ALP、PSA及其相关指标与前列腺癌骨转移的关系

目的探讨ALP、PSA及其相关指标（fPSA、fPSA/tPSA、PSAD）与前列腺癌骨转移的关系,及对前列腺癌骨转移诊断的预测作用。方法回顾分析2005年9月至2009年2月在我院经前列腺穿刺活检或手术后病理检查确诊的167例前列腺癌患者。以ECT、X线片、CT/MRI或骨活检诊断骨转移,分析ALP、PSA、fPSA、fPSA/tPSA、PSAD与前列腺癌骨转移的关系及对骨转移的诊断价值。结果 167例前列腺癌患者中骨转移104例（62.3%）,非骨转移63例（37.7%）。骨转移组ALP、PSA及PSAD明显高于非骨转移组（均P〈0.01）,而两组间fPSA/tPSA差异无统计学意义（P〉0.05）。PSA〉50ng/ml组骨转移率明显高于PSA〉20～50ng/ml组、〉10～20ng/ml组和≤10ng/ml组（均P〈0.05）;ALP〉90U/L组骨转移率明显高于ALP≤90U/L组（P〈0.05）;PSAD〉0.4ng.ml-1.cm-3组骨转移率明显高于PSAD≤0.4ng.ml-1.cm-3组（P〈0.05）。以ALP〉90U/L、PSA〉50ng/ml和PSAD〉0.4ng.ml-1.cm-3为界分别分析ALP、PSA、PSAD、PSA＋ALP、PSA＋PSAD和PSA＋PSAD＋ALP对前列腺癌骨转移诊断的预测价值,发现指标联合应用后阳性预测值及阴性预测值较单一指标好,PSA＋PSAD＋ALP联合应用的敏感度、特异度、阳性预测值及阴性预测值最佳,分别为100%、79.17%、91.38%及100%。结论 ALP、PSA及PSAD均为判断前列腺癌患者有无骨转移的可靠指标,PSA＋PSAD＋ALP联合应用有助于预测前列腺癌骨转移,当患者PSA〈50ng/ml、PSAD〈0.4ng.ml-1.cm-3及ALP〈90U/L时,几乎可排除骨转移。

Relationship between ALP、PSA、PSA-based parameters and bone metastasis in PCa

Objective To investigate the relationships between ALP、PSA、PSAD （PSA density） and free-to-total PSA （fPSA/tPSA） ratio and osseous metastasis in prostate cancer patients,and the role of these parameters in the prediction of osseous metastasis in prostate cancer.Methods A total of 167 patients with histologically diagnosed prostate cancer in our hospital from Sep.2005 to Feb.2009 were analysed.Serum PSA levels were measured using the ROCHE Modular Analytics E170 automatic electrochemiluminescence immunoassay.Volume of prostate was estimated by abdominal ultrasound measurements using the prostate ellipse formula （0.52×length×width×height）.PSAD （PSA/volume） was calculated by dividing serum PSA level by volume of prostate.ECT,CT/MRI and bone biopsy were used for diagnosis of osseous metastasis.Results Of 167 consecutive patients,104 had osseous metastasis （62.3%）.ALP,PSA,fPSA and PSAD in osseous metastasis group were higher than non-osseous metastasis group,respectively （P0.01）,no significant difference existed for fPSA/tPSA between osseous metastasis group and non-osseous metastasis group （P0.05）.Osseous metastasis positive rate：PSA levels of 50 ng/ml was higher than levels of 20-50 ng/ml,10-20 ng/ml and ≤10 ng/ml（P0.05）; ALP levels of 90 U/L was higher than levels of ≤90 U/L （P0.05）; PSAD0.4 ng·ml-1·cm-3 was higher than PSAD≤0.4 ng·ml-1·cm-3（P0.05）.Sensitivity,specificity,positive predictive value and negative predictive value：ALP cut-off of 90 U/L were 55.77%,74.60%,78.38% and 50.54%,respectively; PSA cut-off of 50 ng/ml were 85.58%,77.78%,86.41% and 76.56%,respectively; PSAD cut-off of 0.4 ng·ml-1·cm-3 were 97.12%,38.10%,72.14% and 88.89%,respectively.PSAD cut-off of 0.4 ng·ml-1·cm-3 combined with PSA cut-off of 50 ng/ml and ALP cut-off of 90 U/L were showed the best sum of sensitivity,specificity,positive predictive value and negative predictive value,which were 100%,79.17%,91.38% and 100%,respectively.Conclusion s ALP,PSA and PSAD are valuable parameters used in prediction of osseous metastasis in prostate cancer.Although further studies are needed to determine optimal cut-off value to be used in clinical practice,PSAD cut-off of 0.4 ng·ml-1·cm-3 combined with PSA cut-off of 50 ng/ml and ALP cut-off of 90 U/L seems to be useful for the prediction of osseous metastasis in prostate cancer patients.This would be justified its utility in clinical practice reducing unnecessary ECT and CT/MRI examinations,which are relatively expensive and harmful.