A comparison of the clinical characteristics of second primary and single primary sarcoma: a population based study.

The clinical characteristics of 240 patients with sarcoma as a second metachronous primary neoplasm (SPN) were compared with those of 8,815 patients with sarcoma as a single tumor. The data were obtained from patients registered during the period 1973-1986 in the Surveillance, Epidemiology and End Results (SEER) Program in the United States. Seventy-four of the 240 SPN patients had postirradiation sarcoma (PIS) while the other 153 patients developed the sarcoma as a second tumor in an area which was not exposed to prior radiotherapy (non-PIS). The stage of disease at diagnosis was more advanced in patients with PIS than in those with single sarcomas but the difference did not reach statistical significance. Overall, in comparable clinical stage localized and regional disease there was no statistically significant difference in survival between PIS and non-PIS sarcoma patients after adjusting for age. The survival of patients with localized or regionally advanced sarcoma as a second tumor was significantly worse than of those with single sarcomas with the same stage. There was no difference in survival between first or second sarcomas with metastatic disease.