Incidence and clinical characteristics of second malignant neoplasms in children: a multicenter study of a polish pediatric leukemia/lymphoma group.

BACKGROUND

The development of second malignant neoplasms (SMNs) in patients receiving chemotherapy and radiation therapy for primary cancers is one of the limitations to the quality and length of survival. The present study was undertaken to examine various characteristics of children who developed SMNs following successful therapy for primary leukemia or Hodgkin's disease (HD).

MATERIAL/METHODS: A total of 3252 children with various forms of leukemia and 849 children with HD treated between, 1970-1997 at 7 pediatric centers of the Polish Pediatric Hematology/Oncology Group and subsequently followed-up entered the study. A second malignancy was diagnosed in 36 of these children.

RESULTS

Of the 3252 patients diagnosed as having acute leukemia during this period, 16 developed SMNs (estimated frequency 0.49%). SMNs developed in 20 of the 849 children treated for HD (2.36%). The most frequent SMNs were soft tissue sarcoma and thyroid carcinomas, mainly following Hodgkin's disease. Other tumors occurred at about the same frequencies in both groups. The interval from the end of initial treatment to diagnosis of an SMN ranged from 2 years 7 months to 17 years 6 months, with a median of 7 yrs 4 mo. for acute lymphoblastic leukemia (ALL) patients and 10 years for children with HD. The estimated accumulated risk of SMN following acute leukemia is 0.95% at 15 years and, for HD, 5.1% at 20 yrs and 7% at 25 yrs.

CONCLUSIONS

Children who have been successfully treated for one cancer have a higher than expected incidence of additional tumors.