Variations in Retroperitoneal Soft Tissue Sarcoma Outcomes by Hospital Type: A National Cancer Database Analysis

Surgical resection remains the cornerstone of retroperitoneal soft tissue sarcoma (RPS) treatment. Patient- and sarcoma-related factors are well known to influence survival outcomes. The effect of hospital-related factors on long-term survival, however, are not well understood. We sought to assess the relative contribution of hospital-level factors to mortality after surgical treatment of RPS.

The 2004-2015 National Cancer Database was used to identify 10,113 patients who underwent surgical treatment of RPS. Patient-, sarcoma-, hospital-, and treatment-level factors were compared by increasing survival times. Stepwise multivariable Cox regression was performed that controlled for covariates to measure the relative contributions of these factors on overall survival (OS). Effect modification analyses ascertained how hospital type modulates the volume relationship with respect to RPS mortality.

Factors predictive of worsening OS were older age, nonprivate insurance, low income, presence of comorbidities, tumor histology, high grade or stage, and R2 resection (for all, P < .05). Increasing hospital surgical volume predicted decreasing risk of death across all survival times. However, analysis by hospital type demonstrated that compared with academic centers, the risk of death at community centers increased significantly as surgical volume increased (hazard ratio, 1.26; 95% CI, 1.03 to 1.53).

Hospital factors affect mortality after surgical treatment of RPS. Specifically, hospital type alters the surgical volume-outcome relationship for RPS mortality such that community centers perform worse with increasing volumes. Recommendations that higher surgical volume improves outcomes cannot be applied universally and must be re-examined in other complex surgical cancers.