Baker Sarah, Mou Benjamin, Jiang Will, Liu Mitchell, Bergman Alanah M, Schellenberg Devin, Alexander Abraham S, Carolan Hannah, Atrchian Siavash, Berrang Tanya, Bang Andrew, Chng Nick, Matthews Quinn, Tyldesley Scott, Olson Robert A
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 Dec 1;114(5):856-861. doi: 10.1016/j.ijrobp.2022.06.094. Epub 2022 Jul 13.
A subset of patients with oligometastatic cancer experience early widespread cancer dissemination and do not benefit from metastasis-directed therapy such as SABR. This study aimed to identify factors associated with early polymetastatic relapse (PMR).
The SABR-5 trial was a single arm phase 2 study conducted at all 6 regional cancer centers across British Columbia (BC), Canada. SABR for oligometastases was only offered on trial. Patients with up to 5 oligometastatic lesions (total, progressing, or induced) received SABR to all lesions. Patients were 18 years of age or older, Eastern Cooperative Oncology Group 0 to 2 and life expectancy ≥6 months. This secondary analysis evaluated factors associated with early PMR, defined as disease recurrence within 6 months of SABR, which is not amenable to further local treatment. Univariable and multivariable analyses were performed using binary logistic regression. The Kaplan-Meier method and log-rank tests assessed PMR-free survival and differences between risk groups, respectively.
Between November 2016 and July 2020, 381 patients underwent treatment on SABR-5. A total of 16% of patients experienced PMR. Worse performance status (Eastern Cooperative Oncology Group 1-2 vs 0; hazard ratio [HR] = 2.01, P = .018), nonprostate/breast histology (HR = 3.64, P <.001), and oligoprogression (HR = 3.84, P <.001) were independent predictors for early PMR. Risk groups were identified with median PMR-free survival ranging from 5 months to not yet reached at the time of analysis. Rates of 3-year overall survival were 0%, 53% (95% confidence interval [CI], 48-58), 77% (95% CI, 73-81), and 93% (95% CI, 90-96) in groups 1 to 4, respectively (P <.001).
Four distinct risk groups for early PMR are identified, which differ significantly in PMR-free survival and overall survival. The group with all 3 risk factors had a median PMR-free survival of 5 months and may not benefit from local ablative therapy alone. This model should be externally validated with data from other prospective trials.
一部分寡转移癌患者会早期出现广泛的癌症播散，无法从立体定向体部放疗（SABR）等转移灶定向治疗中获益。本研究旨在确定与早期多转移复发（PMR）相关的因素。
SABR-5试验是在加拿大不列颠哥伦比亚省（BC）所有6个地区癌症中心进行的单臂2期研究。仅在试验中提供针对寡转移灶的SABR。有多达5个寡转移病灶（总计、进展期或诱导性）的患者接受针对所有病灶的SABR治疗。患者年龄在18岁及以上，东部肿瘤协作组（ECOG）评分为0至2分，预期寿命≥6个月。这项二次分析评估了与早期PMR相关的因素，早期PMR定义为SABR治疗后6个月内疾病复发，且无法进行进一步的局部治疗。使用二元逻辑回归进行单变量和多变量分析。分别采用Kaplan-Meier方法和对数秩检验评估无PMR生存期及风险组之间的差异。
2016年11月至2020年7月期间，381例患者接受了SABR-5治疗。共有16%的患者出现PMR。较差的体能状态（ECOG 1-2分 vs 0分；风险比[HR]=2.01，P=0.018）、非前列腺/乳腺组织学类型（HR=3.64，P<0.001）和寡进展（HR=3.84，P<0.001）是早期PMR的独立预测因素。确定了风险组，其无PMR生存期的中位数从5个月到分析时仍未达到。1至4组的3年总生存率分别为0%、53%（95%置信区间[CI]，48-58）、77%（95%CI，73-81）和93%（95%CI，90-96）（P<0.001）。
确定了早期PMR的四个不同风险组，其无PMR生存期和总生存率存在显著差异。具有所有三个风险因素的组无PMR生存期的中位数为5个月，可能无法仅从局部消融治疗中获益。该模型应通过其他前瞻性试验的数据进行外部验证。
