Prognostic Significance of SULF2 Expression in Surgically Resected Non-Small Cell Lung Cancer

Background: Sulfatase 2 (SULF2) is an extracellular enzyme involved in the modulation of multiple oncogenic signaling pathways and has been implicated in tumor progression across several malignancies. However, its prognostic significance in surgically resected non-small cell lung cancer (NSCLC) remains incompletely defined. Methods: SULF2 expression was evaluated by immunohistochemistry in tumor specimens from patients with stage I–III NSCLC who underwent curative-intent surgical resection between 2009 and 2016. Expression levels were quantified using an H-score-based system and categorized as low or high. Associations between SULF2 expression, clinicopathological characteristics, and survival outcomes, including overall survival (OS) and disease-free survival (DFS), were analyzed using Kaplan–Meier estimates and Cox proportional hazards models. Eighty-three patients were included, of whom 65 (78.3%) were male; 42.2% had stage I disease, 32.5% stage II, and 25.3% stage III. Results: SULF2 expression was detected in 94.0% of tumors, with 43 patients (51.8%) classified as high and 40 (48.2%) as low expression based on H-score. Overall survival and DFS did not differ significantly between SULF2-low and SULF2-high groups (log-rank p = 0.213 and p = 0.660, respectively). Median OS was 113.2 months (95% CI: 84.0–142.4) in the SULF2-low group and 54.9 months (95% CI: 39.4–186.9) in the SULF2-high group, while median DFS was 88.3 months (95% CI: 46.5–130.2) and 53.3 months, respectively, with numerically shorter survival in the SULF2-high group. Conclusions: Subgroup analyses stratified by pathological stage and histological subtype revealed no significant associations between SULF2 expression and survival outcomes. In multivariate analysis, SULF2 expression was not independently associated with either OS or DFS. SULF2 expression was highly prevalent in surgically resected NSCLC; although higher expression showed numerically poorer survival, this difference did not reach statistical significance.