High Nr-CAM expression is associated with favorable phenotype and late PSA recurrence in prostate cancer treated by prostatectomy

BACKGROUND: Neuron-glia-related cell-adhesion molecule (Nr-CAM) is another potential membrane-bound target molecule for specific prostate cancer therapy. The role of Nr-CAM in normal and neoplastic prostate tissue has not been extensively studied. The aim of our study is to evaluate the prevalence of Nr-CAM expression in prostate cancer and to explore its association with phenotype and clinical disease course.

METHODS: A preexisting tissue microarray including more than 3000 prostate cancers that underwent prostatectomy at our center with clinical follow-up data was used. The tissue microarray (TMA) was immunhistochemically stained for Nr-CAM.

RESULTS: A total of 2883 (88.4%) of tumor samples were interpretable in our TMA analysis. Membranous Nr-CAM staining was seen in 1418 (49.2%) of 2883 analyzable cases. According to predefined criteria, staining was considered weak in 778 (27.0%), moderate in 412 (14.3%) and strong in 228 (7.9%) cancers. Significant associations were found with pathological tumor stage (P=0.0015), Gleason grade (P=0.0003), nodal stage (P=0.0061), preoperative PSA (P=0.0138) and prolonged PSA recurrence-free survival (P<0.0001).

CONCLUSIONS: Nr-CAM expression is frequent in prostate cancer. High level of Nr-CAM expression is associated with favorable tumor phenotype and reduced risk of PSA recurrence. The abundant presence of Nr-CAM in prostate cancer epithelium makes Nr-CAM a potential target of therapy.