Thromboembolism in children with cancer: a retrospective multicenter study in Korea.

Thromboembolism (TE) is a major cause of morbidity and mortality in adult cancer patients; however, there is a lack of sufficient knowledge on TE in pediatric cancer patients. We aimed to determine the epidemiology of TE in Korean children with cancer. Between January 2000 and July 2015, we retrospectively analyzed pediatric patients newly diagnosed with cancer at six tertiary hospitals in Korea. Of 3611 children with cancer, 33 (0.91%) had TE. A higher number of patients with acute lymphoblastic leukemia (n = 13), brain tumors (n = 6), lymphoma (n = 4), and bone/soft tissue sarcomas (n = 5) tended to develop TE. The male/female ratio was 17/16, and the median age at TE diagnosis was 10 years and 2 months. TE was detected a median of 2 months after cancer diagnosis. Symptoms including pain and swelling were present in 18 of the 33 patients. In terms of location, three intracerebral, 23 upper venous, six lower venous and one combined upper and lower venous system TEs were observed. Additional risk factors for TE included central venous catheter (CVC) use in 12 patients, steroid and/or L-asparaginase use in nine, and CVC and steroid and/or L-asparaginase use in seven. The TE incidence rate was quite low among Korean children with cancer, but higher than in the general pediatric population and among children hospitalized for diseases other than cancer. Further investigation of a larger pool of patients is warranted to determine the most effective strategies to prevent and treat TE in Korean children with cancer.