Document Type: Systematic Review and Meta-analysis
Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences Tehran, Iran.
Gerash University of Medical Sciences, Gerash, Iran.
Department of Epidemiology, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
Department of Neurosurgery, Iran University of Medical Sciences, Tehran, Iran.
Vice-Chancellery for health, Isfahan University of Medical Sciences, Isfahan, Iran.
Health Management and Economics Research Center, Iran University of Medical Sciences, Tehran, Iran.
Background: Different studies have been conducted to estimate the survival rate of colorectal cancer in Iran but
there is no overall estimate of the survival rate. The aim of this study was to calculate the pooled 1, 3, and 5-year survival
rate of the patients with colorectal cancer in Iran. Methods: To retrieve relevant studies, we conducted a systematic
search in Iranian databases, including Iran Medex, Magiran, SID, and international databases such as Medlin/PubMed,
Scopus, and Google scholar using “Colorectal Neoplasms” and “Survival Rate” as keywords up to December 1st, 2017.
We used random effect model to estimate pooled 1, 3, and 5-year survival rates of the patients with colorectal cancer
in Iran. To assess the heterogeneity, we used Chi-squared test at the 5 % significance level (p <0.05) and I2 Index. We
used meta-regression and subgroup analysis to find a potential source of heterogeneity. Results: After a systematic
search, 196 articles were found, of the 38 studies met the eligibility criteria and are included in our meta-analysis. The
pooled 1, 3, and 5-year survival rates in patient with colorectal cancer were 0.84 (95% CI: 0.81-0.87), 0.64 (95%CI:
0.59-0.70), and 0.54 (95%CI: 0.49-0.58) respectively. The 5-year survival rate in the subgroup of women was 0.5
(0.44-0.56) and in male subgroup was 0.44 (0.40-0.48). In a subgroup of the tumor site, the 5-year survival rate in colon
cancer was 0.6 (0.49-0.75) and rectum cancer was 0.54 (0.36-0.69). In multivariable models, there was a significant
association between years of study and 5-year survival rate as a source of heterogeneity (β = 18.9, P=0.01). Conclusion:
According to the results of this study, women had a better survival rate than men, and according to the tumor site, the
5-year survival rate in colon cancer was better than the rectum cancer.