Anemia is a Significant Prognostic Factor in Overall Survival of Patients with Non-Small Cell Lung Cancer Treated with Stereotactic Body Radiation Therapy

Abstract

Anemia has been associated with poor prognosis in patients with several types of cancer. The purpose of this study was to determine whether there is an association between the pre-treatment anemia and prognosis of patients with lung cancer treated with stereotactic body radiation therapy (SBRT). The inclusion criteria were as follows: patients with localized non-small-cell lung cancer (NSCLC), with N0M0 disease, who were medically inoperable or refused to undergo surgery, were treated with SBRT, and for whom hemoglobin levels were available within 2 weeks prior to SBRT. In total, 77 patients met these criteria. Univariate and multivariate Cox proportional hazard regression models were used to estimate overall survival (OS) rates. Variables of which the p-values were <0.20 were included in the multivariate analysis. Receiver-operating characteristic analysis was performed to determine the optimal cut-off values for the hemoglobin. The median age of the 77 participants (56 male, 21 female) was 80 (range, 50-90) years. Most of the patients presented with performance status 0 or 1 (n = 71, 92.2%). The median body mass index was 21.5 (range, 13.1-37.3) kg/m2. The median diameter of the tumor was 19 (range, 7-40) mm. More than half of the patients had a smoking history (n = 57, 74.0%). The number of patients with pathological confirmation of lung cancer was 35 (45.4%). The remaining patients were diagnosed based on the observation of increasing size and abnormal uptake on PET. The numbers of patients with comorbidities of diabetes was 17 (22.1%). The reasons for choosing SBRT were medical inoperability (n = 56, 72.7%) and refusal of surgery (n = 21, 27.3%). In principle, the prescribed dose to peripheral tumors was 50 Gy in 5 fractions (n = 50, 64.9%) until September 2016 and 48 Gy in 4 fractions (n = 23, 29.9%) after October 2016. The tumors with central lesions located near organs at risk were treated with 60 Gy in 8 fractions (n = 3, 3.9%). The median hemoglobin level was 128 (range, 78-183) g/L. The optimal cut-off values for the OS rates were 116 g/L. Univariate Cox proportional hazards regression analysis determined the anemia as a significant factor for OS rates. Multivariate analysis also determined the anemia as a significant factor (p = 0.02469). Our data suggest that anemia is correlated with OS rates in patients with early-stage NSCLC treated with SBRT.Abstract 2339; TableThe results of univariate and multivariate analysis in overall survival rate.VariablesUnivariateMultivariateHazard ratiop valueHazard ratiop valueAge (years) (continuous)1.0290.3744Performance status (≥1 vs. 0)1.3360.5689Smoking history (yes vs. no)0.48230.2231Diabetes mellitus (yes vs. no)1.180.7744Operability (yes vs. no)0.88230.8286Pathology (confirmed vs. unknown)0.41770.082240.62070.36400Tumor diameter (mm) (continuous)1.02700.3913Hb (g/L) (<116 vs. ≥116)3.8090.0072383.26700.02469 Open table in a new tab