Friday, April 23, 2010

JCO: Prognosis with Radiation Associated Sarcomas

From the JCO:

An interesting series of radiation associated soft tissue sarcomas from MSKCC, which attempts to determine if there are differences in the prognosis with a matched cohort of sporadic STS. The DSS was indeed different with an HR of 1.7(p=0.007) on MVA, however, it is significant to note that the radiation associated tumors were not given RT as often (~50% less). How this difference in treatment may have affected outcomes is uncertain, however this could certainly contribute to the difference outcomes. Regardless, it is a worthwhile subject of study, and the mansucript is worth review for the practicing radiation oncologist.

Link and Abstract:

Do Radiation-Associated Soft Tissue Sarcomas Have the Same Prognosis As Sporadic Soft Tissue Sarcomas? [Sarcomas]: "Purpose

To determine the prognostic significance of histologic type in radiation-associated soft tissue sarcomas (RASs) and determine whether RASs are associated with an inferior prognosis compared with sporadic soft tissue sarcomas (STSs).

Patients and Methods

One hundred thirty primary RASs were identified from 7,649 STS patients from 1982 to 2007. Multivariate analysis of clinicopathologic factors for disease-specific survival (DSS) was performed for RASs, and a multivariate analysis of radiation exposure was also performed for RASs and sporadic sarcomas. A matched-cohort analysis was performed for radiation-associated and sporadic malignant fibrous histiocytoma (MFH).


Most RASs were high grade (83%), deep (87%), and truncal (61.5%). The median interval between radiation therapy and RAS development was 10 years (range, 1.3 to 74 years), which varied significantly by histologic type (P = .003). The 5-year DSS was 58%, and independent predictors were size > 5 cm, margin positivity, and histologic type. Multivariate analysis of histologic types of primary, high-grade radiation-associated and sporadic STSs showed that RAS was associated with a worse DSS (hazard ratio, 1.7; range, 1.1 to 2.4; P = .007). For pleomorphic MFH—the most common RAS type—the 5-year DSS was 44% versus 66% in a matched cohort of sporadic MFH patients (P = .07). DSS was significantly worse in primary RAS malignant peripheral nerve sheath tumors (MPNSTs) compared with unmatched sporadic MPNSTs (P = .001).


Histologic type, margin status, and tumor size are the most important independent predictors of DSS in patients with RASs. DSS in patients with primary RAS is significantly worse compared with sporadic STS independent of sarcoma histologic type."

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