The radiation dose‐response of non‐retroperitoneal soft tissue sarcoma with positive margins: An NCDB analysis

• Published in: Journal of surgical oncology Vol. 120; no. 8; pp. 1476 - 1485
• Main Authors: Wells, Stacey, Ager, Bryan, Hitchcock, Ying J., Poppe, Matthew M.
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01-12-2019
• Subjects: Aged; Datasets as Topic; Female; Humans; Male; Margins of Excision; Middle Aged; Multivariate analysis; Neoadjuvant Therapy; positive margins; postoperative boost; radiation; radiation dose; Radiation therapy; Radiotherapy Dosage; Radiotherapy, Adjuvant; Retrospective Studies; Sarcoma; Sarcoma - mortality; Sarcoma - pathology; Sarcoma - therapy; Soft Tissue Neoplasms - mortality; Soft Tissue Neoplasms - pathology; Soft Tissue Neoplasms - therapy; United States - epidemiology; United States; postoperative boost; sarcoma; radiation dose; radiation; positive margins
• ISSN: 0022-4790; 1096-9098
• DOI: 10.1002/jso.25748

Objectives
Positive margins can increase the risk of local recurrence of soft tissue sarcomas (STS). Utilizing a national registry, we investigated patterns of care and overall survival (OS) of patients with margin‐positive non‐retroperitoneal STS who received preoperative radiation therapy, adjuvant radiation therapy, or both.
Methods
Adult patients with non‐retroperitoneal STS who underwent resection and RT from 2004 to 2015 were included. Kaplan–Meier, log‐rank analysis, and Cox regression analysis were performed.
Results
We identified 5726 patients. Most had a tumor size >5 cm (60%), grade 3 disease (67%), and microscopically positive margins (57%). Compared to ≤50.4 Gy, a dose of 66 to 69.99 Gy was associated with decreased risk of death on multivariate analysis (HR 0.69, 95%; CI, 0.50‐0.94). Receipt of a boost was associated with decreased risk of death on univariate analysis (HR 0.54, 95%; CI, 0.29‐0.99). In patients with grade 2 to 3 tumors without the gross disease, there was an OS benefit associated with a boost on multivariate analysis (HR 0.39, 95%; CI, 0.16‐0.97).
Conclusion
This analysis appears to show an OS benefit of dose escalation to 66 to 69 Gy for margin‐positive non‐retroperitoneal STS. A Postoperative boost is associated with higher OS in grade 2 to 3 STS without the gross disease.