KEY POINTS
- The National Cancer Database analysis included 631 patients with clinical T1–2N0M0 small cell lung cancer treated without surgery using both SBRT and chemotherapy between 2004 and 2020.
- SBRT was delivered in 1–5 fractions with a biologically effective dose of 100–180 Gy. Of the cohort, 416 patients (65.9%) received SBRT before chemotherapy and 215 (34.1%) started SBRT concurrently with or after chemotherapy.
- Median overall survival was 40.5 months with SBRT first versus 35.6 months when SBRT began concurrently with or after chemotherapy, with no statistically significant difference (p=0.30).
- After adjustment for patient and treatment characteristics, sequencing remained unrelated to survival (HR 1.11, 95% CI 0.89–1.37, p=0.35).
- A sensitivity analysis excluding 409 patients whose SBRT and chemotherapy started within 30 days of one another again found no survival association (HR 0.94, p=0.73).
- The result was also consistent across clinical T stage: sequencing was not associated with survival in either T1 disease (HR 1.13, p=0.30) or T2 disease (HR 0.72, p=0.36).
- SBRT-first treatment became increasingly common over time. Patients diagnosed in 2019–2020 were 54% less likely to start SBRT concurrently with or after chemotherapy than those diagnosed earlier.
CLINICAL TAKEAWAY
For medically inoperable stage I SCLC, these data suggest that starting chemotherapy before SBRT may not necessarily compromise overall survival if the lung lesion remains suitable for stereotactic treatment. This does not overturn current sequencing recommendations: the analysis is retrospective and lacks local control, distant failure, toxicity, chemotherapy-cycle and modern immunotherapy data.