Single-center experience with intra-abdominal liposarcoma: Optimal minimum duration for postoperative remnant tumor screening

This study sought to identify factors related to the prognosis of intra-abdominal liposarcoma and to determine the optimal minimum duration for remnant tumor screening. Intra-abdominal liposarcoma is associated with high rates of incomplete resection and recurrence requiring a sophisticated follow-up strategy. Patients who underwent surgery for intra-abdominal liposarcoma were included. Cox analyses were used to analyze factors related to recurrence and survival. To determine the optimal minimum duration for remnant tumor screening, patients with recurrence after surgery despite gross complete resection were grouped by a postoperative detection time of 1, 3, or 6 months. Their survivals were compared to the gross incomplete resection group. A total of 168 patients were included. Kaplan-Meier 5-year disease-free survival was 35.9% and overall survival was 66.5%. Multiplicity (HR=2.528, CI=1.585-4.033, P < .001), organ invasion (HR = 1.628, CI = 1.020-2.598, P = .041), and FNCLCC grades (G2,HR = 1.730, CI = 1.000-2.994; G3, HR = 3.812, CI = 2.112-6.880, P < .001) were related to recurrence. Multiplicity (HR = 2.131, CI = 1.050-4.329, P = .036), organ resection ≥3 (HR = 2.857, CI = 1.322-6.174, P = .008), gross incomplete resection (HR = 4.368, CI = 1.890-10.097, P = .001), positive margin (HR = 2.766, CI = 1.367-5.600, P = .005), FNCLCC grade (G2,HR = 2.044, CI = 0.937-4.459; G3,HR = 4.470, CI = 1.893-10.557; P = .003), and RT (HR = 0.322, CI = 0.160-0.648, P = .001) were related to overall survival. Dividing patients into 1 month (P = .097) and 3 months (P = 0.063) did not yield significant differences in univariate analyses, whereas 6 months showed significant difference (P = .015) compared to the gross incomplete resection group. Patients with tumors detected within 6 months showed similar survival to the gross incomplete resection group (HR = 0.552, CI = 0.241-1.260, P = .158), whereas patients with tumor detection after 6 months showed better survival (HR = 0.325, CI = 0.149-0.708, P = .005). In conclusion, minimum duration of 6 months for remnant tumor screening using CT seems optimal.