Long-term sequelae of malignant tumors in childhood: consequences of late side-effects

110 children with malignant diseases (leukemia excepted) who survived 5-20 years (median 9) post-therapy were followed (1996-1998). Median age during follow-up was 15 years (range 5-23). The most common malignancies were brain tumors, lymphoma, retinoblastoma and Wilm's tumor. The 174 late side-effects included endocrine disorders (19%), cognitive impairment (14%), orthopedic dysfunction (12%), alopecia (12%), dental damage (11%), psychological (8%) and neurological (8%) disturbances, and azoospermia or amenorrhea (5%). There was no cardiac or renal damage and no second malignancy. 29% of side-effects were severe. There was significant reduction in quality of life in 54 (49%), in 27 of whom it was severe enough to require psychological intervention. Treatment of brain tumor caused 98 late side-effects in 28 patients (sequelae-to-patient ratio [SPR] 3.3). Most cognitive, endocrine and neurological disorders, and most cases of alopecia, dental and psychological difficulties were in these patients. There were frequent late complications in those treated for retinoblastoma (SPR 1.8), and bone or soft tissue sarcomas (SPR 0.8). Those treated for Wilm's tumor had few side-effects (SPR 0.4). Late side effects were most frequent after radiation, reaching as high as SPR 2.4. It averaged only 0.5 in those treated with chemotherapy alone or in combination with surgery. Reduction of late side-effects in these patients requires using less toxic modalities, as long as cure rate is not compromised. When considering secondary strategies, screening for early detection of late complications would enable immediate solutions, such as hormonal replacement or providing compensating skills for post-treatment disability.