Response of asymptomatic brain metastases from small-cell lung cancer to systemic first-line chemotherapy.

PURPOSE: 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. PATIENTS AND METHODS: 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.
RESULTS: 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.
CONCLUSION: 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.