Department of Radiation Oncology, University of British Columbia, Canada; Department of Radiation Oncology, BC Cancer - Surrey, Canada.
Department of Radiation Oncology, University of British Columbia, Canada; Department of Radiation Oncology, BC Cancer - Kelowna, Canada.
Int J Radiat Oncol Biol Phys. 2022 Nov 15;114(4):617-626. doi: 10.1016/j.ijrobp.2022.05.033. Epub 2022 Jun 3.
Despite increasing utilization of SABR for oligometastatic cancer, prospective outcomes are lacking. The purpose of this study was to determine progression-free survival (PFS), local control (LC), and prognostic factors from the population-based phase 2 SABR-5 trial.
The SABR-5 trial was a single-arm phase 2 study with the primary endpoint of toxicity, conducted at the 6 regional cancer centers across British Columbia (BC), Canada, during which time SABR for oligometastases was only offered on trial. Patients with up to 5 oligometastases (total or not controlled by prior treatment and including induced oligometastatic disease) underwent SABR to all lesions. Patients were 18 years of age or older, had an Eastern Cooperative Oncology Group score of 0 to 2, and had life expectancy ≥ 6 months. The secondary outcomes of PFS and LC are presented here.
Between November 2016 and July 2020, 381 patients underwent SABR on trial. Median follow-up was 27 months (interquartile range, 18-36). Median PFS was 15 months (95% confidence interval [CI], 12-18). LC at 1 and 3 years were 93% (95% CI, 91-95) and 87% (95% CI, 84-90), respectively. On multivariable analysis, increasing tumor diameter (hazard ratio [HR], 1.09; P < .001), declining performance status (HR, 2.13; P < .001), disease-free interval <18 months (HR, 1.52; P = .003), 4 or more metastases at SABR (HR, 1.48; P = .048), initiation or change in systemic treatment (HR, 0.50; P < .001), and oligoprogression (HR, 1.56; P = .008) were significant independent predictors of PFS. Tumor diameter (sub-hazard ratio [SHR], 1.28; P < .001), colorectal histology (SHR, 4.33; P = .002), and "other" histology (SHR, 3.90; P < .001) were associated with worse LC.
In this population-based cohort including patients with genuine oligometastatic, oligoprogressive, and induced oligometastatic disease, the median PFS was 15 months and LC at 3 years was 87%. This supports ongoing efforts to randomize patients in phase 3 trials, even outside the original 1 to 5 metachronous oligometastatic paradigm.
尽管立体定向消融放疗（SABR）在寡转移癌中的应用日益增多，但前瞻性结果仍缺乏。本研究旨在确定基于人群的 SABR-5 试验的无进展生存期（PFS）、局部控制率（LC）和预后因素。
SABR-5 试验是一项单臂 2 期研究，主要终点为毒性，在加拿大不列颠哥伦比亚省（BC）的 6 个区域癌症中心进行，在此期间，仅在试验中提供寡转移的 SABR。最多有 5 个寡转移灶（总数或先前治疗未控制，包括诱导性寡转移疾病）的患者接受所有病灶的 SABR。患者年龄在 18 岁或以上，东部合作肿瘤学组（ECOG）评分 0-2 分，预期寿命≥6 个月。此处报告 PFS 和 LC 的次要结果。
2016 年 11 月至 2020 年 7 月，381 例患者接受了试验中的 SABR。中位随访时间为 27 个月（四分位间距，18-36）。中位 PFS 为 15 个月（95%置信区间，12-18）。1 年和 3 年的 LC 分别为 93%（95%置信区间，91-95）和 87%（95%置信区间，84-90）。多变量分析显示，肿瘤直径增大（风险比[HR]，1.09；P<0.001）、体力状况下降（HR，2.13；P<0.001）、无疾病间期<18 个月（HR，1.52；P=0.003）、SABR 时 4 个或更多转移灶（HR，1.48；P=0.048）、起始或改变全身治疗（HR，0.50；P<0.001）和寡进展（HR，1.56；P=0.008）是 PFS 的显著独立预测因素。肿瘤直径（亚风险比[SHR]，1.28；P<0.001）、结直肠癌组织学（SHR，4.33；P=0.002）和“其他”组织学（SHR，3.90；P<0.001）与较差的 LC 相关。
在这项包括真正的寡转移、寡进展和诱导性寡转移疾病患者的基于人群的队列中，中位 PFS 为 15 个月，3 年 LC 为 87%。这支持了在 3 期试验中对患者进行随机分组的持续努力，即使是在最初的 1 到 5 个同步寡转移的范式之外。
