No Survival Advantage With Whole-Brain RT vs Stereotactic Radiosurgery for SCLC
In evaluating the outcomes of stereotactic radiosurgery (SRS) versus whole-brain radiotherapy (WBRT) for small-cell lung cancer (SCLC), researchers found no overall advantage in survival between the 2, but did observe a superior time to central nervous system (CNS) progression (TTCP) with WBRT (JAMA Oncol. 2020;6[7]:1028-1037).
“Although [SRS] is preferred for limited brain metastases from most histologies, [WBRT] has remained the standard of care for patients with small cell lung cancer. Data on SRS are limited,” wrote Chad Rusthoven, MD, Aurora, Colorado, and colleagues.
Dr Rusthoven et al analyzed the overall survival (OS), TTCP, and CNS progression free survival (PFS) in a total of 710 patients (median age, 68.5 years) with SCLC brain metastases who received SRS between 1994 and 2018.
When stratified by the number of brain metastases treated, patients with 1 lesion had a median OS of 11.0 months (95% CI, 8.9-13.4), for 2 to 4 lesions the median was 8.7 months (95% CI, 7.7-10.4), 5 to 10 lesions the median was 8.0 months (95% CI, 6.4-9.6), and for ≥11 lesions the median was 5.5 months (95% CI, 4.3-7.6).
Furthermore, the durations of median OS, TTCP, and CNS PFS were 8.5, 8.1, and 5.0 months, respectively.
According to the researchers, these findings revealed that propensity score–matched analyses comparing SRS with WBRT associated WBRT with improved TTCP (hazard ratio, 0.38; 95% CI, 0.26-0.55; P <.001).
However, there was no improvement in OS (median: SRS, 6.5 months; 95% CI, 5.5-8.0 vs WBRT, 5.2 months; 95% CI, 4.4-6.7; P = .003) or CNS PFS (median: SRS, 4.0 months vs WBRT, 3.8 months; P = .79).
Multivariable analyses comparing the 2 yielded similar results.
“Results of this study suggest that the primary trade-offs associated with SRS without WBRT, including a shorter TTCP without a decrease in overall survival, are similar to those observed in settings in which SRS is already established,” concluded Dr Rusthoven et al.—Alexandra Graziano
