Isolated limb perfusion for liposarcoma : Histopathological response and subgroup analysis after TNF melphalan-based ILP

Abstract

Tumor necrosis factor alpha (TNF) and melphalan-based isolated limb perfusion (TM-ILP) is one of the most effective treatment modalities for unresectable soft tissue sarcoma (STS) of the extremities. Liposarcomas (LS) are alarge and heterogeneous subgroup of STS with different biological behavior and prognoses. The aim of this study was to evaluate LS and the different subentities with respect to their responsiveness towards TM-ILP. We matched our ILP database with our pathology database to identify patients who received TM-ILP due to STS followed by resection of the residual tumor. We identified 126 patients who matched these inclusion criteria. In this patient group we identified 24 patients with aLS. Histopathological regression was assessed from all resection specimens and was compared between groups: LS vs. non-LS and for myxoid and non-myxoid LS subgroups. There were no significant differences in the overall tumor regression comparing non-LS (median 95%, mean 77%) and LS (median 90%, mean 74%). For the subgroup analysis, ahigher grade of regression after TM-ILP was found in myxoid-LS (median 95%, mean 79%± 31.5) compared to the non-myxoid LS (median 75%, mean 72%± 24.6). Atypical lipomatous tumors (ALT) were less responsive to TM-ILP treatment (median 40%, mean 40%). The histopathological response of LS toward TM-ILP is equally good compared to non-lipomatous STS. Myxoid LS seem to have atendency towards abetter response to TM-ILP compared to non-myxoid LS and ALT showed the lowest response rate in the liposarcoma subgroup. Furthermore, we found that TM-ILP seems to facilitate successful R0 resection. Due to the low number of cases in the subgroups we advocate further research on this topic.