[Secondary neoplasms following tumor and leukemia therapy in childhood. Report of 64 cases].

64 second neoplasms, occurring after therapy of malignant tumors or leukaemia in childhood, came to light in the course of a collaborative group investigation. Most frequent initial diseases were acute lymphoblastic leukaemia (n = 19), Morbus Hodgkin (n = 9), and retinoblastoma (n = 8), whereas osteosarcoma (n = 13), cancer of the thyroid (n = 10) and acute non-lymphoblastic leukaemia (n = 8) were predominant among the second malignant neoplasms. In 36 of 50 irradiated children there was a clear relationship between the localisation of the second neoplasm and the earlier irradiated zone. In other cases, in particular in children with retinoblastoma as initial disease or neurofibromatosis, genetic influences on the origin of the second neoplasms come into question. The preponderance of Morbus Hodgkin after acute lymphoblastic leukaemia (n = 7) must be regarded as extraordinary; in 6 of the 7 children the second neoplasm appeared after a very short interval. A distinct effect of previous treatment with cytostatics on the occurrence of second neoplasms was not seen. The differing time intervals between the occurrence of the first and the second neoplasms in the separate subgroups point toward heterogenous causes being involved in the development of second neoplasms.