Brain metastases and non-small cell lung cancer. Prognostic factors and correlation with survival after irradiation

A total of 250 patients with brain metastases from non-small cell lung cancer (NSCLC) were treated with irradiation of their brain metastases. The median overall survival was 3.1 (95% CI: 2.7-3.5) months. 32/250 patients presenting with solitary brain metastasis underwent surgical resection. Their 1-year survival rate of 58% was significantly better than 89/250 patients with a solitary lesion but without surgery (14%, P=0.001). Patients with an absent or controlled primary tumor (101/250, 40.5%) had a 1-year survival rate of 26% as opposed to 11% for patients presenting with an active primary tumor (P=0.051). Patients presenting with metastases to the brain only showed a significant survival advantage over patients with extracranial metastases (1-year survival of 21% vs 6%, P=0.001). Karnofsky performance score, neurofunction status and response to steroids were also identified as prognostic factors. The total dose whole brain irradiation (WBI) was prognostic of significance with a 1-year survival of 35% for 30 Gy and boost, 23.5% for 30 Gy and 4% for the patients irradiated to a dose of 20 Gy WBI (P=0.001). When patients were grouped into the RTOG RPA (Recursive partitioning analysis) classes, patients within class I (73/250) had a 1-year survival of 28.5%, patients in class II (145/250) a survival of 14% at 1 year and patients into class III only a 6% 1-year survival rate. In a multivariate analysis, surgical resection, neurofunction class, metastatic extent and WBI dose remained significant prognostic factors. Although survival remains poor, there needs to be a continued interest in these patients, probably by participating in clinical trials.