Multifocality in retroperitoneal sarcoma: a prognostic factor critical to surgical decision-making

Area of Science:

• Oncology
• Surgical Oncology
• Sarcoma Research

Background:

• The prognostic impact and clinical characteristics of multifocal retroperitoneal sarcoma (RPS) are not well-defined.
• A standardized definition for sarcomatosis, a condition involving multiple sarcoma tumors, is currently lacking.

Purpose of the Study:

• To determine the impact of multifocality on overall survival (OS) in patients diagnosed with retroperitoneal sarcoma (RPS).
• To establish a data-driven definition of sarcomatosis that is prognostically and therapeutically relevant.

Main Methods:

• Retrospective analysis of 393 patients with primary or recurrent nonmetastatic RPS treated between 1996 and 2006.
• Comparison of baseline and treatment variables between unifocal and multifocal disease groups.
• Multivariate analysis to assess multifocality's association with OS and identify other prognostic factors in multifocal RPS.

Main Results:

• Multifocal disease was present in 20% of patients (79/393).
• Five-year OS rates were significantly lower for multifocal RPS (31%) compared to unifocal RPS (60%).
• Multifocality independently predicted worse OS (HR 1.7, P=0.004); >7 tumors indicated a worse prognosis (HR 2.1, P=0.03) with a 5-year OS of 7%.

Conclusions:

• Multifocal RPS is associated with diminished overall survival in both primary and recurrent cases.
• Identifying patients with >7 tumors provides a criterion for defining sarcomatosis and predicting poor prognosis.
• This definition aids in identifying patients who would benefit most from systemic therapy.