Adipophilin expression is an independent marker for poor prognosis of patients with triple-negative breast cancer: An immunohistochemical study

Adipophilin is a lipid droplet-associated protein whose expression can act as a prognostic marker for specific cancers. Using immunohistochemical staining and tissue microarrays, we assayed the expression of adipophilin in 61 patients with triple-negative breast cancer (TNBC) who underwent surgery from January 2006-December 2018. Relapse-free survival (RFS) and its risk factors were analyzed based on adipophilin expression. Fourteen (23.0%) patients expressed adipophilin. As compared to the adipophilin-negative TNBC patients, adipophilin-positive patients exhibited poor RFS (p = 0.032). Among the TNBC patients with a high Ki-67 labeling index, patients negative for adipophilin exhibited better RFS than patients positive for adipophilin (p = 0.032). Moreover, among patients who did not undergo adjuvant chemotherapy, patients negative for adipophilin expression exhibited better RFS than adipophilin-positive patients (p = 0.080). Multivariate analysis showed that adipophilin expression correlated with a high rate of relapse (hazard ratio, 4.89; 95% confidence interval, 1.04-23.0; p = 0.044). Taken together, these results indicate that adipophilin is a novel marker for the poor prognosis of patients with TNBC.