Hibernation of masses suspected to be remnant tumors after surgical resection of retroperitoneal liposarcoma is related to improved overall survival.

BACKGROUND: Although complete surgical resection is considered the best treatment for retroperitoneal liposarcoma, it is related to a high local recurrence rate. This study analyzed patterns of recurrence of retroperitoneal liposarcoma.

METHODS: Records of patients who experienced recurrence after surgery for retroperitoneal liposarcoma from January 2000 to May 2017 were analyzed. Site, number, and characteristics of recurrent mass on computed tomography were serially collected. If a mass did not change size, it was considered a hibernating mass. Potential prognostic factors for overall survival were calculated using Kaplan-Meier survival log-rank tests.

RESULTS: A total of 74 patients, 28 within 6 months and 46 after 6 months, were detected as having a recurrence-suspected mass after surgery. Hibernation of a recurrence-suspected mass was found in 19 patients, 12 within 6 months and 7 after 6 months. While the presence of hibernation was not related to overall survival (P = 0.245), it was significantly related to improved survival in patients with a mass detected within 6 months (P = 0.022). Hibernation was not related to improved survival in patients with a mass detected after 6 months (P = 0.056).

CONCLUSIONS: Hibernation of a recurrence-suspected mass was related to improvement of overall survival in patients with a mass detected within 6 months. This specific patient group should be monitored with care to see if the size of the mass increases. When a mass seemed to be hibernating, a favorable prognosis could be expected.