Prognostic implications of the immunohistochemical expression of perilipin 1 and adipophilin in high-grade liposarcoma.

Aims: Liposarcoma is a malignant soft tissue tumour with adipocytic differentiation. Dedifferentiated liposarcoma (DDLS) and myxoid liposarcoma (MLS) are classified as high-grade liposarcomas. Lipid droplet-associated protein (also known as perilipin 1 (PLIN1)) is the predominant perilipin and has utility as a specific marker of adipogenic differentiation. Adipose differentiation-related protein (also known as adipophilin (ADRP)) is ubiquitously expressed in a range of tissues. High ADRP expression is reportedly a poor prognostic factor in several cancer types. However, no previous studies have examined the association between PLIN1 or ADRP expression and prognosis in sarcoma. This study therefore aimed to evaluate the association between PLIN1 or ADRP expression and prognosis in liposarcoma.

Methods: In total, 97 primary resection specimens (53 MLS and 44 DDLS) were examined in this study. PLIN1 and ADRP expression was evaluated by immunohistochemistry. Survival analyses were performed for MLS and DDLS.

Results: Of the 53 MLS specimens, 15 (28.3%) exhibited high PLIN1 expression. PLIN1 expression was not observed in DDLS specimens. High PLIN1 expression was significantly associated with increased disease-free survival (DFS) among patients with MLS (p=0.045). Distinct ADRP expression was observed in 13 of 53 (24.5%) MLS specimens and 5 of 44 (11.4%) DDLS specimens. High ADRP expression was associated with shorter overall survival (OS) in MLS (p=0.042) and DFS and shorter OS in DDLS (p=0.024 and p<0.001, respectively).

Conclusions: PLIN1 and ADRP expression is associated with poor prognosis in high-grade liposarcoma.