Patterns Of Care In The Non-Operative Management Of Elderly Patients With NSCLC Brain Metastases

Abstract

Many patients diagnosed with advanced non-small cell lung cancer (NSCLC) will develop intracranial metastasis contributing significantly to oncologic morbidity and mortality. Radiotherapeutic options include stereotactic radiosurgery (SRS) and whole brain radiotherapy (WBRT). Elderly patients generally tolerate whole brain radiotherapy (WBRT) poorly with questionable survival benefit. As such, we queried the National Cancer Database (NCDB) to: examine trends in the non-operative management of patients with NSCLC related brain metastasis, identify predictors of treatment modality receipt, and compare survival outcomes based upon treatment. We queried the NCDB for elderly metastatic NSCLC patients (age ≥ 70) with brain metastasis receiving either systemic therapy alone or systemic therapy plus intracranial radiation [including stereotactic radiosurgery (SRS) or whole brain radiation therapy (WBRT)]. Univariable and multivariable analyses were used to identify characteristics predictive of overall survival. Kaplan Meier method was used to compare overall survival among the three treatment arms (Arm 1: No intracranial radiation, Arm 2: WBRT, Arm 3: SRS). Multivariable logistic regression was used to identify predictors of SRS receipt. A total of 3,150 NSCLC patients with brain metastasis who received systemic therapy alone (19%) or systemic therapy plus intracranial radiation [WBRT (55%), or SRS (26%)] were eligible for analysis. Univariable analysis demonstrated a median overall survival of 8.6 months (95% CI: 7.8-9.7), 6.8 months (95% CI: 6.5-7.2), and 10.9 months (95% CI: 10.1-11.9) for patients receiving systemic treatment alone, WBRT, and SRS respectively. Survival rates at 1 year and 3 years were 38%, 29%, 46% and 11%, 5%, and 13% for patients receiving systemic treatment alone, WBRT, and SRS respectively. Squamous histology, age > 74, worse co-morbidity scores, and presence of liver metastasis were associated with worse overall survival (OS), whereas receipt of SRS, more recent treatment year, female sex, and treatment at an academic facility were associated with improved OS (p<0.01 for all). The presence of bone or liver metastasis were associated with a lower likelihood of SRS receipt, while more recent treatment year, treatment at an academic facility, and higher patient income were associated with a higher likelihood of SRS. SRS utilization increased over time from 22% in 2010 to 31% in 2014. Targeted/immunotherapy was used in only 3% of patients overall. Utilization of SRS in elderly patients with NSCLC related brain metastasis increased over time, while WBRT utilization rates decreased. SRS use was associated with lower metastatic disease burden, which may confound interpretation of the apparent survival benefit reflected in our study.