On the other hand, in multivariate analysis, patients with higher NPY immunostaining had a higher risk of PSA relapse after prostatectomy than those with low NPY patients (Rasiah et al. 2006), while another study reported increased mortality among PCa patients with high pro-NPY (Iglesias-Gato et al. 2016). Our study did not find any significant correlations between the NPY system and tumour stage, grade, patient age and proliferation index. Here, NPY is linked to neoplasm.