Survival analysis for lung adenosquamous carcinoma patients with brain metastasis

Abstract

Purpose: We retrospectively collected consecutive survival data of lung adenosquamous cell carcinoma (ASC) patients with brain metastasis (BM) in our institute and discussed the factors related to prognosis of these patients. Patients and Methods: A total of 42 patients diagnosed as lung ASC with BM between July 1, 2008 and December 31, 2010 at the Department of Respiratory Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University were retrospectively reviewed. Time to BM (TTB) and overall survival (OS) data were analyzed. OS1 was calculated from the time ASC was diagnosed until the death of a patient. OS2 was defined as the duration from BM was first identified to the death of a patient. 1-year, 2-year and 3-year survival rates were also computed. Univariate and multivariate survival analysis was performed using Kaplan-Meier methods and Cox regression. Results: The median TTB for all patients was 5.7 months [95% confidence interval (CI): 0.8 - 10.6 months]. The median OS1 was 13.8 months (95%CI: 11.2 - 16.4 months). TTB longer than 12 months [adjusted HR: 0.15 (95%CI: 0.05 -0.48 vs. TTB≤ 6 months, P=0.001); 0.22 (95%CI: 0.07- 0.71, vs. TTB 6-12 months, P=0.010) and resection for BM lesions [adjusted hazard ratio (HR): 0.47 (95%CI: 0.24 - 0.94 vs. not resected, P=0.032)] were independent predictors for a longer OS1. The median OS2 was 7.9 months (95%CI: 4.5 - 11.3 months). Treatment cycles more than 3 [adjusted HR: 0.41 (95%CI: 0.20 - 0.83 vs. treatment cycles <3, P=0.013)] was an independent predictor for a longer OS2. Conclusions: This study shows that resection of BM if possible, and standard chemo-radiotherapy in patients with multiple BM lesions is associated with longer overall survival.

Keywords: brain metastasis (BM).; lung adenosquamous carcinoma (ASC); lung cancer; non-small-cell lung cancer (NSCLC); survival.

Figure 1

Survival data for all patients. BM: brain metastasis; TTB: time to brain metastasis; OS1: overall survival 1; OS2: overall survival 2; BM number: S=single; M=multiple. Differentiations: L=low; M=moderate; H=high.

Figure 2

Kaplan-Meier curves for overall survival of primary lung adenosquamous carcinoma patients with brain metastasis. (A) The Kaplan-Meier curvefor OS1 of primary lung adenosquamous carcinoma patients with brain metastasis. The median OS1 was 13.8 months (95%CI: 11.2 - 16.4 months). (B) The Kaplan-Meier curve for OS2of primary lung adenosquamous carcinoma patients with brain metastasis. The median OS2 was 7.9 months (95%CI: 4.5 - 11.3 months). OS1: overall survival 1; OS2: overall survival 2.

Figure 3

Kaplan-Meier curves of factors that independently influence OS1 and OS2. (A) Kaplan-Meier curves for OS1 of patients with TTB longer than 12 months, TTB 6-12 months and TTB ≤ 6 months. TTB longer than 12 months were independent predictors for a longer OS1[adjusted HR: 0.15 (95%CI: 0.05 -0.48 vs. TTB≤ 6 months, P=0.001);0.22 (95%CI: 0.07- 0.71, vs. TTB 6-12 months, P=0.010). (B) Kaplan-Meier curves for OS1 of patients with BM lesions resected and not resected. Resection for BM lesions was an independent predictor for a longer OS2 [adjusted HR: 0.47 (95%CI: 0.24 - 0.94 vs. not resected, P=0.032)]. (C) Kaplan-Meier curves for OS2 of patients with chemotherapy cycles more than 3 and patients with chemotherapy cycle less than 3. Treatment cycles more than 3 was an independent predictor for a longer OS2 [adjusted HR: 0.41 (95%CI: 0.20 - 0.83 vs. treatment cycles <3, P=0.013)].