An exploratory determination of new bone markers in natural history of prostate cancer (PC) patients.

Abstract

e15121 Background: PC is one of the most expanded oncologic diseases worldwide. Currently, PSA is the only biological marker able to follow PC natural history. We investigated serum and urinary bone markers (BM) that may earlier define PC evolution either in hormone naive or not and free-bone metastatic pts or not. Methods: 40 PC pts distributed in 4 groups were studied as follow: A, Non castration-refractory patients (NCRP) without distant mets; B, NCRP with distant mets; C, Castration-refractory patients (CRP) without distant mets; D, CRP with distant mets. Serum BM investigated were osteogenesis-related (Osteocalcin, procollagen amino-terminal propeptide 1 {P1NP}, bone alkaline phosphatase) and osteolysis-related (collagen carboxyterminal peptide {CTX}, carboxyterminaltelopeptide type 1 collagen {1CTP}, tartrate resistant acid phosphatase {TRAP}, osteoprotegerin, receptor/activator of nuclear factor KB ligand {RANKL}). Other markers were albumin, creatinine, parathyroid hormone, total calcium and 25- OH vitamin D3. Urinary BM studied were crosslaps and creatinine. Results: Most significant markers (univariate) were used for logistic/discriminant analysis. The most contributing markers differentiating the following strata were: (1) A vs B vs C vs D : 1CTP, creatinine, P1NP, TRAP and albumine; (2) BD vs AC: P1NP, 1CTP and RANKL (ROC: AUC=0.85); (3) AB vs CD: albumine, 1CTP, P1NP and TRAP (ROC: AUC=0.88); (4) A vs C : serum and urinary creatinine, TRAP, CTX and urinary crosslaps levels (ROC: AUC=0.98). Conclusions: New BM were investigated and P1NP seems to be a relevant marker to follow natural history of PC. P1NP could be useful to predict bone metastasis evolution and a longitudinal study is under investigation. Given the small sample used in this analysis, results should be received with caution. No significant financial relationships to disclose.