Response Evaluation Criteria in Solid Tumours (RECIST). Patients were divided into EGFR mutation positive (EGFR+) and EGFR wild type (WT) cohorts for analysis.
There were 121 patients for study inclusion: 89 (74%) were EGFR WT and 32 (26%) were EGFR+. The response rate between EGFR WT and EGFR+ cohorts was not significantly different (49 vs. 63%, p = 0.21). On multivariate analysis, initiation of a tyrosine kinase inhibitor (TKI) after radiotherapy was associated with a higher rate of response (OR: 5.07, 95%CI: 1.08-23.69, p = 0.039) but EGFR mutation status was not. For the EGFR+ cohort, patients with disease progression after initial management on a TKI had a worse response rate compared to patients who were TKI-naïve before starting radiotherapy (30 vs. 77%, p = 0.018). Local control was not statistically different between the EGFR cohorts.
The EGFR mutation status alone was not an independent predictor of objective radiographic response to palliative thoracic radiotherapy. Acquired resistance to TKI therapy may be associated with disease cross-resistance to palliative radiotherapy.
探讨表皮生长因子受体（EGFR）突变对转移性非小细胞肺癌（NSCLC）患者姑息性肺部放疗客观缓解的影响。
对2010年3月至2012年6月期间诊断为转移性NSCLC且接受胸部姑息性放疗的患者进行了一项多中心回顾性研究。纳入研究的患者在放疗后1 - 3个月有基线影像学检查和随访影像学检查。主要终点是根据实体瘤疗效评价标准（RECIST）评估的1 - 3个月局部客观影像学缓解情况。将患者分为EGFR突变阳性（EGFR+）和EGFR野生型（WT）队列进行分析。
共有121例患者纳入研究：89例（74%）为EGFR WT，32例（26%）为EGFR+。EGFR WT和EGFR+队列之间的缓解率无显著差异（49%对63%，p = 0.21）。多因素分析显示，放疗后开始使用酪氨酸激酶抑制剂（TKI）与更高的缓解率相关（OR：5.07，95%CI：1.08 - 23.69，p = 0.039），但EGFR突变状态并非如此。对于EGFR+队列，在初始接受TKI治疗后疾病进展的患者与放疗前未接受过TKI治疗的患者相比，缓解率更差（30%对77%，p = 0.018）。EGFR队列之间的局部控制在统计学上无差异。
单独的EGFR突变状态并非姑息性胸部放疗客观影像学缓解的独立预测因素。对TKI治疗获得性耐药可能与疾病对姑息性放疗交叉耐药有关。
