RESUMEN
Objective:To investigate the relationship between the serum alkaline phosphatase (ALP), prostate specific antigen (PSA) and bone metastasis in initially diagnosed prostate cancer (PCa) patients in different ISUP(International Society of Urological Pathology)groups.Methods:The 368 initial diagnosed prostate cancer patients recruited from January 2013 to December 2018 were retrospectively analyzed, including 247 cases in the Third Affiliated Hospital of Sun Yat-sen University, 111 cases in the Yuebei People's Hospital Affiliated to Medical College of Shantou University and 10 cases in Shenzhen Hospital of Southern Medical University. According to whether there was bone metastasis at the initial diagnosis, it was divided into 230 cases in the bone metastasis group and 138 cases in the non bone metastasis group. There was no significant difference between the two groups in age [(71.9±9.4) years and (71.2±8.7) years], body mass index (BMI) [(23.1±3.7) kg/m 2 and (23.7±2.6) kg/m 2]. There were significant differences in PSA [(307.3±847.0) ng/ml and (84.5±257.3) ng/ml] and ALP [(174.5±270.8) U/L and (71.0±23.2) U/L] between the two groups. In different PSA subgroups, there were 45 cases in PSA <10 ng/ml, 35 cases in PSA 10-20 ng/ml and 288 cases in PSA >20 ng/ml. The differences of ALP and PSA between bone metastasis group and non-bone metastasis group based on different ISUP stratification were analyzed, ROC curves were used to predict their risks of bone metastasis. Results:There were 3(1.3%), 22(9.6%), 34(14.8%), 85(37.0%) and 86 (37.4%) prostate cancer patients with bone metastasis from ISUP group 1 to 5, and 14(10.1%), 19(13.8%), 29(21.0%), 32(23.2%) and 44(31.9%) without bone metastasis, respectively. There was significant difference in the serum ALP levels between the bone metastasis group and the boneless metastasis group in the ISUP group 4(157.6±207.7 vs. 66.5±17.0) and 5(189.4±257.5 vs. 69.2±18.4)( P<0.001) and PSA levels had difference in the ISUP group 3(240.3±313.0 vs. 42.4±42.1), 4(152.3±184.5 vs. 44.7±33.3) and 5(435.2±1006.3 vs. 60.8±84.8)( P<0.001). There was statistically significant between the bone metastasis group and the without(336.1±882.2 vs. 139.3±328.1) when PSA>20 ng/ml( P=0.006). ROC curve analysis: the cut-off values of ALP were 115.5, 109.0, 75.5 and 86.0 U/L from ISUP group 2 to 5 respectively, the sensitivity was 23.8%, 56.5%, 66.4% and 50.6% respectively, the specificity was 99.7%, 93.4%, 78.3% and 89.2% respectively, and the accuracy were 59.4%, 73.1%, 69.7% and 63.3%, respectively. The cut-off values of PSA were 39.5, 93.1, 54.2 and 28.9 ng/ml from ISUP group 2 to 5 respectively, the sensitivity was 64.4%, 68.4%, 87.4% and 88.3% respectively, and the specificity was 79.5%, 90.6%, 63.7% and 61.6% respectively, and the accuracy were 71.6%, 78.1%, 80.1% and 79.2%, respectively. Conclusion:ALP increased significantly in ISUP group ≥4 and PSA in ISUP group ≥3, which related to bone metastasis in patients with initial diagnosed prostate cancer.