J Cancer 2017; 8(3):455-459. doi:10.7150/jca.17104
Changes in Disease Failure Risk of Nasopharyngeal Carcinoma over Time: Analysis of 749 Patients with Long-Term Follow-Up
1. 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.
2. Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Canton 510060, China.
* Xu Liu, Ling-Long Tang and Xiao-Jing Du contributed equally to this work.
Liu X, Tang LL, Du XJ, Li WF, Chen L, Zhou GQ, Guo R, Liu Q, Sun Y, Ma J. Changes in Disease Failure Risk of Nasopharyngeal Carcinoma over Time: Analysis of 749 Patients with Long-Term Follow-Up. J Cancer 2017; 8(3):455-459. doi:10.7150/jca.17104. Available from http://www.jcancer.org/v08p0455.htm
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.
Keywords: Nasopharyngeal neoplasms, Prognosis, Recurrence, Mortality, Hazard function.