Nrf2 Expression is Associated with Poor Outcome in Osteosarcoma

Aims: 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.

Methods: Nrf2 expression was assessed using immunohistochemistry in 58 specimens from patients with osteosarcoma. We investigated whether Nrf2 expression was associated with clinicopathological parameters.

Results: 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.

Conclusion: 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.