BACKGROUND Tropomyosin alpha-1 chain (TPM1) is a member of the tropomyosin family and the expression of TPM1 is found to be dysregulated in various tumors. The present study aimed to investigate the clinical performance and significance of TPM1 in gastric cancer. METHODS First, the levels of TPM1 mRNA and protein were detected through real-time polymerase chain reaction (RT-qPCR) and immunohistochemistry (IHC) respectively. The correlation between TPM1 expression and clinicopathological variables was analyzed. Then, receiver operating characteristic (ROC) curve was applied to determine the diagnostic performance of TPM1 in gastric cancer. Finally, overall survival analysis was carried out using Kaplan-Meier method in order to determine the prognostic performance of TPM1 in gastric cancer. RESULTS Compared with the controls, TPM1 mRNA and protein expression levels were significantly downregulated in patients with gastric cancer. Downregulation of TPM1 was associated with depth of invasion and tumor node metastasis (TNM; p = 0.0030 and 0.0175, respectively). Furthermore, TPM1 might be a novel predictive biomarker for gastric cancer with an area under curve (AUC) of 0.8327. Overall survival analysis indicated that low TPM1 expression predicted poor survival (log-rank test, p = 0.0058). CONCLUSIONS TPM1 might be a novel predictive diagnostic and prognostic biomarker for gastric cancer (95% con-fidence interval = 0.7705 - 0.8949, p < 0.0001).
