2ND MALIGNANT NEOPLASMS IN CHILDREN AFTER TREATMENT OF SOFT-TISSUE SARCOMA

Currently, approximately 67% of children diagnosed with cancer can be expected to survive more than 5 years. Among the most significant late effects of cancer therapy is the development of second malignant neop lasm (SMN). This study was performed to identify the factors associate d with the development of second malignant neoplasms after treatment f or soft tissue sarcomas in childhood. Retrospectively the charts of 20 children who developed second malignant neoplasms after treatment for primary childhood soft tissue sarcoma were reviewed. Presentation, ag e at diagnosis, tumor histology, extent of tumor, treatment, family hi stories (when available), and outcome were recorded. The mean age of t he patients (10 boys, 10 girls) was 8.5 years of age (range, 1 to 20 y ears). Most primary tumors were rhabdomyosarcoma (14/20) and occurred in an extremity (10/20). Ninety percent of the patients (18/20) had a complete response to treatment of the primary cancer. Eleven out of 20 received combined chemotherapy and radiation therapy. The most common secondary malignancy was a bone sarcoma (6/20), followed by brain tum ors (n = 3), leukemia (n = 2), and other sarcomas (n = 2). Four of the bone sarcomas developed in the field of radiation treatment. Median f ollow-up was 16 years (range, 1 to 26 years). The median time to devel opment of a SMN was 11.4 years (range, 1.5 to 21 years). Survival afte r a second malignancy was only 30%. Two patients developed a third mal ignant neoplasm. The occurrence of a secondary malignancy represents a serious complication of childhood cancer. Certain tumors are related directly to treatment such as osteosarcoma within irradiated fields an d secondary leukemias or lymphomas after certain chemotherapy regimens . Combined radiotherapy and chemotherapy may play an additive role in the development of second malignant neoplasms. Genetic factors may pre dispose affected patients to the development of both primary and secon dary malignancies. Close surveillance of children previously treated f or childhood cancers is warranted. Copyright (C) 1997 by W.B. Saunders Company.