以自由型攝護腺特殊抗原的百分比預測攝護腺特殊抗原 4-20ng/ml 的攝護腺癌患者的病理期別及葛里森分數

The Use of Serum Free-to-Total Prostate Specific Antigen Ratio to Predict Pathological Stage and Gleason Grade of Prostate Cancer with PSA of 4-20 NG/ML

攝護腺癌患者血清中的free PSA的百分比呈現較低的比值是已經確定的事實，然而，目前醫學尚無法確定free/total PSA ratio（f/tPSA）和攝護腺癌的病理期別的關係，在本院施行攝護腺根除性手術的186位病患中有66位PSA值介於4.0 – 20.0 ng/ml的患者，我們嘗試由這66位病患中找出f/tPSA和病理期別的相關性。66位病患中，將其分為兩組，第一組為PSA介於4.0 – 10.0 ng/ml有36位病人，第2組為10.0-20.0ng/ml有30位病人，f/tPSA以20%作為cutoff值。（1）病理期別：於第一組，f/tPSA≦20%時，T1c+T2有12位（44.4%），而T3有15位（55.6%），在f/tPSA＞20%時則有8位（88.9%）屬於T2，有1位屬於T3（11.1%），有統計學上意義（P = 0.026）。於第二組，f/tPSA≦20%時，T2和T3各佔50％，在f/tPSA＞20%時則有3位（75％）屬於T2，有1位屬於T3（25%），則無統計學上意義（P = 0.602）。（2）Gleason grade:於第一組，f/tPSA≦20%時有8位（28%）屬於favorablepathology，有19位（72%）屬於unfavorable pathology，在f/tPSA＞20%時則有5位（56%）屬於favorable pathology，有4位（44%）屬於unfavorable pathology，無統計學上意義（P = 0.235）。第二組，也無統計學上意義（P = 1.0）。f/ tPSA ratio在PSA介於4.0 – 10.0ng/ml時，越低的ratio，其病理分期越晚期，Gleason grade在f/tPSA≦20%時，亦有增加的趨勢，但無統計學意義。對PSA＞10 ng/ml之病人，f/tPSA ratio 則無法增加預測病理結果的能力。

The value of the free/total prostate-specific antigen (f/tPSA) ratio in predicting the pathological stage and Gleason grade has remained controversial. In this study, we analyzed the relationship of the f/tPSA, prostate cancer pathological stage and Gleason grade in PSA level of 4.0–20.0 ng/ml. Total 66 patients were enrolled into this study. We divided the patients in 2 groups according to tPSA level. Group 1 was tPSA of 4.0–10.0 ng/ml, and Group 2 was tPSA of 10.0–20.0 ng/ml. The surgical specimens were examined with whole mount step section. We used the cutoff point of f/tPSA is 20%. Total and free PSA were determined using the immunoassays (Hybritech). Statistical analysis was used with Fisher exact test.As for pathological stage, in Group 1, when f/tPSA ratio > 0.2, there were 12 patients (44.4%) with organ confined disease (pT1c + pT2) and 15 patients (55.6%) with pT3 or pT4. However, when f/tPSA ratio > 0.2, whereas 8 patients (88.9%) with organ confined disease and only one patient (11.1%) with pT3. So, f/tPSA ratio as potential predictive of pathological stage when tPSA of 4.0 –10.0 ng./ml (P=0.026). In Group 2, when f/tPSA ratio > 0.2, there were 13 patients (50%) with organ confined disease and 13 patients (50%) with pT3 or pT4. likewise, when f/tPSA ratio > 0.2, whereas 3 patients (75%) with organ confined disease and one patient (25%) with pT3 (P = 0.602). As for Gleason grade, in Group 1, when f/tPSA ratio > 0.2, there were 8 patients (28%) with favorable pathology, and 19 patients (72%) with unfavorable pathology. However, when f/tPSA ratio > 0.2, whereas 5 patients (56%) with favorable pathology, and 4 patients (44%) with unfavorable pathology, the differences were not statistically significant (P = 0.235). In Group 2, there were alsoclearly no significant differences (P = 1.0). Percent free PSA significantly predicted pathological stage of prostate cancer when serum PSA levels are 4.0-10.0 ng/ml (P = 0.026). However, there was no significant relationship between f/tPSA and pathological features in serum PSA of 10.0-20.0 ng/ml and Gleason grade in this study.