Survival and prognostic factors in non-small cell lung cancer patients with brain metastases limited access to systemic therapy

Abstract

Background Survival after diagnosis of brain metastases in non-small cell lung cancer (NSCLC) patients was dismal even after local therapy (surgery or brain irradiation), partly because of the systemic burden. Paucities of medical oncologists and molecular testing plus disparities in health care coverage resulted in limited access to systemic chemotherapy, let alone targeted drug or immunotherapy, for brain metastatic non-small cell lung cancer (BM-NSCLC) in Thailand. In this study, we aimed to explore prognostic factors affecting overall survival and evaluate survival outcome in BM-NSCLC limited access to systemic therapy. Methods We retrospectively collected 83 BM-NSCLC from a tertiary care hospital in Thailand. Data regarding clinical characteristics and treatment factors including age, sex, performance status, histology, neurologic symptom, extra-cranial metastasis (ECM), receiving whole brain radiotherapy (WBRT) and receiving systemic treatment were collected as independent factors. Associations between these variables and time to death were analyzed using the Cox proportional hazard regression. Results The patients' mean age was 63.1 year (SD 8.9). Most of the patients had adenocarcinoma (73%), presented with major neurological symptom (84%), and had brain metastases at their initial diagnosis of lung cancer (65%). Nearly 30% had ECM while 14% received systemic treatment. Three-quarters of patients received WBRT. Less than 15% were tested for actionable mutations. The median survival time was 2.7 months (95%CI: 2.2–4.1 months). One-month, three-month, six-month, and one-year survival probability was 78.3% (95%CI: 52.6–73.2%), 47.0% (95%CI: 36.0-57.2%), 26.5% (95%CI: 17.6–36.3%), and 9.6% (95%CI: 4.5–17.1%), respectively. Multivariable analysis showed that having extra-cranial disease was significantly associated with death (HR 4.22, 95%CI:1.27-14.0,p = 0.019 for first diagnosis lung with any ECM; HR 6.33, 95%CI:1.62–24.79, p = 0.008 for controlled lung & ECM; and HR 11.32, 95%CI:2.89–56.1, p = 0.003 for uncontrolled lung or ECM). Receiving systemic treatment was significantly associated with a reduced risk of death (HR0.39, 95%CI:0.18–0.80, p = 0.011). WBRT was insignificantly associated with prolonged survival (HR 0.79, 95%CI:0.43–1.44, p = 0.441). Conclusion Extracranial disease and lack of systemic treatment significantly shortened survival in BM-NSCLC.