Number of metastatic sites is a strong predictor of survival in patients with nonsmall cell lung cancer with or without brain metastases

Abstract

Background: The staging system for non-small cell lung cancer (NSCLC) does not consider tumor burden or number of metastatic sites, although oligometastases are more favorable.

Methods: Using log-rank testing, the authors analyzed overall survival (OS) in 1284 patients newly presenting with metastatic NSCLC by number of metastatic organ sites and the presence of brain metastases.

Results: OS for patients without brain metastases was found to be correlated with the number of metastatic sites (P = .0009). Brain metastases conferred an inferior OS (median of 7 months vs 9 months; 95% confidence interval, 7-8 months vs 8-10 months [P = .00,002]). To evaluate the influence of tumor burden on OS, the authors considered subsets of patients in whom the brain (n = 135) or lung (n = 137) was the solitary metastatic organ site. In patients with brain metastases, OS was found to be correlated inversely with the volume of all metastases or the largest lesion (hazards ratio, 1.04 or 1.03, respectively; P = .01). For patients with lung metastases, OS was better for those with a maximum tumor size below the median of 40 mm (P = .0004).

Conclusions: Staging of NSCLC and clinical trial patient stratification should include quantitation of tumor burden. The prognostic impact of brain metastases is small and partly dependent on tumor volume, which indicates the need for aggressive therapy for patients with NSCLC brain metastasis and their inclusion in clinical trials.