SUOX is a promising diagnostic and prognostic biomarker for hepatocellular carcinoma.

Background & Aims: To investigate diagnostic and prognostic values of sulfite oxidase (SUOX) in patients with hepatocellular carcinoma (HCC) who underwent curative resection.

Methods: We investigated immunohistochemically the expression dynamics of SUOX, aldo-ketoreductase family 1 member B10 (AKR1B10) and CD34 at different stages of HCC. The differential diagnostic performance of three markers or their combinations in high-grade dysplastic nodules (HGDNs) and well-differentiated small HCC (WD-sHCC) were investigated by logistic regression models and validated in an independent testing set. Overall survival (OS) and time to recurrence (TTR) were evaluated in 300 patients with HCC as the testing cohort, and validated in 198 patients with HCC.

Results: SUOX was decreased and AKR1B10 and CD34 were increased with the stepwise progression of hepatocarcinogenesis. For differential diagnosis of WD-sHCC from HGDNs, the sensitivity and specificity of the SUOX+AKR1B10+CD34 combination for WD-sHCC detection were 93.8% and 95.2%, respectively, and overall accuracy was much higher than any of the three individual markers and two marker combinations. In addition, SUOX, but not AKR1B10 and CD34, was an independent prognostic factor for OS and TTR, and showed better correlation with OS and TTR if combined with serum α-fetoprotein (AFP) for both the testing and validation cohorts.

Conclusions: SUOX+AKR1B10+CD34 combination could make a substantial contribution to hepatic immunopathological diagnosis to distinguish WD-sHCC from HGDNs. Meanwhile, SUOX combined with serum AFP may predict postoperative outcome and tumor recurrence risk.