Risk factors of childhood cancer in Armenia: a case-control study

Abstract

Background: Childhood cancer is a leading cause of death among children aged 0-19 years worldwide. Each year, 300,000 new cases of childhood cancer are diagnosed around the world. Given the differences between pediatric cancer incidence rates, types, and trends in different countries, it is important to conduct studies to find country-specific risk factors of this disease. To our knowledge, so far, no studies were conducted exploring factors associated with childhood cancer in Armenia. Aim: The aim of this study was to identify possible risk factors for childhood cancer in Armenia. Methods: The study used a case-control study design. The study setting was the only specialized pediatric hematology and oncology center in Armenia, located at the Hematology Center in Yerevan. The cases were patients of this center aged 14 years or younger, diagnosed with malignant disease. The controls were patients of the same center, but diagnosed with non-malignant disease. Data were collected from the hospital registry and followed with telephone interviews with mothers of the participants. The study instrument was developed and pretested prior to the data collection. The main domains of the questionnaire were: family sociodemographic characteristics, parental demographics, child health, pregnancy-related factors, and family environmental exposures. The analysis included descriptive, then simple and multiple logistic regression analyses to fit a model of risk factors of childhood cancer among the study population. Results: Overall, 234 participants (117 cases, 117 controls) were included in the study. The study identified that maternal usage of folic acid during pregnancy was protective against childhood cancer. Children born with these mothers had almost two times lower odds of developing cancer (OR=0.54; 95% CI: 0.31-0.94). On the contrary, experiencing horrifying/terrifying event(s) during pregnancy (OR=2.19; 95% CI: 1.18-4.07) and having induced abortions before getting pregnant with the given child (OR=2.94; 95% CI: 1.45-5.96) were associated with two-three-fold higher odds for a child to develop cancer. Conclusion: This study identified three important modifiable risk factors for childhood cancer in Armenia, all related to the period of pregnancy. These findings are consistent with the literature and indicate the need for improved pregnancy care, including education of reproductive age women and their family members on the importance of stress reduction during pregnancy, avoidance of induced abortions via practicing safe birth control methods and using folic acid prior to conception and during pregnancy.