前列腺癌尿液肿瘤标志物的研究进展

前列腺癌是男性生殖系统最常见的恶性肿瘤之一,也是导致男性癌症死亡的第五大原因,早期诊治可改善患者预后。目前,前列腺癌的诊断主要依赖于直肠指诊或血清前列腺特异性抗原(prostate specific antigen,PSA)检测后前列腺穿刺活检确诊。但血清PSA检测特异性较低,不能有效区分惰性前列腺癌与具有临床意义的前列腺癌,导致不必要的活检及过度治疗,因此迫切需要更具特异性的肿瘤标志物。前列腺癌细胞可将肿瘤标志物释放至前列腺液中,而后进入尿液,因此通过尿液即可检测前列腺癌肿瘤标志物。近年来,已开发了多种基于尿液及其外泌体的肿瘤标志物,如PSA、PCA3、MALAT1及微RNA等,本文将阐述尿液肿瘤标志物在前列腺癌诊断中的研究进展。     

Lectin and serum-PSA interaction as a screening test for prostate cancer

OBJECTIVES: The present investigation was designed to distinguish prostate cancer and benign prostate hyperplasia by lectin-prostate specific antigen (PSA) binding. DESIGN AND METHODS: The quantitative precipitin method of concanavalin A (Con A)-carbohydrate interaction was explored with the serum PSA of patients suffering from prostatic complications. RESULTS: The carbohydrate content in the precipitate after binding of Con A with serum PSA of prostate cancer was significantly lower than that of benign prostate hyperplasia. This may be due to altered sugar chain structure or less glycosylation of PSA in prostate cancer. CONCLUSIONS: We conclude that a serum value <3.0 microg/ml of the carbohydrate content of Con A-PSA precipitate indicates strong suspicion for prostate cancer and this cut off level is effective in reducing the rate of unnecessary biopsies in men with total PSA value between 4.0 to 10.0 ng/ml.     

Clinical use of novel urine and blood based prostate cancer biomarkers: A review

In the era of upcoming techniques for molecular profiling, breakthroughs led to new discoveries in the field of prostate cancer (PCa) biomarkers. Since the early 1990s a tremendous increase in PCa incidence is seen, dedicated to the introduction of prostate specific antigen (PSA) testing. However, due to its lack of specificity many men undergo unnecessary biopsies, resulting in a rising incidence of clinically insignificant PCa. To overcome this drawback, cancer specific biomarkers are needed to identify patients who are at high risk of harbouring PCa and to distinguish patients with aggressive disease from patients with insignificant cancer. The most non-invasive, easy to obtain substrate for biomarker measurement is urine. The most promising markers to date are PCA3 and TMPRSS2–ERG. Both markers demonstrate to have a higher specificity and diagnostic accuracy for PCa outcome compared to serum PSA. This might better predict the presence of PCa and therefore reduce the number of unnecessary biopsies. Combining both markers in a panel might result in an even higher diagnostic accuracy, given the heterogeneity of the disease. In PCa management, circulating tumour cells (CTCs) detected in the blood seem a promising tool to predict treatment response and survival benefit. Although results appear to be encouraging, the biggest challenge about new markers in PCa is to validate them in large clinical trials and subsequently implement these markers into clinical practice. In this review we discuss the clinical usefulness of novel, non-invasive tests in PCa management.     

Values for free/total prostate-specific antigen ratio as a function of age: necessity of reference validation in a Turkish population.

BACKGROUND: The aim of this study was to evaluate age-related changes in free/total prostate-specific antigen (f/t PSA) ratio, focusing on the avoidance of unnecessary prostate biopsies. METHODS: A total of 898 men aged 30-88 years without a history of prostate surgery and disease were enrolled into the study. Serum tPSA, fPSA and f/t PSA ratios were determined for the study population and for different age categories. All males who had suspicious digital rectal examination and tPSA >4 ng/mL underwent transrectal ultrasonography-guided prostate biopsy. Receiver operating characteristic (ROC) curves for each group were generated by plotting the sensitivity vs. 1-specificity for the f/t PSA ratio. The sensitivity and specificity were obtained using different f/t PSA ratio cutoffs for different age groups. RESULTS: Prostate cancer was detected in 63 patients (7%). Age-specific cutoffs were determined according to likelihood ratios at the levels of 10%, 15% and 15% f/t PSA ratio for ages 50-59, 60-69 and >/=70 years, respectively. However, a single cutoff of 10% is recommended across all age ranges (positive likelihood ratio 2.36). ROC curves demonstrated that the area under the curve (AUC) was significant for all patients with initial PSA of 4-10 ng/mL (AUC 0.703-0.796), except for the >/=70-year age group (AUC 0.549). CONCLUSIONS: The current study showed that the use of f/t PSA ratio in patients with PSA levels of 4-10 ng/mL should enhance the specificity of PSA screening and decrease the number of unnecessary biopsies. f/t PSA levels may show dissimilarities according to age and ethnicity, so further studies are warranted to identify this relationship.     

Prostate-specific antigen ratio correlates with aggressiveness of histology grades of prostate cancer

OBJECTIVES: To compare prostate-specific antigen (PSA) ratio to total PSA (tPSA) assay for prostate cancer diagnosis and to study the correlation of PSA ratio with histology grade of prostate cancer. METHODS: Among 334 selected cases, 136 had benign prostate diseases and 198 had prostate cancer. All cases underwent transrectal ultrasound (TRUS) and tissue biopsies within 6 months of their tPSA measurements. All of the tPSA levels taken were between 2 and 20 microg/L. The serum tPSA and free PSA were assayed using the Abbott AxSYM immunoassay system (Abbott Laboratories; Abbott Park, IL, USA). The PSA ratios of patients with prostate cancer were compared to those with benign prostate diseases (BPD) using the Student's t test. Correlation between the histology grades and PSA ratios was calculated by Pearson test. Receiver operating characteristic (ROC) curves were generated from sensitivities and specificity of various PSA ratios and tPSA levels. RESULTS: We found an inverse correlation between PSA ratios and aggressiveness of histology grades (r = -0.995, p < 0.01). The higher the histology grade, the lower the PSA ratio tended to be, and the more sensitive and specific the PSA ratio was in the diagnosis of prostate cancer. No correlation was found between histology grades and tPSA levels. A PSA ratio of 0.25 diagnosed 93% of patients with Gleason score greater than 7 and 83% of all prostate cancer patients. It would have reduced unnecessary biopsies by 23% compared to the tPSA level of 4 microg/L. Sensitivity of PSA ratios was higher and specificity was lower in high tPSA level group than they were in low tPSA level group. CONCLUSIONS: PSA ratio inversely correlates to aggressiveness of prostate cancer and has a potential to predict histology grade of prostate cancer. PSA ratio improves sensitivity and specificity for prostate cancer diagnosis compared to tPSA assay.     

Prostate Cancer in Primary Care

Prostate cancer is a common malignancy seen worldwide. The incidence has risen in recent decades, mainly fuelled by more widespread use of prostate-specific antigen (PSA) testing, although prostate cancer mortality rates have remained relatively static over that time period. A man’s risk of prostate cancer is affected by his age and family history of the disease. Men with prostate cancer generally present symptomatically in primary care settings, although some diagnoses are made in asymptomatic men undergoing opportunistic PSA screening. Symptoms traditionally thought to correlate with prostate cancer include lower urinary tract symptoms (LUTS), such as nocturia and poor urinary stream, erectile dysfunction and visible haematuria. However, there is significant crossover in symptoms between prostate cancer and benign conditions affecting the prostate such as benign prostatic hypertrophy (BPH) and prostatitis, making it very challenging to distinguish between them on the basis of symptoms. The evidence for the performance of PSA in asymptomatic and symptomatic men for the diagnosis of prostate cancer is equivocal. PSA is subject to false positive and false negative results, affecting its clinical utility as a standalone test. Clinicians need to counsel men about the risks and benefits of PSA testing to inform their decision-making. Digital rectal examination (DRE) by primary care clinicians has some evidence to show discrimination between benign and malignant conditions affecting the prostate. Patients referred to secondary care for diagnostic testing for prostate cancer will typically undergo a transrectal or transperineal biopsy, where a number of samples are taken and sent for histological examination. These biopsies are invasive procedures with side effects and a risk of infection and sepsis, and alternative tests such as multiparametric magnetic resonance imaging (mpMRI) are currently being trialled for their accuracy and safety in diagnosing clinically significant prostate cancer.     

Applicability of biomarkers in the early diagnosis of prostate cancer

Early diagnosis of prostate cancer can increase the curative success rate for this disease. Although serum prostate-specific antigen measurement is regarded as the best conventional tumor marker available, there is little doubt that it has great limitations. The threshold above which biopsies are indicated has now decreased to a serum prostate-specific antigen value of 3 ng/ml, which results in a negative biopsy rate of 70-80%. This can readily be explained by the fact that prostate-specific antigen is not specific for prostate cancer. Clinicians need more sensitive tools to help diagnose prostate cancer and monitor progression of the disease. Molecular oncology is playing an increasing role in the fields of diagnosis and therapy for prostate cancer and has already been instrumental in elucidating many of the basic mechanisms underlying the development and progression of this disease. The identification of new prostate cancer-specific genes, such as DD3PCA3, would represent a considerable advance in the improvement of diagnostic tests for prostate cancer. This could subsequently lead to a reduction of the number of unnecessary biopsies.     

Prostate-specific antigen in screening of prostate cancer

Prostate-specific antigen (PSA) is a wellcharacterized human prostate-specific glycoprotein. PSA has been shown to be the most effective immunohistologic marker for prostate cancer, as well as the most useful serologic test in staging and monitoring prostate cancer and in early detection of recurrent disease. The greatest clinical value of PSA is as an aid for early detection of prostate cancer. Recent studies have indicated that PSA-based screening of the older population for organ-confined early-stage prostate cancer is an acceptable, practical, and reliable modality. The accuracy of PSA screening is within the same range as the mammogram. The cost-effectiveness of PSA is comparable to other cancer screening tests. Although the increase in the patient's survival due to PSA-based detection of early prostate cancer remains to be documented, it is generally agreed that the PSA test along with digital rectal examination (DRE) should be included in the annual physical examination for men 50 years of age or older. Highrisk men are urged to commence at age 40. Asymptomatic men who have both a negative DRE and normal PSA blood test need only to continue an annual DRE and PSA check-up. Men who have a negative DRE and elevated PSA, and all those who have a suspicious DRE regardless of PSA results, should undergo further diagnostic workup, such as transrectal ultrasonography with biopsy of visible lesions. The cure rate is high with timely treatment, when prostate cancer is detected while still confined to the prostate. © 1994 Wiley-Liss, Inc.     

Specificity and accuracy of TRUS-measured PSA-density and transition zone-PSA in the diagnosis of prostate cancer

Between 4 and 15 ng/ml serum prostate-specific antigen (PSA) has a low specificity for prostate cancer (PCa). One accepted method to enhance this specificity is transrectal ultrasonography (TRUS)-measured PSA-density (PSA-D). We compared this method with a new alternative, transition zone PSA (PSA-TZ). We measured total and transition zone prostatic volumes by TRUS and calculated PSA-D and PSA-TZ in 59 patients with suspicion of PCa and PSA between 4 and 15 ng/ml. All patients then had sextant biopsies of the prostate, 30 were positive for PCa and 29 showed benign tissue. With a cut-off value of 0.35, PSA-TZ had a positive predicted value of 77% for PCa, whereas PSA-D, with a cut-off value of 0.12, had a positive predicted value of 55%. Our data suggest PSA-TZ to be more reliable for avoiding unnecessary biopsies in patients with PCa suspicion and serum PSA below 15 ng/ml. PSA-TZ, calculated by TRUS, enhances the specificity of PSA for needle biopsy diagnosis of PCa.     

Focal prostatic atrophy: mimicry of prostatic cancer on TRUS and 3D-MRSI studies

Prostatic atrophy which represents a form of adaptive response to injury most commonly to inflammation and/or chronic ischemia is a histological abnormality frequently found in prostate biopsies and autopsies. Although commonly found, this lesion is rarely reported in the prostatic biopsy reports. It is well known that histologically focal prostatic atrophy (FPA) is one of the most frequent mimics of prostatic adenocarcinoma. On conventional and color Doppler transrectal ultrasound and on magnetic resonance spectroscopic imaging studies (MRSI), FPA may also simulate prostate cancer. Thus, this entity should be considered together with prostatitis as an important cause of false-positive results in MRSI of the prostate. It has been shown that there is a positive and significant association between extent of FPA in biopsies and serum total or free PSA elevation. For this reason, pathologists should include the presence of FPA in the pathology report of a prostatic biopsy, particularly in those patients with absence of cancer. When extensive FPA is the only finding in patients with several negative prostatic biopsies, this lesion may be the source for PSA elevation.     

PSAD、F／T在tPSA低水平异常的前列腺癌诊断价值

目的：比较前列腺特异性抗原密度（PSAD）、游离PSA （fPSA）与总PSA （tPSA）比值（F/T）在tPSA 4～10、10～20μg/L水平的前列腺癌诊断价值。方法选取tPSA 4～20μg/L、经直肠B超前列腺穿刺活组织检查（活检）的449例患者,对PSAD、F/T和前列腺活检结果的关系进行研究。结果449例中前列腺癌78例（17.4％）,tPSA 4～10、10～20μg/L 阳性率分别为10.4％、23.1％（P＜0.001）,F/T和PSAD在穿刺前列腺癌组和非前列腺癌组间比较差异均有统计学意义（P＜0.01）,受试者工作特征曲线下面积（AUC） PSAD＞F/T＞tPSA,PSAD与tPSA间AUC比较差异有统计学意义（P＜0.01）,F/T和tPSA间AUC比较差异无统计学意义。当诊断敏感度为100％时,在PSA 4～10、10～20μg/L水平,PSAD特异度分别为5.0％和2.1％,可分别避免不必要前列腺穿刺4.9％和2.4％。结论在PSA 4～20μg/L水平上,PSAD和F/T对预测是否行前列腺穿刺有帮助,在诊断敏感度和特异度上,PSAD优于F/T。     

Prostate-specific antigen and prostate volume: A meta-analysis of prostate cancer screening criteria

Objective: To establish the value of serum prostate-specific antigen (PSA) and prostatespecific antigen per unit volume of prostate gland (PSAD) in detecting prostate carcinoma (CaP) in a hypothetical screening algorithm, a meta-analysis of the sensitivities, specificities, predictive values and likelihood ratios were combined from the published data. Data Sources: Journal articles identified by a MEDLINE database search from 1988 to October 1992, using prostate-specific antigen as a key word were used to calculate the distribution of PSA in healthy men, men with benign prostatic hyperplasia (BPH) and men with prostate carcinoma (CaP) Study Selection: Only studies that contained the specified serum PSA values and patient outcomes were included. Data Extraction: The distributions of the serum PSA were plotted versus serum PSA for healthy men (2567), men with BPH (798) and men with CaP (835) from the abstracted data. Prostate volume distributions were estimated from the published transrectal ultrasound (TRUS) calculations. Data Synthesis: Hypothetical cohorts of 1,000 men between the ages of 60 and 70 years were screened using three different screening decision algorithms. Using a serum PSA cutoff of 3.0 ng/ml for referral for transrectal biopsy, 59 of 80 (74%) CaP would be detected and 21 (26%) would be missed. 209 transrectal biopsies would be performed, and 150 (72%) of them would be negative for CaP. Using a serum PSA cutoff of 4.0 ng/ml, 52 of 80 (65%) CaP would be detected and 28 (35%) would be missed. 146 transrectal biopsies would be performed, and 94 (64%) of them would be unnecessary. Using a cutoff of 2.0 ng/ml for serum PSA and 0.1 ng/ml/cc for PSAD, 55 of 80 (69%) of the cancers would be detected and 25 (31%) would be missed. Only 84 transrectal biopsies would be performed, and 29 (35%) of them would be negative for cancer. Conclusion: This algorithm maximizes the number of cancers detected (true-positive cases) and at the same time reduces the number of false-positive cases, minimizing the number of patients who would have to receive an unnecessary transrectal biopsy, compared to using a serum PSA cutoff of 3.0 or 4.0 ng/ml. © 1993 Wiley-Liss, Inc.     

Prostatic carcinoma. Screening--when and what?

Prostate cancer is now the most common cancer and the second most common cause of death from cancer among men. Therapy of curative intention is only possible in organ confined disease. The use of prostate specific antigen (PSA) and digital rectal examination (DRE) results in a three fold increase in prostatic carcinoma detection. Levels of PSA > 4 ng/ml are indications for sextant biopsies of the prostate. There did not exist an intermediate range or 'grey zone' of PSA 4-10 ng/ml where wait and see diagnostic procedure is indicated. In PSA levels > 10 ng/ml curative therapy can only performed in 15-44% of the cases. PSA and DRE examination should be performed between the age of 50 and 70 years when life expectancy exceeds ten years. In case of familiar history the case finding has to start at the age of 45. There is no support for the common opinion that early detection finds clinically insignificant cancer since autoptical prevalence of prostate cancer is about 40% and early detection discover only 3-4%. Results about the usefulness of active screening in a population will be available in 2005.     

Antiangiogenic properties of prostate‐specific antigen (PSA)

The prostate produces high levels of prostate‐specific antigen (PSA, also known as kallikrein‐related peptidase 3, KLK3), which is a potential target for tumor imaging and treatment. Although serum PSA levels are elevated in prostate cancer, PSA expression is lower in malignant than in normal prostatic epithelium and it is further reduced in poorly differentiated tumors. PSA has been shown to inhibit angiogenesis both in in vitro and in vivo models. In this review we focus on our recent studies concerning the mechanism of the antiangiogenic function of PSA. We have recently shown that the antiangiogenic activity of PSA is related to its enzymatic activity. Inactive PSA isoforms do not have antiangiogenic activity as studied by a human umblical vein endothelial cell (HUVEC) tube formation model. Furthermore, inhibition of PSA, either by a monoclonal antibody or small molecule inhibitors abolishes the effect of PSA, while a peptide that stimulates the activity of PSA enhaces the antiangiogenic effect. We have analyzed changes in gene expression associated with the PSAinduced reduction of tube formation in the HUVEC model. Several small changes were observed and they were found to be opposite to those associated with tube formation. Taken together, these studies suggest that PSA exerts antiantiogenic activity related to its enzymatic activity. Thus it might be associated with the slow growth of prostate cancer.     

Clinical efficacy of prostate cancer detection using power doppler imaging in American and Japanese men

PURPOSE: The aim of this study was to compare the detection rates of tumor vascular flow as measured by power Doppler imaging (PDI) in 2 populations and to determine whether PDI can reduce the number of unnecessary prostate biopsies in men with serum prostate-specific antigen (PSA) concentrations less than 10.1 ng/ml. METHODS: The patient populations were Japanese (group 1) and American (group 2) men with either serum PSA concentrations of 4.1-10.0 ng/ml or abnormal findings on digital rectal examination (DRE) plus PSA concentrations less than 4.1 ng/ml. We compared the overall diagnostic accuracy of DRE, gray-scale transrectal sonography (TRUS), and PDI between the 2 groups. RESULTS: In total, 275 men were studied, 154 in group 1 and 121 in group 2. Cancer was identified in 27% of men in group 1 and in 60% of group 2. Men with cancer in both groups differed significantly in age, peripheral zone volume, and mean number of positive biopsy cores. The sensitivity and specificity of PDI in group 2 were significantly inferior to those in group 1. The negative predictive value (NPV) of PDI was significantly higher for group 1 than for group 2. The NPV of PDI in group 1 was equivalent to that for the combination of DRE and TRUS, whereas the NPV for PDI in group 2 was significantly inferior to that of DRE and TRUS.CONCLUSIONS: Tumor vascularity could be detected by PDI more effectively in Japanese men with cancer than in American men with cancer. We hypothesize that this difference was a result of larger cancer volumes and smaller prostates in the Japanese men. PDI did not provide any performance advantage over DRE and TRUS in avoiding unnecessary biopsies.     

Prostate-specific antigen response and systemic T cell activation after in situ gene therapy in prostate cancer patients failing radiotherapy.

In an extended phase I/II study we evaluated 36 prostate cancer patients with local recurrence after radiotherapy who received single or repeated cycles of replication-deficient adenoviral vector (ADV)-mediated herpes simplex virus-thymidine kinase (HSV-tk) plus ganciclovir (GCV) in situ gene therapy with respect to serum PSA levels, alterations in immune cells, and numbers of apoptotic cells in needle biopsies. An initial cycle of HSV-tk plus GCV gene therapy caused a significant prolongation of the mean serum PSA-doubling time (PSADT) from 15.9 to 42.5 months (p = 0.0271) and in 28 of the injected patients (77.8%) there was a mean PSA reduction (PSAR) of 28%. It took a mean of 8.5 months for the PSA to return to the initial PSA (TR-PSA) value. A repeated cycle of gene therapy failed to significantly extend PSADT but did result in significant increases in PSAR (29.4%) and TR-PSA (10.5 months). Moderately increased serum adenovirus antibody titers were generally observed 2 weeks after initial vector injection. Also at this time there was a statistically significant increase in the mean percent of CD8(+) T cells positive for the HLA-DR marker of activation in peripheral blood (p = 0.0088). Studies using prostate biopsies obtained at the same time point demonstrated that vector DNA was detectable by PCR in most samples yet all patients remained positive for prostate cancer in at least one biopsy core. Further analysis demonstrated a correlation between the level of CD8(+) cells and the number of apoptotic cells in biopsies containing cancer cells (p = 0.042). We conclude that repeated cycles of in situ HSV-tk plus GCV gene therapy can be administered to prostate cancer patients who failed radiotherapy and have a localized recurrence. Biological responses to this experimental therapy including increases in PSADT, PSAR, and TR-PSA, and activated CD8(+) T cells present in the peripheral blood, were demonstrated. Interestingly, the density of CD8(+) cells in posttreatment biopsies correlated with the number of apoptotic cells.     

Prostate-specific antigen screening: friend or foe?

Prostate cancer is the most frequently diagnosed cancer among men in the United States. The prostate-specific antigen (PSA) blood test is the most commonly utilized test to detect early prostate malignancy. Elevated PSA levels suggest to providers the possibility that their patients are at a higher statistical risk of harboring asymptomatic, organ-confined prostate cancer. Although PSA testing has become a primary screening method for prostate cancer in the United States, this test has come under scrutiny. PSA screening lacks a high level of specificity due to frequent false-positive results. Additionally, major health organizations differ in their screening recommendations for use of the PSA test. However, the medical community, and more importantly, patients, must understand the benefits and possible detriments of this screening test. Providers should approach each man individually when recommending a PSA test, noting that many risk factors must be considered in a screening protocol for prostate cancer.     

Preoperative serum prostate-specific antigen (PSA) below 10 microg/l predicts neither the presence of prostate cancer nor the rate of postoperative PSA failure

Recent information on the relationship of serum prostate-specific antigen (PSA) to prostate cancer and new reports on death rates in men warrant a reassessment of how we diagnose and treat prostate cancer. We now know for the first time that the annual death rate from prostate cancer in men > or =65 years of age is only 226 per 100 000 men. At least 40 000 of 100 000 men over age 65 (40%) have invasive prostate cancer as judged by examination of prostates in 3- to 4-mm step-sections. Thus, only 1 of every 177 men 65 years of age or older (226 in 40 000) with invasive prostate cancer dies annually from his cancer. Serum PSA between 2 and 10 microg/L is used almost universally as an indication to biopsy the prostate. When 10-20 biopsies are commonly taken, it is not surprising that approximately 40% of men are biopsy-positive for prostate cancer. Despite this reliance on serum PSA as an indication for biopsy, data at Stanford show no clinically useful relationship between preoperative serum PSA (in the range 2-10 mg/L) and the volume of Gleason grade 4/5 cancer or the volume of Gleason grades 3, 2, and 1 cancer, nor can we show any useful relationship of such preoperative PSA concentrations (2-10 microg/L) to biochemical PSA failure rates after radical prostatectomy. We urgently need a better serum marker for prostate cancer. Because PSA biochemical failure rates after radical prostatectomy are directly proportional to the amount of Gleason grade 4/5 cancer in the prostate, a serum marker of Gleason grade 4/5 carcinoma could be ideal.     

前列腺体积和年龄因素对前列腺特异性抗原等指标在前列腺癌筛选中的影响

目的：探讨前列腺特异抗原（prostate specific antigen,PSA）、前列腺特异性抗原密度（prostate specific antigen density,PSAD）及移行带前列腺特异性抗原密度（prosrate specific antigen density of transition zone,PSAD-TZ）用于前列腺癌筛选时前列腺体积和患者年龄因素对其的影响。方法：回顾性分析因PSA升高和（或）直肠指检异常疑诊前列腺癌而进行直肠前列腺穿刺活组织检查（活检）的295例男性患者的临床资料,根据活检结果分为BPH组（193例）和前列腺癌组（102例）,比较2组中不同前列腺体积以及不同年龄段的PSA、PSAD及PSAD-TZ水平。结果：当前列腺体积小于或等于50mL时,BPH组的PSA、PSAD及PSAD-TZ值与前列腺癌组比较差异均有统计学意义（P〈0．01）;当前列腺体积大于50mL时,2组的PSA值比较差异无统计学意义（P〉0．05）,但PSAD及PSAD-TZ值比较差异有统计学意义（均为P〈0．01）。2组的PSA值随着年龄的增加而升高（均为P〈0．01）。在50-59岁者和60-69岁者中,2组的PSAD及PSAD-TZ值比较差异均有统计学意义（P〈0．05～0．01）;在70～79岁者中,2组的PSAD及PSA-TZ值比较差异无统计学意义。结论：当前列腺体积小于或等于50mL时,检测PSA、PSAD及PSAD-TZ值对前列腺癌的筛选有重要意义,而前列腺体积大于50mL时,需结合PSAD、PSAD-TZ值以及患者的年龄作综合分析。     

Benefits of pre‐biopsy multi‐parametric magnetic resonance imaging scanning in the initial assessment of prostate cancer

Traditionally, men referred for investigation of raised prostate specific antigen (PSA) could expect to be investigated via blind TRUS biopsy. In recent years, the availability of pre‐biopsy imaging with multi‐parametric magnetic resonance imaging (mp‐MRI) has allowed urology centres to improve their triage and care of this patient cohort. The ability to identify discrete lesions for more accurately targeted TRUS, stream patients with anterior lesions for trans‐perineal biopsy, and of course to prevent those with no evidence of clinically significant prostate cancer from being subjected to unnecessary procedures has proved pre‐biopsy mp‐MRI a valuable tool in the assessment and diagnosis of prostate cancer. Our service recently audited the impact of the introduction of mp‐MRI on our prostate cancer assessment pathway. An analysis of the outcomes of 1558 referrals over a 2‐year period, and found that pre‐biopsy imaging has resulted in a marked reduction in unnecessary procedures and more accurate targeting of lesions, leading to improved outcomes for patients.