Survival outcomes after whole brain radiotherapy for brain metastases in older adults with newly diagnosed metastatic small cell carcinoma: A national cancer database (NCDB) analysis.

Abstract

Small cell lung cancer (SCLC) is an aggressive malignancy with a tendency to affect older adults and also metastasize to the brain. Older adults tolerate whole brain radiotherapy (WBRT) poorly with marginal survival benefit. We utilized the national cancer database (NCDB) to evaluate the survival outcomes following WBRT in older adults with SCLC and brain metastases. We identified 1615 patients ≥75 years old diagnosed with SCLC and brain metastases. Patients were categorized by type of therapy: chemotherapy + WBRT (n = 576), chemotherapy alone (n = 238), WBRT alone (n = 360) and no chemotherapy or WBRT (n = 441). Clinical and demographic characteristics were reported for each treatment cohort with a subsequent multivariable regression analysis for survival. Median patient age was 79 years. WBRT median dose was 30 Gy. At time of analysis, 1530 of the cohort had died, yielding a median OS of 2.9 months and 6 month survival of 31% for patients that received chemotherapy. For patients treated without chemotherapy, median OS with WBRT was 1.9 months compared to 1.2 months without (p < .0001). For patients receiving chemotherapy with, and without WBRT, median OS was 5.6 months and 6.4 months, respectively (p = .43). Multivariable cox regression revealed age > 80, extracranial disease, male sex, and rural location as predictors of increased risk of death. In older adult patients with SCLC brain metastasis, WBRT was associated with a modest increase in survival in patients not fit for chemotherapy, and there was no association with increased survival over chemotherapy alone.