Differential impacts of initial treatment status on long-term survival in patients with sarcomas treated in a referral center according to histologic type and anatomic site.

Objective: The aim of this work was to estimate the magnitude of the differential impacts of initial treatment status relative to the impact of classic clinicopathologic factors on the long-term overall survival (OS) of sarcoma patients in a referral cancer center.

Methods: From the institutional database, we identified 2185 patients who presented to the institutional multidisciplinary team (MDT) prior to (N = 717, 32.8%) or after (N = 1468, 67.2%) initial treatment, with a first diagnosis of sarcoma from January 1999 to December 2018. Descriptive, univariate and multivariate analyses were applied to identify the factors related to OS. By performing propensity score matching of each completely MDT-treated patient to a referral patient with similar characteristics, the differential impacts of the identified risk and prognostic factors on OS in the 2 groups were estimated by the Kaplan‒Meier survival curves, log-rank test and Cox proportional hazard regression; the results were compared using calibrated nomograph models and forest plots.

Results: Adjusted for the clinicopathologic factors of patient age, sex, primary site, tumor grade, tumor size, resection margin and histology, hazard ratio-based modeling analysis indicated that the initial treatment status was an independent but intermediate prognostic factor associated with long-term OS. The major impacts of the initial and comprehensive MDT-based management on significant improvement of the 20-year OS of sarcomas were reflected in the subgroup of patients with stromal, undifferentiated pleomorphic, fibromatous, fibroepithelial, or synovial neoplasms and tumors in the breast, gastrointestinal tract, or soft tissues of limb and trunk.

Conclusions: This retrospective study supports early referral of patients with soft tissue masses of unknown identity to a specialized MDT before biopsy and initial resection to reduce the risk of death but highlights an unmet need for a greater understanding of some of the most difficult sarcoma subtypes and subsites and their management.