Patterns of recurrence and survival probability after second recurrence of retroperitoneal sarcoma: A study from TARPSWG.

Background: In this series from the Transatlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG), the authors examined longitudinal outcomes of patients with a second recurrence of retroperitoneal sarcoma (RPS) after complete resection of a first local recurrence (LR). Methods: Data from patients undergoing resection of a first LR from January 2002 to December 2011were collected from 22 sarcoma centers. The primary outcome was overall survival (OS) after second recurrence. Results: Second recurrences occurred in 400 of 567 patients (70.5%) after an R0/R1 resection of a first locally recurrent RPS. Patterns of disease recurrence were LR in 323 patients (80.75%), distant metastases (DM) in 55 patients (13.75%), and both LR and DM in 22 patients (5.5%). The main subtype among the LR group was liposarcoma (77%), whereas DM mainly were leiomyosarcomas (43.6%). In patients with a second LR only, a total of 200 patients underwent re‐resection (61.9%). The 5‐year OS rate varied significantly based on the pattern of failure (P <.001): 45.6% for the LR group, 25.5% for the DM group, and 0% for the group with LR and DM. The only factors found to be associated with improved OS on multivariable analysis were both time between second surgery and the development of the second recurrence (32 months vs 8 months: hazard ratio, 0.44 [P <.001]) and surgery for second recurrence (yes vs no: hazard ratio, 3.25 [P <.001]). The 5‐year OS rate for patients undergoing surgery for a second LR was 59% versus 18% in the patients not deemed suitable for surgical resection. Conclusions: Survival rates after second recurrence of RPS varied based on patterns of disease recurrence and treatment. Durable disease‐free survivors were identified after surgery for second LR in patients selected for this intervention. The current series, derived from 22 sarcoma centers from the Transatlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) collaborative, describes the outcomes of patients experiencing a second recurrence of retroperitoneal sarcoma. Second recurrences are reported in approximately 70.5% of patients, with a 5‐year overall survival rate of between 0% and 45%, but durable disease‐free survivors are identified after surgery for second local recurrence among selected patients. [ABSTRACT FROM AUTHOR]