Incidence and Survival of Pediatric Soft Tissue Sarcomas: Comparison between Adults and Children / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Pediatric-type sarcomas such as rhabdomyosarcoma (RMS), Ewing sarcoma (EWS), primitive neuroectodermal tumor (PNET), and desmoplastic small round-cell tumor (DSRCT) are rare in adults, with limited studies on their prognosis and optimal treatment strategies. We aimed to examine the outcome of children and adult patients with RMS, EWS, PNET, and DSRCT and relevant prognostic factors. MATERIALS AND METHODS: We retrospectively reviewed 220 pediatric-type sarcoma patients at a single institution between 1985 and 2011. Comparisons were made in order to examine differences in demographics, disease characteristics, and survival. Survival analyses were performed using the Kaplan-Meier method with log-rank tests and Cox proportional hazards models. RESULTS: A total of 220 consecutive patients were identified at our institute. Median age was 15.6 years (range, 0 to 81 years) and there were 108 children (49%) and 112 adult patients (51%). According to histological classification, 106 patients (48.2%) had RMS, 60 (27.3%) had EWS, 50 (22.7%) had PNET, and 4 (1.8%) had DSRCT. With a median follow-up period of 6.6 years, the estimated median overall survival (OS) of all patients was 75 months (95% confidence interval [CI], 27.2 to 122.8 months) and median event-free survival (EFS) for all patients was 11 months (95% CI, 8.8 to 13.2 months). No significant difference in OS and EFS was observed between adults and children. In multivariate analysis, distant metastasis (hazard ratio [HR], 1.617; 95% CI, 1.022 to 2.557; p=0.040) and no debulking surgery (HR, 1.443; 95% CI, 1.104 to 1.812; p=0.012) showed independent association with worse OS. CONCLUSION: Metastatic disease and no surgical treatment are poor prognostic factors for OS among pediatric-type sarcomas for both adults and children.

Flow cytometric analysis of DNA ploidy in childhood rhabdomyosarcoma

Flow cytometric DNA analysis was performed on 17 rhabdomyosarcomas in conjunction with a histopathological review to determine the usefulness of this technique to predict the biologic behavior of the tumor and to establish the characteristic ploidy pattern of rhabdomyosarcoma compared to other small round cell tumors occurring in childhood. Aneuploidy including near-tetraploidy is the most common ploidy pattern encountered, followed by multiploidy and diploidy, and the presence of multiploidy in this tumor is useful for differentiating rhabdomyosarcoma from other kinds of small round cell tumors in which there are rare previous reports on occurrence of multiploidy. Even though there is no significant correlation between ploidy pattern and histologic type of rhabdomyosarcoma, patients with multiploid tumors or aneuploid tumors with a DNA index of 1.10-1.80 tend to have a high risk of treatment failure. Therefore, the ploidy pattern seems to be useful for predicting the patient's survival in concert with other variables.

Rhabdomyosarcoma in Children: Histologic Subtypes and Prognosis

Thirty cases of rhabdomyosarcoma in patients under the age of 15 years were reviewed retrospectively to find out characteristics of histologic subtypes related to prognosis. Histologic diagnosis were embryonal in 21(70%), alveolar in 7(23%) and mixed type in 2(7%). Cellular anaplasia was noted in 6 cases. Round to polygonal cells with abundant eosinophilic cytoplasmic rim or globules were most characteristic cytologic feature or rhabdomyosarcomas, being followed by myofibrils. Myxoid and edematous stroma in embryonal type and alveolar pattern in alveolar type wee nost characteristic growth pattern. Immunohistochemically, tumors were positive for desmin, actin and myoglobin in 97%, 27%, and 40%, respectively. Consequently, characteristic cytologic features are important to differentiate rhabdomyosarcomas form other kinds of small round cell tumor and growth pattern is more critical in categorizing histologic subtypes. Desmin is far more useful than actin or myoglobin in the diagnosis of rhabdomyosarcoma.