J Cancer 2018; 9(18):3352-3360. doi:10.7150/jca.25530

Research Paper

Surrogate endpoints shortening the therapeutic evaluation duration for different subgroups of patients with nasopharyngeal carcinoma receiving intensity-modulated radiotherapy: A retrospective analysis of 830 patients stratified by the 8th edition of the UICC/AJCC staging system and plasma Epstein-Barr viral

Shu Zhou1,2*, Chen Chen 1,2*, Song-ran Liu1,2, Ya-lan Tao 1,2, Hui Chang1,2, Xiao-hui Wang1,2, Xin Yang1,2, Wen-wen Zhang1,2, Shan Liu 1,2, Shi-rong Ding1,2, Guan-nan Wang1,2, Yun-fei Xia1,2✉

1. State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, Guangdong, P. R. China.
2. Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou 510060, Guangdong, P. R. China.
*These authors contributed equally to this work.

Abstract

Purpose: Investigating surrogate endpoints shortening the time of therapeutic evaluation in nasopharyngeal carcinoma (NPC) after radical treatment.

Patients and Methods: We retrospectively analyzed 830 patients receiving intensity-modulated radiotherapy (IMRT) from 2008 to 2010 and being stratified by the 8th edition of UICC/AJCC staging system and the plasma Epstein-Barr virus DNA (EBV DNA). The annual rates of overall survival (OS), progression-free survival (PFS), loco-regional recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were sequentially calculated using the life table and compared by the McNemar method.

Results: The time of shortening therapeutic evaluation by surrogate endpoints: OS, PFS, LRFS and DMFS could be shortened to 1-year (100% vs 100%, P=1) in patients with stage I; OS, PFS, LRFS and DMFS could be shortened to 3-year (96.9% vs 96.1%, P = 1; 94.6% vs 92.2%, P = 0.125; 96.9% vs 95.3%, P = 0.5) and 4-year (92.2% vs 91.2%, P = 0.125) in stage II; In the high EBV DNA group , OS and DMFS could be shortened to 1-year (100% vs 100%, P = 1;100% vs 100%, P = 0.25) in stage II; OS and PFS could be shortened to 3-year (94.3% vs 91.4%, P = 1;82.9% vs 74.3%, P = 0.25) in stage III; OS could be shortened to 4-year (75% vs 72.7%, P = 1) in stage IVA.

Conclusions: The time of therapeutic evaluation could be shortened to <5-year in stages I-II patients. The year of surrogate endpoints could be ahead in stages II-IVA with high EBV DNA.

Keywords: nasopharyngeal carcinoma, surrogate endpoints, intensity-modulated radiotherapy, the 8th edition of UICC/AJCC staging, Epstein-Barr Viral DNA, overall survival, progression-free survival, loco-regional recurrence-free survival, distant metastasis-free survival

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How to cite this article:
Zhou S, Chen C, Liu Sr, Tao Yl, Chang H, Wang Xh, Yang X, Zhang Ww, Liu S, Ding Sr, Wang Gn, Xia Yf. Surrogate endpoints shortening the therapeutic evaluation duration for different subgroups of patients with nasopharyngeal carcinoma receiving intensity-modulated radiotherapy: A retrospective analysis of 830 patients stratified by the 8th edition of the UICC/AJCC staging system and plasma Epstein-Barr viral. J Cancer 2018; 9(18):3352-3360. doi:10.7150/jca.25530. Available from http://www.jcancer.org/v09p3352.htm