Relationship Between Perineural Invasion in Prostate Needle Biopsy Specimens and Pathologic Staging After Radical Prostatectomy

BACKGROUND: Prostate cancer is the second most common malignancy among men worldwide and the sixth cause of cancer-related death. Some authors have reported a relationship between perineural invasion (PNI), Gleason score, and the invasion of peripheral organs during prostatectomy. However, it is not yet clear whether pathological evidence of PNI is necessary for risk stratification in selecting treatment type. OBJECTIVES: The clinical and pathological stages of prostate cancer are compared in patients under radical prostatectomy and in patients without perineural invasion. PATIENTS AND METHODS: This cross-sectional study was conducted using a sample of 109 patients who attended a tertiary health care center from 2008 to 2013. The selection criteria were PNI in prostate biopsy with Gleason scores less than six, seven, and eight to ten. The participants were enrolled in a census manner, and they underwent clinical staging. After radical prostatectomy, the rates of pathological staging were compared. The under-staging and over-staging rates among those with and without perineural invasion in biopsy samples were compared. RESULTS: The concordance between Gleason scores according to biopsy and pathology was 36.7% (40 subjects). The concordance rate was 46.4% and 33.3% among those with and without PNI, respectively. The concordance rates were significantly varied in different subclasses of Gleason scores in patients without PNI (P = 0.003); the highest concordance rate was a Gleason score of 7 (63.6%) and the lowest was a Gleason score of eight to ten (25%). However, there were no significant differences in patients with PNI (P > 0.05). CONCLUSIONS: Although the presence of PNI in prostate biopsy is accompanied by higher surgical stages, PNI is not an appropriate independent factor in risk stratification.