Risk factors for brain metastases after definitive chemoradiation for locally advanced non-small cell lung cancer

Abstract

As therapy for locally advanced nonsmall cell lung carcinoma (NSCLC) improves, brain metastases (BM) still remain a great problem. The aim of the study was to analyze risk factors for BM in patients with locally advanced NSCLC after chemoradiation therapy. Records for 150 patients with non-resectable stage IIIA/IIIB NSCLC treated with combined chemoradiation therapy were analyzed. All of them had negative brain metastases imaging result before the treatment. Incidence of BM was examined in relation to age, sex, histological type, stage, performance status scale of wellbeing of cancer patients, weight loss, chemotherapy regimen and chemotherapy timing. One- and 2-year incidence rates of BM were 19 and 31%, respectively. Among pretreatment parameters, stage IIIB was associated with a higher risk of BM (p < 0.004) vs. stage IIIA. Histologically, the patients with nonsquamous tumors had an exceptionally high 2-year BM risk rate of 32% (p < 0.02). Examining treatment-related parameters, 1-year and 2-year actuarial risk of BM were 27 and 39%, respectively, in the patients receiving chemotherapy before radiotherapy and 15 and 20%, respectively, when radiotherapy was not delayed (p < 0.03). On multivariate analysis, timing of chemotherapy (p < 0.05) and stage IIIA vs. IIIB (p < 0.01) remained statistically significant. Patients with IIIB stage, nonsquamous NSCLC, particularly those receiving sequential chemotherapy, had significantly high BM rates.