Response of Asymptomatic Brain Metastases From Small-Cell Lung Cancer to Systemic First-Line Chemotherapy

Abstract

The purpose of this study was to investigate the radiologic response of asymptomatic brain metastases (BM) from small-cell lung cancer (SCLC) to first-line systemic chemotherapy. From 1990 to 2003, 181 consecutive patients with SCLC were enrolled onto this study. Patients were examined by a neurologist on a regular basis. Magnetic resonance imaging (MRI) of the brain was performed routinely before (at diagnosis of SCLC) and after first-line systemic chemotherapy. Patients were treated with combination chemotherapy consisting of cyclophosphamide, doxorubicin, and etoposide. Clinically manifest BM were treated with whole-brain radiotherapy (WBRT). The response rate (RR) of BM was assessed by changes in the size or the number of enhanced lesions on MRI using standard criteria. Synchronous asymptomatic BM were found in 24 SCLC patients (13%). In six (27%) of the 22 assessable patients, the asymptomatic BM responded to systemic chemotherapy. A systemic response was found in 16 patients (73%). All patients became symptomatic during follow-up. The symptom-free survival did not differ between cranial responders and cranial nonresponders. The RR of asymptomatic BM from SCLC to systemic chemotherapy is 27% and evidently lower than the systemic RR. Future studies should focus on the possible beneficial effect of WBRT for patients with asymptomatic synchronous BM.