Incidence, Prevalence and Associated Risk Factors for Leukemia and Lyphoma Occurrence in Iran: A Systematic Review and Meta-analysis

Background: Leukemia and lymphoma account for the leading cause of death worldwide and in Iran. Numerous studies have been conducted with various results in different regions of Iran. The largest study was conducted on 18,353 lymphoma cases in Iran during 2003-2008. The present study aimed to gather a higher level of evidence for an aggregated 1,478,583 cases of leukemia and lymphoma. Objective: Risk factors and etiology of leukemia and lymphoma are variable in different parts of the country; therefore, identifying them is essential for prevention and better management. Method: The present study is a systematic review and meta-analysis to indicate the risk factors and to estimate the incidence of leukemia and lymphoma in Iran. All databases, including PubMed, Scopus, Springer, Cochrane, Google Scholar, were searched between 1970 and 2016. Out of the 152 selected articles in the preliminary search, 15 articles were reviewed, and the results of 11 studies were finally combined using the random-effects meta-analysis approach. The meta-regression and I₂ statistic were used to assess the heterogeneity. Data analysis was performed using STATA 12 software. Results: In addition to non-modifiable risk factors, modifiable risk factors are effective in the development of the disease. The incidence and overall prevalence of leukemia and lymphoma in Iran were estimated to be 3.26% (95% confidence interval: 2.7%-3.7%) and 7.15% (95% confidence intervals: 5.92%-8.37%), respectively. Conclusion: It can be stated that there is an increasing rate of hematologic cancers in Iran. This increase may be due to enhanced reporting and the presence of modifiable risk factors