DKK-1 in prostate cancer diagnosis and follow up

BACKGROUND Dickoppf-1 (DKK-1) is a negative regulator of bone formation with tumorigenic potential. The up-regulation of DKK-1 is an early event in prostate cancer (PCa) development, thus we investigated its role as a marker in the diagnosis and prognosis of PCa. METHODS We retrospectively enrolled 159 patients who underwent prostate biopsy, either for elevated PSA or suspect digital rectal examination, between 2003 and 2010. During the biopsy, one serum sample was collected from all patients; PSA and DKK-1 were measured by ELISA technique. Amongst the biopsy of 159 patients 75 were affected by PCa and 84 were not the mean period of follow-up for these patients was 5 years; a new biopsy was performed in case of PCa suspicion. RESULTS PSA performed better than DKK-1 in detecting PCa (0.63 vs 0.51 respectively). Differently from PSA DKK-1 was significantly higher in patients who developed PCa during follow-up than in cancer-free ones, thus DKK-1 performed better than PSA in detecting these patients (0.67 vs 0.55). DKK-1 was significantly lower in patients with bone metastases, whereas PSA was not significantly different in patients with different outcomes. CONCLUSIONS DKK-1 might be predictive for patients negative at first biopsy who will develop PCa and in the prognosis of bone metastases. It performed worse than PSA in the early diagnosis of Pca.