The impact of time factors on overall survival in patients with nasopharyngeal carcinoma: a population-based study.
BACKGROUND
Nasopharyngeal carcinoma (NPC) is most common in Southeast Asia. The purpose of this study is to investigate the correlation between wait time and length of radiotherapy and overall survival (OS) of NPC patients in Taiwan.


METHODS
From Taiwan's National Health Insurance Research Database, this nationwide population-based cohort study identified 3605 NPC patients who received radiotherapy between 2008 and 2011. The impact of time factors on NPC survival rates was estimated with Kaplan-Meier survival curves. A multivariable Cox hazards regression model tested the significance of results after adjustment for other covariables.


RESULTS
In all, 317 patients had wait times >4 weeks, 1404 patients had longer duration of radiotherapy (i.e., >10 weeks) and 499 died. Patients with wait times > 4 weeks and length of radiotherapy ≤ 10 weeks didn't have significantly inferior survival. Patients with wait times >4 weeks and length of radiotherapy >10 weeks had significantly lower OS than other groups, with an adjusted hazard ratio of 1.7 (95 % CI, 1.10-2.60).


CONCLUSIONS
Time was a significant prognostic factor for NPC patients who had both >4 weeks wait times and length of radiotherapy >10 weeks. Patients with wait time > 4 weeks and length of radiotherapy ≤ 10 weeks had a trend toward an inferior survival.
Department of Radiation oncology, Pingtung Christian Hospital, Pingtung, Taiwan.|Graduate Institute of Bioresources, National PingTung University of Science and Technology, Pingtung, Taiwan.
Po-Chun
PC
Chen
Department of Radiation oncology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.|School of Medicine, National Defense Medical Center, Taipei, Taiwan.
Wen-Shan
WS
Liu
Department of Radiation oncology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.|School of Medicine, National Defense Medical Center, Taipei, Taiwan.
Wei-Lun
WL
Huang
Department of Otolaryngology, Shung Ho Hospital, Taipei Medical University, Taipei, Taiwan.
Cheng-Jung
CJ
Wu
Department of Radiation oncology, Chi-Mei Medical Center, Tainan, Taiwan.
Ching-Chieh
CC
Yang
School of Medicine, National Defense Medical Center, Taipei, Taiwan. hematcd2@hotmail.com.|Department of Otolaryngology, Kaohsing Veterans General Hospital, No.386, Dazhong 1st Rd., Kaohsiung, Taiwan. hematcd2@hotmail.com.
Ching-Chih
CC
Lee
D000293:Adolescent; D000328:Adult; D000368:Aged; D002277:Carcinoma; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D005260:Female; D006297:Health Services Accessibility; D006801:Humans; D007223:Infant; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D016016:Proportional Hazards Models; D011878:Radiotherapy / Q000379:methods*; D012042:Registries; D015996:Survival Rate; D013624:Taiwan; D013997:Time Factors; D061665:Time-to-Treatment; D016896:Treatment Outcome; D055815:Young Adult
Nasopharyngeal carcinoma; Survival; Time factors; Treatment outcome