title: Changes in Disease Failure Risk of Nasopharyngeal Carcinoma over Time: Analysis of 749 Patients with Long-Term Follow-Up.
abstract: Background:The changes in the risk of disease failure over time in nasopharyngeal carcinoma (NPC) remains unknown.Methods:We analyzed 749 patients treated with intensity-modulated radiotherapy in a single center. The annual hazard rates of disease failure (recurrence or death from any cause) were estimated using the life-table method.Results:In total, 41 (5.5%), 22 (2.9%) and 129 (17.2%) patients developed local, regional and distant recurrences, respectively; 149 (19.9%) patients died. Of the 600 patients who were alive at the last follow-up, 496 (82.7%) had follow-up times longer than 6 years. The 6-year failure-free survival rate was 74.8%. Older age (> 50 years) and advanced stage (Ⅲ-ⅣB) were independent risk factors for disease failure in multivariate analysis. The hazard curve for failure risk in the whole cohort showed a sharp peak at 2 years, changed to a gradually decreasing plateau between years 3 and 5 and then declined sharply. Subgroup analyses revealed similar hazard curves in both sexes. However, the patterns of hazard curve significantly differed between high-risk (> 50 years or stage Ⅲ-ⅣB) and low-risk (≤ 50 years or stage Ⅰ-Ⅱ) patients.Interpretation:The failure hazard rate in NPC didn't decline in a linear manner, but displayed a sharp peak at 2 years. The patterns of hazard function significantly differed between patients with different age and stage. Further studies are warranted to confirm our results.
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton 510060, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton 510060, China.
authors.forename: Ling-Long
authors.initials: LL
authors.lastname: Tang
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton 510060, China.
authors.forename: Xiao-Jing
authors.initials: XJ
authors.lastname: Du
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton 510060, China.
authors.forename: Wen-Fei
authors.initials: WF
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton 510060, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton 510060, China.
authors.forename: Guan-Qun
authors.initials: GQ
authors.lastname: Zhou
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton 510060, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Guo
authors.affiliation: Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Canton 510060, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton 510060, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Canton 510060, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
keywords: Hazard function.; Mortality; Nasopharyngeal neoplasms; Prognosis; Recurrence