Based On The Validation Of The 8^TH Edition Of The UICC/AJCC Staging System Evaluate The Treament Outcome For Nasopharyngeal Carcinoma From The South-west Chinaareas In The Era Of Intensity-modulated Radiotherapy

Purpose/Objective(s): Evaluate treament outcome,prognostic,failure patterns in patients with nasopharyngeal carcinoma(NPC)who were treated with intensity-modulated radiotherapy(IMRT)from south-west china areas(Western China)based on the new edition of staging system for NPC.Materials/Methods: Between January 2008 and December 2013,a total of 1078 patients with newly diagnosed,non-metastatic NPC treated with IMRT in Sichuan Cancer Hospital were included.Overall survival(OS),progression-free survival(PFS),Local-Regional failure free survival(LRFFS),Local failure free survival(LFFS),Regional failure free survival(RFFS),Distant failure free survival,(DFFS)were calculated with the Kaplan-Meier method,and differences were compared by using the log-rank test.Akaike information criterion(AIC)and Harrell’s concordance index(c-index)were calculated to compare the performance of various staging systems.We analyzed the risk consistency and prognostic factors.Results: The median age was 46 years(range,12-84 years)with a male-to-female ratio of 2.37 to1(756:322).The median follow-up time was 51months(range,3-120months).The 5-year OS,PFS,LRFFS,LFFS,RFFS and DFFSrates for the whole group were 82.4%、77.0%、90.1%、92.1%、97.4%、83.8%,Over 90% of the patients had loco-regional advanced(III+IVa)diseases according to both editions.respectively.Older age,advanceed T and N stage were adverse prognostic factors for 5-yeas OS,PFS and DFFS.Male gender and smoking were adverse prognostic factors for 5-yeas LRFFS.Whereas use of chemotherapy in form of conrrent chemo-irradiation(CRT),neoadjuvant + CRT were favorable progositc factor for 5-years DFFS.Distant metastasis was the commonest site of failureBased on the 8th edition,the OS and PFS curves of different T categories were better separated than 7th edition,except the T2 and T3 categories.The 8th edition had better AIC and c-index values for OS and PFS than the 7th edition.While,for LRFFS,the curves cannot be well separated according to both editions.For N category,the survival curves of different groups according to the8 th edtion were well-separated.Conclusion:(1)IMRT is an effctive radiation treament for NPC from non-endemic areas.(2)Distant metastasis also remains the major pattern of failure.(3)The 8th edition of the UICC/AJCC staging system may not be able to well predict the treatment outcomes for NPC patients from south-west china areas like Western China.More validation studies from non-endemic areas are needed.