[Second neoplasms after malignant diseases in childhood].

Since 1980 the German Registry of Childhood Malignancies has been established. In the framework of the long-term follow-up secondary malignancies are reported continually to the registry. An additional retrospective inquiry to all treating clinicians and principal investigators of clinical trials as well as a link to a previously existing pool of secondary malignancies (1) lead to a completion of the data. At the registry now 329 patients with second malignant neoplasms have been observed. 41.3% of them had been developed the first malignancy before the registry started its work in 1980. The most common primary malignancies are acute lymphoblastic leukaemia (ALL, 28.6%), brain tumours (12.2%), and retinoblastomas (8.8%). Compared to the population of the registry retinoblastomas as a secondary malignancy occur in excess (2.5% vs 8.8%). Most common secondary malignancies are brain tumours (20.1%), acute non-lymphoblastic leukaemia (13.1%), osteosarcomas (10.9%), and thyroid carcinomas (6.1%). Hereby especially for thyroid cancer a remarkable deviation from the frequency in the total population of the registry (0.2%) is observed. In 3% of the patients a secondary malignancy appears within a span of 10 years after the primary malignancy. This is a twentyfold increase compared with the cumulative rate of developing a malignancy in the first 10 years of life. Brain tumours after ALL (8.5%) and after other brain tumours (5.8%) and osteosarcomas after retinoblastomas (4.9%) are the most often reported combinations.(ABSTRACT TRUNCATED AT 250 WORDS)