Treatment of pediatric malignant tumors with VP-16. West Japan Pediatric Oncology Group.

The West Japan Pediatric Oncology Group studied the treatment of pediatric malignant tumors with VP-16 from December 1984 to March 1988. Study subjects were divided into two groups. One group received only VP-16, while the other received VP-16 combined with other anti-tumor agents. VP-16 evaluation was possible in a total of 116 cases. The efficacy rate was calculated by considering both complete and partial remission as effective. The efficacy rate for VP-16 alone was 87.5% for primary cases of ANLL and 100% for primary cases of histiocytosis. The efficacy rates for combination therapy were as follows: 92.6% for primary cases of ANLL, 66.7% for primary cases of histiocytosis, 45.5% for relapsed cases of ANLL and 66.7% for relapsed cases of ALL. Bone marrow suppression was seen in the form of leukopenia and thrombocytopenia for 2 to 3 weeks after VP-16 administration. Alopecia, mucositis and gastrointestinal symptoms were also observed, but they presented no significant problem. From our results, we believe that chemotherapy including VP-16 is effective for remission induction therapy in primary cases of ANLL and for salvage therapy in relapsed leukemia. Additionally, VP-16 is considered to be effective for the treatment of histiocytosis.