Influence of biologic factors and anatomic site in completely resected liposarcoma

Soft tissue sarcoma (STS) encompasses a group of neoplasms that are anatomically and biologically diverse. Retroperitoneal/visceral (RP/V) tumors have a poorer prognosis than extremity/trunk (E/T) lesions, and this has been attributed to frequent presentation with tumors of large size and multiorgan involvement that precludes complete resection. The worse prognosis that is associated with RP/V tumors has also been thought to be histopathologically dependent and not necessarily related to anatomic site. The aim of this study was to determine the role of anatomic site and biologic features in prognosis and outcome in patients after complete resection by examining a large cohort of STS patients with a single histopathology, ie, liposarcoma.

All patients who were treated for liposarcoma from July 1, 1982, through July 1, 1998, were included. Univariate analyses were performed using log-rank test and Kaplan-Meier estimates, and multivariate analyses were performed using Cox regression. The three end points examined were local recurrence (LR), distant recurrence, and disease-specific survival (DSS).

Seven hundred twenty patients with liposarcoma were evaluated, and of these, 460 had completely resected primary or completely resected locally recurrent disease. Breakdown of anatomic site was 65% E/T (n = 301) and 35% RP/V (n = 159). The median follow-up period for patients who underwent complete resection was 42 months (range, 1 to 194 months). We found that RP/V site is a poor prognosticator that is independent of patient sex and age; tumor size, grade, and margin; and recurrent presentation. Sixty-nine percent of patients with RP/V tumors who died had local disease only and no distant metastasis at the time of death.

In liposarcoma, tumor location exerts as strong an influence on prognosis as biology. In contrast to extremity liposarcoma, LR without distant metastasis often results in death for patients with RP/V tumors. For these patients, local control accomplished by complete surgical resection +/- adjuvant radiation therapy should impact strongly on DSS.