Baker Sarah, Lechner Linden, Liu Mitchell, Chang Jee Suk, Cruz-Lim Ella Mae, Mou Ben, Jiang Will, Bergman Alanah, Schellenberg Devin, Alexander Abraham, Berrang Tanya, Bang Andrew, Chng Nick, Matthews Quinn, Carolan Hannah, Hsu Fred, Miller Stacey, Atrchian Siavash, Chan Elisa, Ho Clement, Mohamed Islam, Lin Angela, Huang Vicky, Mestrovic Ante, Hyde Derek, Lund Chad, Pai Howard, Valev Boris, Lefresne Shilo, Arbour Gregory, Yu Irene, Tyldesley Scott, Olson Rob A
University of British Columbia; BC Cancer-Surrey, Department of Radiation Oncology, Surrey, BC, Canada.
University of British Columbia.
Int J Radiat Oncol Biol Phys. 2024 Apr 1;118(5):1497-1506. doi: 10.1016/j.ijrobp.2024.01.008. Epub 2024 Jan 12.
The optimal sequencing of local and systemic therapy for oligometastatic cancer has not been established. This study retrospectively compared progression-free survival (PFS), overall survival (OS), and SABR-related toxicity between upfront versus delay of systemic treatment until progression in patients in the SABR-5 trial.
The single-arm phase 2 SABR-5 trial accrued patients with up to 5 oligometastases across SABR-5 between November 2016 and July 2020. Patients received SABR to all lesions. Two cohorts were retrospectively identified: those receiving upfront systemic treatment along with SABR and those for whom systemic treatment was delayed until disease progression. Patients treated for oligoprogression were excluded. Propensity score analysis with overlap weighting balanced baseline characteristics of cohorts. Bootstrap sampling and Cox regression models estimated the association of delayed systemic treatment with PFS, OS, and grade ≥2 toxicity.
A total of 319 patients with oligometastases underwent treatment on SABR-5, including 121 (38%) and 198 (62%) who received upfront and delayed systemic treatment, respectively. In the weighted sample, prostate cancer was the most common primary tumor histology (48%) followed by colorectal (18%), breast (13%), and lung (4%). Most patients (93%) were treated for 1 to 2 metastases. The median follow-up time was 34 months (IQR, 24-45). Delayed systemic treatment was associated with shorter PFS (hazard ratio [HR], 1.56; 95% CI, 1.15-2.13; P = .005) but similar OS (HR, 0.90; 95% CI, 0.51-1.59; P = .65) compared with upfront systemic treatment. Risk of grade 2 or higher SABR-related toxicity was reduced with delayed systemic treatment (odds ratio, 0.35; 95% CI, 0.15-0.70; P < .001).
Delayed systemic treatment is associated with shorter PFS without reduction in OS and with reduced SABR-related toxicity and may be a favorable option for select patients seeking to avoid initial systemic treatment. Efforts should continue to accrue patients to histology-specific trials examining a delayed systemic treatment approach.
寡转移癌局部和全身治疗的最佳顺序尚未确定。本研究回顾性比较了SABR-5试验中患者在全身治疗提前进行与延迟至疾病进展时的无进展生存期（PFS）、总生存期（OS）以及SABR相关毒性。
单臂2期SABR-5试验在2016年11月至2020年7月期间纳入了SABR-5试验中寡转移灶最多达5个的患者。患者对所有病灶均接受了立体定向体部放疗（SABR）。回顾性确定了两个队列：接受全身治疗同时进行SABR的患者，以及全身治疗延迟至疾病进展的患者。排除接受寡进展治疗的患者。采用倾向评分分析和重叠加权法平衡队列的基线特征。通过自助抽样和Cox回归模型估计延迟全身治疗与PFS、OS及≥2级毒性之间的关联。
共有319例寡转移患者接受了SABR-5治疗，其中分别有121例（38%）和198例（62%）接受了提前和延迟全身治疗。在加权样本中，前列腺癌是最常见的原发肿瘤组织学类型（48%），其次是结直肠癌（18%）、乳腺癌（13%）和肺癌（4%）。大多数患者（93%）接受了1至2个转移灶的治疗。中位随访时间为34个月（四分位间距，24 - 45个月）。与提前全身治疗相比，延迟全身治疗与较短的PFS相关（风险比[HR]，1.56；95%置信区间，1.15 - 2.13；P = 0.005），但OS相似（HR，0.90；95%置信区间，0.51 - 1.59；P = 0.65）。延迟全身治疗降低了2级或更高SABR相关毒性的风险（优势比，0.35；95%置信区间，0.15 - 0.70；P < 0.001）。
延迟全身治疗与较短的PFS相关，但OS无降低，且SABR相关毒性降低，可能是部分希望避免初始全身治疗患者的有利选择。应继续努力招募患者参加针对延迟全身治疗方法的组织学特异性试验。
