The aim of this retrospective study was the determination of the frequency and the course of HBV infection in children with neoplastic disease and an evaluation of its influence on treatment results during a time period before hepatitis B vaccination was available. Eighty-nine (89) children were included in the study. The period of time studied for individuals ranged from 6 months to 15 years. Hepatitis B infection was detected in 59 of 89 (66.3%) patients. During the first year of neoplastic disease treatment the infection occurred in 49 children (83.1%). Spontaneous virus elimination after completing chemotherapy occurred in only 2/59 (3.45%) patients. The probability of long-term survival of HBV infection in this group was 0.965. Chronic hepatitis was diagnosed in 23/59 (39%) children infected and in 3/30 (10%) of the children not infected with HBV .

Keywords: hepatitis B virus infection, children, neoplastic disease, event free survival, recurrences, chronic hepatitis