Prevalence of hereditary cancer susceptibility syndromes in children: A report from the Saudi Arabian Pediatric Hematology Oncology Society.

Abstract

Background: Hereditary cancer susceptibility syndromes (HCSS) contribute to the cause of up to 29% of childhood cancer. The Saudi population has high rate of consanguineous marriages and this might increase the prevalence of HCSS. Methods: Our study is a cross sectional multi-center study of children less than age 14 years who were diagnosed with cancer between January 2011 and December 2014. Data collected were: demographics, number of primary cancers, and cancer details. Parents were interviewed about consanguinity and the occurrence of cancer in 1st, 2nd, and 3rddegree relatives. HCSS risk assessment was based on the ACMG 2015 practice guidelines. The study was funded by Sanad children's cancer support association. Results: A total of 1291 patients (leukemia 49%, lymphoma 11%, brain tumors 10%, non-Ewings sarcoma 7.3%, Wilms tumor 6.1%, and others 16.6%) were enrolled as of December 2015. The median age at diagnosis was 5.1 years, male:female ratio was 1.3:1, and median sibship size was 4 (range, 0-12). Parental consanguinity was reported in 38%, mostly first degree. The number of patients with criteria that warrants HCSS work up is shown in the Table. A total of 486 (37.6%) met those criteria (leukemia 58%, non-Ewings sarcoma 19.4%, brain 12.8%, retinoblastoma 4.9%, hepatoblastoma 4.5%, and adrenocortical carcinoma 0.4%). Conclusions: Nearly 4 out of 10 children with cancer in Saudi Arabia met criteria for HCSS, most often due to parental consanguinity. The use of consanguinity solely as a risk factor for HCSS in our population needs to be determined. Genetic testing of at risk patients is on-going. (Table Presented).