Evaluation of serum level of substance P and tissue distribution of NK-1 receptor in endometrial cancer

Substance P (SP), a neuropeptide belonging to the tachykinin family, exerts different biological activities mainly through neurokinin-1 receptor (NK1R). The role of SP/NK1R system in tumoral growth and spread is reported in several cancers. We aimed to evaluate the serum SP concentration and NK1R tissue distribution in endometrial cancer, and to study the relationship between these factors with tumor size, lymph node involvement, disease stage and cancer grade. Recruiting 22 patients with endometrial cancer and 21 patients with leiomyoma as the control group, serum SP concentration was measured using an ELISA method, and NK1R tissue distributions were immunohistochemically analyzed. Serum SP concentration in patients was significantly higher than the control group (p-value = 0.005). The expression level of NK1R in tumoral tissue was more than normal tissue (p-value < 0.001). The NK1R expression had a significant relationship with lymph node involvement (p-value = 0.005) and disease stage (p-value = 0.017). The NK1R expression was higher in more advanced and less-differentiated tumors. SP/NK1R system seems to play a role in tumor growth and development in endometrial cancer. As well, the NK1R expression increased in endometrial cancer, and may be considered as a prognostic factor; but further studies are needed in this field.