Clinical characteristics and risk factors for prostate cancer with PSA≤20 ng/mL: a multicenter study

Abstract:

Objective To explore the clinical characteristics of bone metastasis and its correlation with clinicopathological factors in patients with prostate cancer with prostate specific antigen（PSA） ≤20 ng/mL.Methods This study retrospectively analyzed the clinical and pathological data of patients who were newly diagnosed with prostate cancer with PSA ≤20 ng/mL in Nanfang Hospital，Zhujiang Hospital，and General Hospital of Southern Theater Command from January 2011 to December 2017. The patients were divided into two groups according to with or without bone metastasis. Differences in age，PSA，complexed PSA（cPSA），free PSA（fPSA），Gleason score（GS），and T and N stages were analyzed between the two groups，and the correlation of these factors with bone metastasis was analyzed. A further subgroup analysis was performed based on PSA levels（≤10 ng/mL and 10.01-20 ng/mL），GS（GS ≤ 6 and GS ≥ 7），T stages（T_1-2 and T_3-4），and N stages（N₀ and N₁） to explore the characteristics of bone metastasis between subgroups. Finally，univariate and multivariate logistic regression analyses were used to identify risk factors for bone metastasis.Results Of all 237 patients involved in this study，42（17.7%） patients showed bone metastases，and the incidence rates of bone metastasis in patients with PSA <4 ng/mL，patients with PSA≤10 ng/mL，and patients with PSA of 10.01-20 ng/mL were 7.5%，12.1%，and 24.8%，respectively. There were significant differences in PSA，cPSA，and fPSA levels，GS，and T and N stages between the patients with and without bone metastasis（P<0.05）. There was no significant difference in age between the two groups（P>0.05）. The subgroup analysis further revealed that with the increases in PSA level and GS，the incidence of bone metastasis was consistently increased，and bone metastasis was more frequent in patients with stage T_3-4 and N₁ disease ［odds ratio（OR）=2.372，95%CI=1.148-4.901，P=0.020；OR=6.458，95%CI=2.435-17.131，P<0.001］. logistic regression analyses showed that PSA level，GS，and T and N stages were closely related to bone metastasis in patients with prostate cancer with PSA ≤20 ng/mL，and PSA level，GS，and N stage were independent risk factors for bone metastasis（P<0.05）. There was no significant association between age and bone metastasis（P>0.05）.Conclusion More tumor aggressiveness is found in patients with GS ≥7 and stage T_3-4 and N₁ disease among patients with prostate cancer with PSA ≤20 ng/mL. PSA level，GS，and N stage are independent risk factors for bone metastasis in patients with prostate cancer with PSA ≤20 ng/mL.