Apolipoprotein A-I Is a Prognosticator of Nasopharyngeal Carcinoma in the Era of Intensity-modulated Radiotherapy

Background: In the era of intensity-modulated radiotherapy (IMRT), distant metastasis remains the major cause of death from nasopharyngeal carcinoma (NPC). This study aimed to evaluate the clinical value of pretreatment serum lipid profiles in predicting clinical outcome of NPC. Methodology / Principal Findings: A total of 1927 consecutive patients who had untreated NPC and completed radical IMRT between Jan. 2010 and Dec. 2011 were retrospectively reviewed. Pretreatment serum lipid indexes including total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein A-I (apoAI) and apolipoprotein B were analyzed for their association with survivals, together with the clinical features (age, sex, pathological type, anemia, chemotherapy sequence and Epstein-Barr virus deoxyribonucleic acid). Hazard ratio (HR) and 95% confidence interval (CI) were calculated for each independent prognosticator. After univariate and multivariate survival analysis, low apoAI level (< 1.125 mmol/L) appeared to predict poor 5-year overall survival (OS), disease-free survival (DFS) and distant-metastasis-free survival (DMFS). The HRs were 1.549 (95% CI, 1.137-2.109), 1.293 (95% CI, 1.047-1.597) and 1.288 (95% CI, 1.022-1.623), respectively. Subgroup survival analysis showed that the apoAI maintained predicting independence for OS, DFS and DMFS in patients with locally advanced NPC, even in those treated with concurrent chemoradiotherapy. Conclusions / Significance: NPC patient with low serum level of pretreatment apoAI might be at risk of distant metastasis. Treatment aiming to eradicate distant metastasis might improve survival of these patients.