In a Chinese retrospective cohort study reported in the Journal of Clinical Oncology, Lu et al found that adding brain radiotherapy to continued original systemic therapy produced better outcomes compared to brain radiotherapy and substitution of systemic therapy or substitution of systemic therapy alone in patients with extensive-stage small cell lung cancer (SCLC) with brain-only progression after first-line treatment.
Study Details
The study included 203 patients with brain-only progression from three centers in China who received one of three second-line strategies: continuation of original systemic therapy plus brain radiotherapy (OTP-BRT, n = 71); substitution systemic therapy plus brain radiotherapy (ST-BRT, n = 64); or substitution of systemic therapy alone (ST-alone; n = 68). Inverse probability of treatment weighting was used to balance baseline characteristics. The primary endpoint was overall survival from initiation of second-line treatment (overall survival-2).
Key Findings
In the weighted analysis, median overall survival-2 was 14.7 months in the OPT-BRT group vs 10.2 months in the ST-alone group (hazard ratio [HR] vs OPT-BRT = 1.68, P = .028), and 9.8 months in the ST-BRT group (HR vs OPT-BRT = 1.67, P = .023).
Median progression-free survival-2 was 8.0 months in the OTP-BRT group vs 5 months in the ST-BRT group (P = .179 vs OTP-BRT) and 4.0 months in the ST group (P = .024 vs OTP-BRT).
On multivariable analysis, OTP-BRT was an independent prognostic factor for improved overall survival. The benefit was greatest among patients with prior immunotherapy and longer initial progression-free survival (≥ 7.5 months).
No significant differences in overall survival were observed among radiotherapy modalities (whole-brain radiotherapy vs stereotactic radiosurgery).
The investigators concluded: “For extensive-stage SCLC patients with brain-only progression, continuing the original systemic regimen plus brain radiotherapy yields superior survival compared with switching systemic therapy. This supports a site-of-progression–directed strategy, effectively controlling the CNS sanctuary while maintaining an effective systemic backbone.”
Hui Zhu, MD, of Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China, is the corresponding author for the Journal of Clinical Oncology article.
DISCLOSURE: The study was supported by the National Natural Science Foundation of China and others. For full disclosures of the study authors, visit ascopubs.org.
