The Use of Radiation Therapy in Localized High-Grade Soft Tissue Sarcoma and Potential Impact on Survival

It is a consensus that radiation therapy (RT) should be applied for all large, deep, high-grade soft tissue sarcomas (STS). Therefore, we investigated the National Cancer Database (NCDB) to study how these guidelines are being followed, to determine what factors may be associated with the decision not to use RT, and to see whether there was an association of RT use and survival.

We retrospectively analyzed localized high-grade STS patients in the NCDB from 1998 through 2006. They were further stratified into two groups: no radiation (NRT) group and radiation (RT) group. Then, long-term survival between the two groups was evaluated using the Kaplan–Meier (KM) method with comparisons based on the log-rank test. Multiple variables were analyzed between the two groups. Propensity matching was performed secondarily to minimize the influence of confounding variables.

A total of 3982 of 10,290 patients (37.8 %) did not receive RT and 6,308 patients (62.2 %) did receive RT. Patients in the NRT group were more likely to have a below-median education level (median 58.2 % vs. 60.7 %; p = 0.015) and a below-median income level (65.1 % vs. 68.6 %; p < 0.001). In addition, these patients lived farther from their treatment centers (20.2 vs. 14.8 miles, p = 0.002) and were more likely to be uninsured (5.3 % vs. 3.5 %, p < 0.001). They were less likely to receive a radical excision (55.2 % vs. 70.1 %; p < 0.001) and more likely to receive amputation (20.9 % vs. 3.3 %; p < 0.001). The 30-day mortality (1.2 % vs. 0.2 %; p < 0.001) and readmission rate (3.8 % vs. 2.8 %; p = 0.031) were higher for the NRT group. KM analysis showed that long-term survival for patients who did not receive RT was significantly lower, even after propensity score matching (p < 0.001).

This large database review reveals a striking lack of utilization of RT to treat high-grade STS, which correlates with poorer survival even after propensity matching. Lower education and income levels and diminished access to medical care (insurance and distance to the facility) are associated with failing to receive RT.