Evaluating the Impact of Surveillance Follow-Up Intervals in Patients Following Resection of Primary Well-Differentiated Liposarcoma of the Retroperitoneum.

Background: Resection of recurrent retroperitoneal well-differentiated liposarcoma (RP-WDLPS) is unlikely to result in cure. Thus, most clinicians delay surgery after recurrence until symptom intolerance or increasing rate of disease progression. The aim of this study was to determine whether longer surveillance intervals in this population would impact outcomes or delay treatment in those who recur.

Methods: A retrospective review of patients with primary RP-WDLPS who underwent resection between April 1996 and April 2017 and surveillance at MDACC (n = 91) was performed.

Results: Median age at diagnosis of primary RP-WDLPS was 61 years; median tumor size was 30 cm. Complete resection was achieved in 85 (93.4%) patients. Among patients who underwent complete resection, recurrence occurred in 53 (60.2%) with median time to recurrence of 27.0 months. Thirty-six (69.6%) of these patients underwent resection of recurrent disease at a median 40.2 months from primary tumor resection. Surveillance imaging at 4-month (vs 3-month) intervals would not have impacted recurrence management in 84 (95.5%) patients; imaging at 6-month (vs 3-month) intervals would not have impacted management of recurrence in 80 (90.9%).

Conclusions: Recurrence was common, often occurring beyond the early postoperative period following primary RP-WDLPS resection. More frequent surveillance imaging (q3-4 vs q6 months) in the first 2 years following primary RP-WDLPS resection may not significantly impact timing of surgery or systemic therapy for recurrence. If longer surveillance intervals were shown to be safe with equivalent outcomes in prospective studies, the resulting change in practice could lead to decreased anxiety and cost for patients and healthcare systems.