358P - Intracranial metastatic disease (IMD) burden and management of patients with small cell lung cancer (SCLC): A population-based analysis of 8705 patients

Background

Patients with SCLC have historically been characterised by poor overall survival (OS) and high risk for IMD, but large-scale real-world evidence on clinical presentation and treatment in this population is lacking. These patients traditionally receive whole brain radiation therapy (WBRT) for IMD, however, a recent systematic review has indicated that OS following stereotactic radiosurgery (SRS) may be non-inferior compared with WBRT. We aim to describe the clinical characteristics and outcomes of patients with SCLC and IMD in Ontario, Canada.

Methods

We included all patients diagnosed with SCLC between April 2007 and March 2018 identified through a provincial health administrative database. Information on patient and treatment characteristics, incidence and time to IMD, and OS from time of SCLC diagnosis were collected and analyzed using R.

Results

A total of 8705 patients were included. Median age was 68 years (range 18-103). Most patients presented with extensive disease (n=5625) and were diagnosed after 2011 (n=5768). Patients who received chemotherapy (n=5563) had significantly longer OS than those who did not (median 10.64 vs 1.58 months (mo), hazard ratio (HR) 0.36, 95% confidence interval (CI) 0.34-0.37). 6662 patients received brain imaging at the time of primary diagnosis (CT: 5126, MRI: 1536), and 88% of patients surviving longer than 6 mo received more than one follow-up brain scan. 31% developed IMD (synchronous: 1175, asynchronous: 1511) with median intracranial progression-free survival of 5.65 mo. Median OS of patients with IMD was 9.76 mo, 29 and 1300 received SRS and WBRT as first treatment for their IMD, respectively. OS was in favour of SRS over WBRT (median 20.47 vs 8.74 mo, HR 0.57, 95% CI 0.39-0.84), which remained significant in multivariate analysis (p<0.001).

Conclusions

OS for patients with SCLC remains poor, and many patients present with IMD. With careful selection, patients with SCLC may benefit from SRS treatment.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

B. Lok: Financial Interests, Personal, Other, Honoraria: AstraZeneca; Financial Interests, Institutional, Funding: Pfizer, AstraZeneca; Financial Interests, Personal, Officer, Accommodations, travel expenses: AstraZeneca. S. Das: Financial Interests, Institutional, Research Grant: Canadian Institute for Health Research, Alkemes; Financial Interests, Institutional, Funding: Gratitude 10; Financial Interests, Personal, Royalties: Oxford University Press; Financial Interests, Personal, Invited Speaker: Medexus; Financial Interests, Personal, Other, travel, accommodation: Congress of Neurological Surgeons, American Association of Neuorlogical Surgeons; Non-Financial Interests, Personal, Advisory Board: Subcortical Surgery Group, XPan Medical; Non-Financial Interests, Personal, Speaker’s Bureau: Congress of Neurological Surgeons, American Association of Neurological Surgeons, Society for NeuroOncology; Non-Financial Interests, Personal, Principal Investigator: Agios. All other authors have declared no conflicts of interest.