Objective: MAS related GPR family member D (MRGPRD), as a member of MAS related GPR family, was found in nociceptive neurons, muscle, hart and testicle. Moreover, high expression of MRGPRD has been observed in lung cancer. However, the relationship between MRGPRD expression and pancreatic cancer (PC) has not been reported. Hence, in this study, we evaluated MRGPRD expression in PC tissues in order to explore its clinicopatho-logical significance. Methods: This study involved 241 samples, which

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... ncluded 157 samples of PC, 66 of matched tumor-adjacent tissues and 18 of benign pancreatic lesions. Immunohistochemical staining was applied to detect the protein expression of MRGPRD and its clinical significance. Furthermore, data mining was conducted in Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) public database to confirm the clinical significance of MRGPRD. Results: The evaluation showed that 100 among 157 (63.7%) cases of PC positively expressed MRGPRD, which was significantly higher as compared to that in tumor-adjacent tissues (11/66, 16.7%) and (2/18, 11.1%) benign pancreatic lesions (both, P<0.001). More importantly, the high expression of MRGPRD was found to be related to neural invasion (r=0.362, P=0.017), clinical TNM stage (r=0.386, P<0.001) and lymph node me-tastasis (r=0.419, P<0.001) in PC. Moreover, 6% genetic alteration was noted based on TCGA database in 185 PC, including three cases of amplification, seven cases of mRNA upregulation and one case of missense mutation. Conclusion: High expression of MRGPRD might play vital roles in the neural invasion and lymph node metastasis of PC. However, this finding needs to be confirmed with larger size of patients.