Nrf2 expression is associated with poor outcome in osteosarcoma

Abstract

NF-E2-related factor 2 (Nrf2) is involved in defence against oxidative stress in human cells. Nrf2 is over-expressed in many types of cancers suggesting that it plays a role in carcinogenesis and chemoresistance. We examined Nrf2 expression in osteosarcoma to determine its prognostic significance. Nrf2 expression was assessed using immunohistochemistry in 58 specimens from patients with osteosarcoma. We investigated whether Nrf2 expression was associated with clinicopathological parameters. Nrf2 was positively expressed in 19 (32.8%) of 58 specimens. Nrf2 expression in osteosarcoma indicated a poor prognostic outcome (p = 0.0074), and correlated with worse disease-free survival (p = 0.0279). Nrf2 expression had a significant relationship with histological subtype (osteoblastic versus non-osteoblastic, p = 0.042); the non-osteoblastic subtype showed a higher rate of Nrf2 expression (50.0%) than the osteoblastic subtype (23.7%). Nrf2 expression showed no significant relationship with response to neoadjuvant chemotherapy (p = 0.115). Other clinicopathological parameters had no relationship with Nrf2 expression. Increased expression of Nrf2 is associated with a poor outcome and disease-free survival in osteosarcoma. Our results suggest that Nrf2 is a possible marker of poor prognosis in osteosarcoma.