Prognostic Value Of Combing Gross Tumor Volume With Body Mass Index In Advaned Nasopharyngeal Carcinoma Patients

Purpose:To assess the prognostic effect of combining gross tumor volume(GTV)with body mass index(BMI)in advanced nasopharyngeal carcinoma(NPC)patients treated with concurrent chemo-radiotherapy.Materials and Methods:210 patients with NPC in UICC stage III–IVa were enrolled retrospectively analyzed.The effects of GTV and BMI on 5-year overall survival(OS),disease free survival(DFS),distant metastasis-free survival(DMFS),and local recurrence-free survival(LRFS),either alone or in combination,were compared.Results:104.41cm3and 22.5kg/m~2 were determined as cut-off values for GTV and BMI respectively.The 5-year OS,DFS,DMFS,and LRFS rates were significantly different between the groups with GTV>104.41cm3and those with GTV?104.41cm3.The groups with BMI>22.5kg/m~2 and BMI?22.5kg/m~2 had significantly different 5-year OS,but were similar in terms of DFS,DMFS,and LRFS.Based on the combination of GTV with BMI,the patients were classified into high-risk,intermediate-risk and low-risk subgroups,and their respective5-year OS were 60.9%,85.9%and 94.5%(P<0.001),DFS were 60.9%,84.8%and 93.0%(P<0.001),DMFS were 66.9%,89.6%and 96.5%(P<0.001),and LRFS were 84.5%,92.1%and 96.5%(P=0.026).Multivariate analysis revealed that the combination of GTV with BMI was ascertained as independent prognostic factor in terms of OS(P=0.001),and only the high-risk group had increased risk in terms of DFS(P=0.001),and DMFS(P=0.003).Conclusion:1.The combination of GTV with BMI has a predictive value in patients with advanced NPC,can improve the accuracy of prognostic assessment compared to individual factors,and provides a theoretical basis for layered treatment and nutritional intervention.2.UICC stage is an independent prognostic factor for OS,DFS,and DMFS,but not an independent prognostic factor for LRFS.Age and T classification were independent prognostic factors of OS.