Prevalence, treatment patterns, and survival of patients with brain metastases from small cell lung cancer: A retrospective study using the TriNetX Oncology Database.

Background: Brain metastases (BM) portend increased morbidity and mortality in patients with small cell lung cancer (SCLC). We aimed to characterize the prevalence, timing, treatment patterns, and survival outcomes of BM associated with SCLC over the past decade.

Methods: Data from 4014 patients with histologically confirmed SCLC were extracted from the TriNetX Oncology database. Clinical and demographic variables were compared between patients with and without BM using Chi-squared and t-tests. Kaplan-Meier and Cox regression analyses were used to evaluate overall survival (OS), after propensity score matching cohorts for age at diagnosis, sex, cancer stage at diagnosis, extracranial metastases, and cancer-directed therapy.

Results: Among 4014 patients with SCLC, 35.0% had BM (9.9% synchronous, 21.2% metachronous, 3.9% precocious). Patients who developed BM were younger (P < .001) at SCLC diagnosis, more likely Black/African American (P = .0068), and presented with more advanced cancer stages (P < .001) than patients who did not develop BM. The median BM-free survival from the time of SCLC diagnosis was 27.9 months. Patients with BM received higher rates of cancer-directed therapies than those without BM. Synchronous BM was associated with lower OS than metachronous BM after the diagnosis of SCLC (HR[95% CI] = 1.56[1.32-1.83]), but there was no difference in OS after the BM diagnosis. OS did not differ between patients with BM and patients with extracranial metastases only, following the diagnosis of metastatic disease.

Conclusions: Our findings support that independently of the chronicity of BM diagnosis, patients with SCLC have poor survival once the diagnosis of BM is conferred.