Failure patterns and survival in pediatric soft tissue sarcoma

Abstract

We retrospectively analyzed 44 patients with localized soft tissue sarcomas who were seen and treated at the JCRT, DFCI, and TCH between 1970–1984. Patients with rhabdomyosarcoma were excluded. Primary tumors were located in the following sites: extremities 19 (43%), head and neck 9 (20%), and trunk 16 (37%). Median follow-up for survivors was 7.7 years (range 24 mo-16 years). Surgery was the initial aspect of treatment for all patients. All patients also received post-operative irradiation, 43 at presentation and one at local relapse, and 26 received adjuvant chemotherapy. Radiation was delivered to a dose of 4000 cGy (median) followed by a boost to a median dose of 5760 cGy (range 4500–7000 cGy). Actuarial 5- and 10-year disease-free survivals (DFS) were 70% and 59% while the actuarial 5- and 10-year overall survivals (OS) were both 75%. All parameters were assessed for significance by univariate analysis. OS was significantly affected by presenting stage when analyzed according to both the Intergroup Rhabdomyosarcoma Staging System (IRS) and the American Joint Committee on Cancer system (AJCC). For the IRS, OS at 10 years was 100% for Stage 1, 72% for Stage II, and 54% for Stage III ( p = 0.04). For the AJCC, OS at 10 years was 100% for Stage I and 65% for Stage II and III ( p = 0.05). Primary site, histology, and use of adjuvant chemotherapy did not influence OS or DFS. Fourteen patients failed: 8 local, 1 distant, and 5 combined local and distant. There was no LF among the 9 pts. with primary lesions <5 cm compared to 11 29 (39%) whose tumor was >5 cm ( p = 0.04). Pts. with gross residual disease had a local DFS of 42%, but those with no residual or microscopic residual had a local DFS of 71% ( p = 0.02). In conclusion, childhood STS has an excellent OS (75% at 10 years). Tumor size and residual tumor after surgery strongly predicted for local failure. Of interest, the pattern of failure is predominantly local in our series. This suggests that more aggressive local treatment is indicated in management of children with STS. Higher doses of irradiation as used for adult STS are probably indicated for patients with gross residual disease.