Prognostic value of pretreatment body mass index in patients with unresectable locally advanced non-small cell lung cancer after chemoradiotherapy / 肿瘤研究与临床

ABSTRACT

Objective:To explore the effect of pretreatment body mass index (BMI) on the prognosis of patients with unresectable locally advanced non-small cell lung cancer (NSCLC) after chemoradiotherapy.Methods:The clinical data of 711 patients with locally advanced NSCLC treated with radiotherapy, sequential chemoradiotherapy or concurrent chemoradiotherapy from January 2013 to December 2017 in Cancer Hospital of Chinese Academy of Medical Science and Peking Union Medical College were retrospectively analyzed. Radiotherapy was performed with intensity-modulated radiotherapy (IMRT) or volumetric-modulated arc therapy (VMAT), and the chemotherapy regimens were paclitaxel+carboplatin, pemetrexed+cisplatin or etoposide+cisplatin. The effects of pretreatment BMI and other clinical factors on overall survival (OS) of patients were analyzed. Survival analysis was performed by using Kaplan-Meier method; univariate and multivariate analyses were performed by using Cox proportional hazards model.Results:According to the World Health Organization (WHO) recommended BMI grouping method for Asian, the median OS time of low BMI group (<18.5 kg/m 2, 23 cases), normal BMI group (18.5-23.9 kg/m 2, 293 cases) and high BMI group (≥24.0 kg/m 2, 395 cases) was 17 months (95% CI 11-29 months), 29 months (95% CI 22-36 months) and 30 months (95% CI 27-34 months), respectively. OS in the low BMI group was poorer than that in the normal BMI group and high BMI group ( χ2 = 11.20, P = 0.004). Maximally selected rank statistics was used to determine the optimal cut-off value of BMI for prediction of survival as 21.31 kg/m 2, according to which patients were divided into low BMI group (BMI<21.31 kg/m 2, 130 cases) and high BMI group (BMI≥21.31 kg/m 2, 581 cases), the median OS time of the two groups was 20 months (95% CI 17-27 months) and 32 months (95% CI 28-35 months), respectively. OS in the low BMI group was poorer than that in the high BMI group ( χ2 = 12.30, P < 0.001). Multivariate analysis showed that age ≥ 65 years old, male, Karnofsky score < 80 points, low BMI, smoking, histological type of squamous cell carcinoma and radiotherapy alone were independent risk factors for OS (all P < 0.05). Conclusions:For patients with unresectable locally advanced NSCLC who received chemoradiotherapy, those with low pretreatment BMI have poor prognosis.