Local Recurrence and Metastasis Define Distinct Recurrence Phenotypes in Soft Tissue Sarcoma

Area of Science:

• Oncology
• Surgical Oncology
• Sarcoma Research

Background:

• Soft tissue sarcomas (STS) exhibit clinical heterogeneity.
• Local recurrence (LR) and metastasis are often analyzed separately.
• The interaction between local and metastatic disease in STS recurrence requires further investigation.

Purpose of the Study:

• To define distinct recurrence phenotypes in STS based on the interplay of local and metastatic disease.
• To analyze tumor characteristics, treatment, surgical factors, and event sequences across different recurrence phenotypes.
• To elucidate the clinical significance of local recurrence within the context of metastatic disease.

Main Methods:

• Analysis of prospective registry data from 668 patients with histologically confirmed STS.
• Stratification of patients into four recurrence phenotypes: no event, metastasis only, LR only, and combined LR and metastasis.
• Statistical analysis of tumor grade, location, recurrence timing, and event sequence.

Main Results:

• Recurrence phenotypes were distributed as: no event (52.2%), metastasis only (23.8%), LR only (13.5%), and combined (10.5%).
• High-grade tumors (G3) were significantly more frequent in metastasis-only and combined recurrence phenotypes.
• Early LR was more common in the combined phenotype, while late LR predominated in isolated LR cases. High grade and axial location independently predicted combined recurrence.

Conclusions:

• STS recurrence is characterized by distinct phenotypes resulting from the interaction between local and metastatic disease.
• The clinical impact of local recurrence is significantly influenced by its association with metastatic events.
• Identifying these recurrence phenotypes offers a more nuanced understanding for improved STS management.