Radiation therapy for retroperitoneal sarcoma: practice patterns in North America

The addition of radiation therapy (RT) to surgery in retroperitoneal sarcoma (RPS) remains controversial. We examined practice patterns in the use of RT for patients with RPS over time in a large, national cohort.

Patients in the National Cancer Database (2004–2017) who underwent resection of RPS were included. Trends over time for proportions were calculated using contingency tables with Cochran-Armitage Trend test.

Of 7,485 patients who underwent resection, 1,821 (24.3%) received RT (adjuvant: 59.9%, neoadjuvant: 40.1%). The use of RT decreased annually by < 1% (p = 0.0178). There was an average annual increase of neoadjuvant RT by 13% compared to an average annual decrease of adjuvant RT by 6% (p < 0.0001). Treatment at high-volume centers (OR 14.795, p < 0.0001) and tumor > 10 cm (OR 2.009, p = 0.001) were associated with neoadjuvant RT. In contrast liposarcomas (OR 0.574, p = 0.001) were associated with adjuvant RT. There was no statistically significant difference in overall survival between patients treated with surgery alone versus surgery and RT (p = 0.07).

In the United States, the use of RT for RPS has decreased over time, with a shift towards neoadjuvant RT. However, a large percentage of patients are still receiving adjuvant RT and this mostly occurs at low-volume hospitals.