Document Type : Research Articles
Modeling in Health Research Center and School of Public Health, Department of Epidemiology and Biostatistics, Shahrekord University of Medical Sciences, Shahrekord, Iran.
Department of Biostatistics, School of Paramedicine, Shahid Beheshti University of Medical Science, Tehran, Iran.
Department of Epidemiology and Reproductive Health, Reproductive Epidemiology Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
Department of Epidemiology and Biostatistics, Tehran University of Medical Sciences, Tehran,Iran.
School of Public Health, University of Alberta, Edmonton, Alberta, Canada.
Objective: Esophageal cancer (EC) is one of the gastrointestinal malignancies with a very high morbidity and
mortality rate due to poor prognosis. This study aims to assess the effects of risk factors on survival and cure fraction of
patients with EC in a population of Iranian patients using a non-mixture cure fraction model. Methods: This retrospective
cohort study was conducted on 127 patients with EC who were diagnosed during 2009-2010 and were followed
up for 5 years in East-Azarbaijan, Iran. Stepwise selection and non-mixture cure fraction model were used to find
the risk factors of EC survival patients. Results: The mean (±standard deviation) diagnosis age of the EC was
66.92(±11.95). One, three and five-year survival probabilities were 0.44 (95% confidence interval (CI): 0.36-0.54),
0.2 (95% CI: 0.14-0.28) and 0.13 (95% CI: 0.08-0.2) respectively. Female sex (Estimate=-0.99; 95% confidence interval
(CI): -1.41,-0.58; p-value<0.001), low level socioeconomic status (Estimate=0.39; 95%CI: 0.12,0.66; p-value=0.043),
the group who did not do esophagectomy surgery (Estimate=0.58; 95%CI: 0.17,0.99; p-value=0.005) and unmarried
group (Estimate=0.58; 95%CI: 0.11-1.05; p-value=0.015) were found as the significant predictor of survival and
cure fraction of the EC patients. Population cure rate was 0.11 (95%CI: 0.07-0.19) and Cure fraction was estimated
5.11 percent. Conclusion: This study found gender, socioeconomic status, Esophagectomy surgery and marital status
as the potential risk factors for survival and cure fraction of Iranian EC patients. Moreover, non- mixture cure fraction
provides more accurate and more reliable insight into long-term advantages of EC therapy compared to standard classic
survival analysis alternatives.