Abstract
Gastric cancer (GC) is one of the most common malignant tumors worldwide. Previous studies have reported that aldehyde dehydrogenase-1A1 (ALDH1A1) and cluster of differentiation (CD)-133 are considered to be cancer stem cell markers in GCs. The present study immunohistochemically examined the distribution and expression of two tumor stem cell markers, CD133 and ALDH1A1, in both primary tumors and para-tumor tissues. In 91 cases with stage III, 57 (62%) were positive for ALDH1A1 and 60 (66%) were positive for CD133. ALDH1A1 was detected in para-tumors and cancerous tissues of the stomach, and the immunoreactivity of the tumors was stronger than that in para-tumor tissues. CD133 was only detected in tumors. The expression of ALDH1A1 was significantly associated with advanced T/N stage (T stage, P=0.012; N stage, P=0.023) and poor differentiation (P=0.020), while CD133 was associated with advanced T stage (P=0.007). Univariate and multivariate Cox proportional hazards analysis revealed that tumor stage, CD133 expression, vascular invasion and sex were independent predictors of disease-free survival (DFS) time, and tumor size, vascular invasion and sex were independent predictors of overall survival (OS) time in patients with GC. Patients with CD133+ GC had poorer DFS (P=0.042), while ALDH1A1+ GC was not associated with poorer DFS. In regard to chemotherapy, improvements in survival were not observed after the addition of taxane compared with two-drug therapy. However, the subgroup analysis indicated that in the ALDH1A1- subgroup, and CD133+ and ALDH1A1- subgroups, an increased OS was observed in two-drug therapy (P=0.043). The results of the present study indicate that ALDH1A1 and CD133 may play an important role in tumor invasion, metastasis and prognosis, and ALDH1A1- expression does not benefit the taxane-based triple chemotherapeutic regimen in patients with GC.