Background: The expression of the L-type amino acid transporter 1 (LAT1) plays a significant role in tumor progression. However, it remains unclear whether high LAT1 expression correlates with poor prognosis of solid tumor patients. Here, we conducted a meta-analysis to assess the potential of LAT1 in predicting the prognosis of tumor patients.
Methods and findings: A total of 4,579 cases were analyzed from 35 qualified studies. In patients with solid tumors, elevated expression of LAT1 is associated with poor prognosis (overall survival [OS]: pooled hazard ratio (HR) = 1.848, 95% confidence interval (CI) = 1.620-2.108, P < 0.001; disease free survival [DFS]: pooled HR = 1.923, 95% CI = 1.585-2.333, P < 0.001; progression free survival [PFS]: pooled HR = 1.345, 95% CI = 1.133-1.597, P = 0.001). Furthermore, in subgroup analysis, we found an association between high LAT1 expression and poor OS in non-small cell lung cancer (HR = 1.554, 95% CI = 1.345-1.794, P < 0.001), pancreatic cancer (HR = 2.052, 95% CI = 1.613-2.724, P < 0.001) and biliary tract cancer (HR = 2.253, 95% CI = 1.562-3.227, P < 0.001).
Conclusion: The results of this meta-analysis indicate the reliability and potential of using LAT1 expression as a predictive biomarker in solid cancers prior to treatment. However, further studies with larger sample sizes would be beneficial for fully evaluating the predictive value of LAT1 expression for clinical applications.