High ALDH1A1 expression indicates a poor prognosis in gastric neuroendocrine carcinoma.

OBJECTIVE: To evaluate the expression and prognostic significance of ALDH1A1 in gastric neuroendocrine carcinoma. MATERIALS AND METHODS: Immunohistochemical stains of ALDH1A1 were evaluated in 67 cases of gastric neuroendocrine carcinoma. The findings were correlated with clinicopathologic variables and overall survival. RESULTS: Immunohistochemistry revealed positive cytoplasmic immunoreactivity in 35 of 67 (52.2%) tumors and strongly positive immunoreactivity in 14 of 67 (20.9%). Strongly positive ALDH1A1 expression, but not positive staining, was significantly associated with lymph node status, lymphovascular invasion, and ki-67 index (P=0.039, 0.045, and 0.045, respectively). Kaplan-Meier survival curves and log-rank tests showed significantly poorer prognoses in cases of high ALDH1A1 expression compared to cases of low ALDH1A1 expression or the negative control group (MST, 17 vs. 52 months; P=0.026). Multivariate analysis showed that high ALDH1A1 expression, lymph node metastasis, and lymphovascular invasion had significant associations with decreased overall survival (P=0.029, 0.008, and 0.005, respectively). CONCLUSIONS: High ALDH1A1 expression may be a prognostic indicator of survival in patients with gastric neuroendocrine carcinoma.