Stereotactic Ablative Radiotherapy for the Comprehensive Treatment of Oligometastatic Cancers: Long-Term Results of the SABR-COMET Phase II Randomized Trial
- PMID: 32484754
- PMCID: PMC7460150
- DOI: 10.1200/JCO.20.00818
Stereotactic Ablative Radiotherapy for the Comprehensive Treatment of Oligometastatic Cancers: Long-Term Results of the SABR-COMET Phase II Randomized Trial
Abstract
Purpose: The oligometastatic paradigm hypothesizes that patients with a limited number of metastases may achieve long-term disease control, or even cure, if all sites of disease can be ablated. However, long-term randomized data that test this paradigm are lacking.
Methods: We enrolled patients with a controlled primary malignancy and 1-5 metastatic lesions, with all metastases amenable to stereotactic ablative radiotherapy (SABR). We stratified by the number of metastases (1-3 v 4-5) and randomized in a 1:2 ratio between palliative standard-of-care (SOC) treatments (arm 1) and SOC plus SABR (arm 2). We used a randomized phase II screening design with a primary end point of overall survival (OS), using an α of .20 (wherein P < .20 indicates a positive trial). Secondary end points included progression-free survival (PFS), toxicity, and quality of life (QOL). Herein, we present long-term outcomes from the trial.
Results: Between 2012 and 2016, 99 patients were randomly assigned at 10 centers internationally. The most common primary tumor types were breast (n = 18), lung (n = 18), colorectal (n = 18), and prostate (n = 16). Median follow-up was 51 months. The 5-year OS rate was 17.7% in arm 1 (95% CI, 6% to 34%) versus 42.3% in arm 2 (95% CI, 28% to 56%; stratified log-rank P = .006). The 5-year PFS rate was not reached in arm 1 (3.2%; 95% CI, 0% to 14% at 4 years with last patient censored) and 17.3% in arm 2 (95% CI, 8% to 30%; P = .001). There were no new grade 2-5 adverse events and no differences in QOL between arms.
Conclusion: With extended follow-up, the impact of SABR on OS was larger in magnitude than in the initial analysis and durable over time. There were no new safety signals, and SABR had no detrimental impact on QOL.
Trial registration: ClinicalTrials.gov NCT01446744.
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Comment in
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SABR for metastasis-directed therapy - what we've learned and what's to come.Nat Rev Clin Oncol. 2020 Oct;17(10):593-594. doi: 10.1038/s41571-020-0416-9. Nat Rev Clin Oncol. 2020. PMID: 32699308 No abstract available.
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[Curative radiotherapy of oligometastatic cancer: long-term results of the SABR-COMET phase II trial].Strahlenther Onkol. 2021 Apr;197(4):365-367. doi: 10.1007/s00066-021-01745-w. Epub 2021 Feb 2. Strahlenther Onkol. 2021. PMID: 33532894 Free PMC article. German. No abstract available.
References
-
- Barney J, Churchill E. Adenocarcinoma of the kidney with metastasis to the lung cured by nephrectomy and lobectomy. J Urol. 1939;42:269–276.
-
- Pastorino U, Buyse M, Friedel G, et al. Long-term results of lung metastasectomy: Prognostic analyses based on 5206 cases. J Thorac Cardiovasc Surg. 1997;113:37–49. - PubMed
-
- Bartlett EK, Simmons KD, Wachtel H, et al. The rise in metastasectomy across cancer types over the past decade. Cancer. 2015;121:747–757. - PubMed
-
- Palma DA, Salama JK, Lo SS, et al. The oligometastatic state—Separating truth from wishful thinking. Nat Rev Clin Oncol. 2014;11:549–557. - PubMed
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