Determinants of survival of common childhood cancers in Iran.

Background: Cancer is the second most common cause of morbidity and mortality in children. This study aimed to epidemiologically and demographically assess common cancers in children in Iran.

Materials and Methods: This cohort study was conducted on children registered in Mahak Hospital and Rehabilitation Complex (which is a non-governmental organizations (NGO)-related hospital for only malignant diseases). A total of 2232 questionnaires were filled out for cancer patients between 2007 and 2016. The factors including age, gender, race, family history, type of treatment, and type of cancer were entered into Cox regression model to examine their effect on mortality of children diagnosed with cancer.

Results: The Cox regression model showed that age, race, type of cancer, family history of cancer, and type of treatment had a significant effect on mortality of children diagnosed with cancer ( P < 0.05). The hazard ratio (HR) of mortality in 10-15 years old was higher than that of 1-5 years old ( P = 0.03, HR = 1.3). The HR of mortality in patients with brain tumor ( P < 0.01, HR = 2.24), sarcoma ( P < 0.01, HR = 2.32), and neuroblastoma ( P < 0.01, HR = 2.56) was twice the value in patients with leukemia. The HR of mortality in patients who had a family history of cancer was higher than that of patients without it ( P < 0.01, HR = 1.33). Patients who had undergone chemotherapy along with surgery and radiotherapy ( P = 0.02, HR = 0.68) and patients who received chemotherapy along with surgery ( P = 0.01, HR = 0.67) had a lower HR of mortality compared to the chemotherapy group.

Conclusion: Young age, multidisciplinary approach, and absence of family history were associated with lower hazard of death in children diagnosed with cancer; brain tumor, leukemia, and sarcoma had higher hazard of mortality compared to leukemia. Children with a family history of cancer should be under regular follow-up. Treatment should be multidisciplinary and comprehensive.