Stereotactic Radiation (SABR) for the Comprehensive Treatment of Oligometastases (SABR-COMET): Extended Long-Term Outcomes
by Stephen Harrow et al (LANCET May 2022)
Randomized phase II trial.
99 patients with a controlled primary tumor and 1 to 5 metastases, with all metastases amenable to SABR
-palliative standard-of-care treatment (control arm) vs. SABR to all metastases + standard of care (SABR arm)
-primary tumor sites included lung, breast, colon, prostate and other
- Eight-year OS was 27.2% in the SABR arm versus 13.6% in the control arm (p = .008).
- Eight-year PFS estimates were 21.3% versus 0.0%, respectively (p < .001).
- Rates of grade ≥ 2 acute or late toxic effects were 30.3% versus 9.1% (P = .019), with no new grade 3 to 5 toxic effects.
- No differences in quality of life scores between arms.
- Patients in the SABR arm were less likely to require cytotoxic chemotherapy (33.3% vs 54.6%, respectively, P = .043).
Conclusions: SABR achieved durable improvements in OS and PFS, with no new major toxicity signals with extended follow-up. A minority of patients randomized to the SABR arm (21.3%) achieved > 5 years of survival without recurrence.