Accumulating evidence suggests that advanced age is associated with poor local control and prognosis in patients with soft-tissue sarcomas (STSs), highlighting the need to optimise treatment for this age group. However, real-world data on treatment details and outcomes in elderly patients are limited. This study aimed to clarify the role of perioperative radiotherapy (RT) for treating high-risk STSs in elderly patients.

Patients aged ≥ 70 years who underwent surgery for localised, high-grade, deep-seated non-small round cell STSs measuring ≥ 5 cm were included in the Bone and Soft Tissue Tumour Registry in Japan. Patients with small-round cell STSs or myxoid liposarcomas, or those who received perioperative chemotherapy or intraoperative RT, were excluded.

Among the 1,214 patients who met the criteria, 47 (4%), 219 (18%), and 2 (0.2%) received neoadjuvant, adjuvant, and both neoadjuvant and adjuvant RT, respectively. The 5- and 10-year disease-specific survival (DSS) rates were 72.7% and 64.7%, respectively. Tumour size ≥ 10 cm, intralesional margin, and local recurrence were associated with poorer DSS; however, perioperative RT did not affect DSS. The 5- and 10-year cumulative probabilities of local recurrence (LR) were 14.6% and 19.5%, respectively. Trunk wall tumours, dedifferentiated liposarcomas, marginal margins, and intralesional margins were associated with a higher probability of LR. Adjuvant RT was associated with a reduced LR probability in patients with intralesional (p = 0.005) or marginal margins (p = 0.044); however, no such benefit was observed in patients with wide margins, who constituted the majority of the cohort, resulting in no significant association between perioperative RT and LR in overall analyses. In the propensity score-matched cohort, no significant differences in DSS or cumulative probability of LR were observed between patients with and without perioperative RT.

Adjuvant RT was associated with reduced LR rates in elderly patients with high-risk STSs who had intralesional or marginal margins. In contrast, because most patients achieved wide margins and no benefit of perioperative RT was observed in this group, RT was not associated with reduced LR or improved survival in the overall or propensity score–matched analyses. Prospective trials are warranted to define the role of perioperative RT in elderly patients with high-risk STSs.