血清PSA及超声引导穿刺活检对前列腺癌病理分期预测价值研究

目的 研究血清前列腺特异性抗原(PSA)及超声引导穿刺活检对前列腺癌病理分期的预测价值.方法 选取200例经直肠超声引导前列腺穿刺活检确诊为前列腺癌的患者的临床资料进行研究.分析患者的血清PSA、穿刺活检阳性百分数及Gleason评分3个参数与前列腺癌病理分期的相关性;同时对比性分析以上3个参数在不同病理分期前列腺癌患者中的差异情况.结果 血清PSA、穿刺活检阳性百分数及Gleason评分均与前列腺癌患者的病理分期呈正相关(P﹤0.001);D期前列腺癌患者的血清PSA水平明显高于A期、B期、C期前列腺癌患者(P﹤0.05),而A期、B期、C期前列腺癌患者的血清PSA水平两两之间比较,差异均无统计学意义(P﹥0.05);C期与D期前列腺癌患者的穿刺活检阳性百分数比较,差异无统计学意义(P﹥0.05),而其他各分期间穿刺活检阳性百分数两两比较,差异均有统计学意义(P﹤0.05);A期与C期、B期与C期、A期与D期、B期与D期前列腺癌患者的Gleason评分比较,差异均有统计学意义(P﹤0.05),而A期与B期、C期与D期前列腺癌患者的Gleason评分比较,差异无统计学意义(P﹥0.05).结论 血清PSA、穿刺活检阳性百分数及Gleason评分均可单独用于前列腺期病理分期的预测,同时该3个参数在区分前列腺癌病理分期方面也发挥一定辅助作用.     

PSA正常的前列腺癌患者临床特点分析北大核心

目的:根据PSA低于4 ng/mL的前列腺患者的临床资料及随访情况,探讨此类前列腺癌患者的临床特点,对PSA正常的前列腺癌患者的诊断及治疗提供临床思路。方法:收集2013年01月至2018年01月西京医院及西安交通大学第二附属医院收治的35例PSA正常的前列腺癌患者的临床资料。观察此类患者的发病情况、临床就诊特征、病理学特征、危险程度分级、Gleason评分、治疗及预后。总结PSA正常的前列腺癌患者的临床诊断及治疗特征。结果:PSA正常的前列腺癌患者占同期确诊前列腺癌的5.72%。35例患者中,28例主要因为排尿困难为症状就诊,血清PSA 0.91~3.96 ng/mL,平均(2.73±0.77)ng/mL。f/tPSA>0.16为5例,占14.3%,前列腺体积平均值为(68.4±36.66)cm^(3),12例患者行磁共振检查,10例报告提示前列腺癌可能,2例报告为前列腺增生,未发现前列腺癌影像学证据。13例患者行B超引导下经直肠前列腺穿刺活检术,11例患者病理诊断为前列腺癌,2例患者未发现肿瘤证据。行经尿道前列腺电切术共24例,其中包括2例穿刺活检未发现肿瘤证据患者,并于术后12周行前列腺癌根治性手术。病理结果显示:29例为前列腺腺癌,2例为肉瘤,2例为小细胞癌,1例为鳞癌,1例为黏液腺癌。切缘阳性10例(28.6%),侵犯精囊9例(25.71%),淋巴结阳性13例(37.14%)。TNM分期:T期6例,T期10例,T期7例,T期12例。危险度分级:低危患者5例(14.28%),中危9例(25.71%),高危21例(60%)。Gleason评分7分以下为6例(20.69%),7分为9例(31.03%),7分以上为14例(48.28%)。随访时间13~72月,术后密切监测PSA水平,术后生化复发共13例(37.14%),21例患者死亡,16例为前列腺特异性死亡。术后1、2、3年的生存率分别为:97.14%,88.57%,77.14%。结论:PSA正常的前列腺癌因无明显的临床就诊特征,精囊侵犯检出率高、Gleason评分及危险程度均偏高,3年生存率仅为77.14%。对于此类患者,不应以惯性思维认为PSA水平低,临床风险小,应更积极的完善检查,调整治疗策略,给此类患者带来更多的生存获益。     

磁共振成像(MRI)对前列腺癌分期的临床意义

目的 探讨临床分期和磁共振成像(MRI)分期预测前列腺癌病理分期的临床意义。方法 对32例病理证实的局限性前列腺癌行根治性手术前经直肠指诊进行临床分期及MRI分期预测术后前列腺病理分期结果,评价其预测前列腺癌病理分期的诊断性结果。结果 本组32例前列腺癌中,临床分期局限于前列腺内的肿瘤(B期)30例,10例前列腺癌根治术后病理诊断有前列腺包膜及包膜外浸润,1例左髂血管旁淋巴结转移癌,36.7％(11/30)病例临床分期偏低,2例临床分期为C期病例术后1例为B期,临床分期偏高。而MRI诊断的30例前列腺癌中,分期局限于前列腺内的肿瘤(B期)21例中,4例前列腺根治术后病理诊断为C期,19.1％(4/21)的病例MRI分期偏低;9例MRI分期为C期病例1例术后为B期,分期偏高,另1例术后为D1期,分期偏低。直肠指诊临床分期和MRI分期预测前列腺癌的病理结果有显著相关性(P=0.002)。临床分期和MRI分期对局限于前列腺内肿瘤的预测(PPV)分别为63.3％和80.9％;对浸润包膜及包膜外肿瘤的预测(NPV)分别为50.0％和88.9％。MRI对前列腺癌病理分期的预测更具有特异性和较高的准确性,能更好的预测前列腺癌的病理结果(P=0.023)。结论 MRI分期较直肠指诊临床分期能更好地预测局限于前列腺内的肿瘤,对前列腺包膜及包膜以外浸润的肿瘤能进行更准确分     

临床分期和磁共振成像(MRI)对前列腺癌分期的临床意义

目的：探讨临床分期和磁共振成像(MRI)分期预测前列腺癌病理分期的临床意义。方法：对32例局限性前列腺癌术前经直肠指诊进行临床分期及MRI分期预测前列腺癌根治术后的病理分期结果，评价诊断性实验结果。结果：直肠指诊临床分期和MRI分期预测前列腺癌的病理结果有显著相关性(P=0．002)。临床分期和MRI分期对局限于前列腺内肿瘤的预测(PPV)分别为63.3％和80．9％；对浸润包膜及包膜外肿瘤的预测(NPV)分别为50．0％和88．9％。MRI对前列腺癌病理分期的预测更具有特异性和较高的准确性，能更好的预测前列腺癌的病理结果(P=0．023)。结论：MRI较直肠指诊能更好地预测局限于前列腺内的肿瘤，对前列腺包膜及包膜以外浸润的肿瘤能进行更准确的分期。     

前列腺特异性抗原表达与前列腺癌组织学分级的相关性

目的　探讨血清和组织中前列腺特异性抗原 (PSA )的表达水平 ,与前列腺癌 (Pca)组织学分级的相关性。方法　采用免疫组化ABC法 ,对 70例Pca组织进行PSA检测 ,同时采用放免法测定患者血清PSA浓度。结果　PSA在Pca组织中阳性表达率为 79% ,组织PSA与前列腺癌Gleason′s分级呈显著负相关 (γ =-0 .792 ,P <0 .0 1) ,而血清PSA与组织PSA及前列腺癌Gleason′s分级无相关性。结论　组织PSA与前列腺癌组织学分级间的相关性可能协助准确判断前列腺癌分级分期及预后     

不同PSA水平的国人首次前列腺穿刺活检所需穿刺针数的研究

目的 比较不同PSA水平患者采用6点法和12点法的前列腺活检阳性率,探讨针对不同的患者人群设计国人合理的首次前列腺穿刺点数。 方法 通过研究首次接受直肠超声引导经会阴前列腺穿刺的425例患者,在PSA的不同水平段,比较6点法和12点法的阳性率的差异,以及阳性患者穿刺活检Gleason评分与前列腺癌根治术后病理标本Gleason评分之间的差异。 结果 425例患者中6点法穿刺224例,12点法201例。PSA＞20 ng/ml的患者6点法与12点法的阳性率分别为85.3%、77.5%（P＞0.05）;PSA10~20 ng/ml患者6点法和12点法的阳性率分别为33.8%、39.1%（P＞0.05）。两者的12点法比6点法没有更高的阳性率。PSA≤10 ng/ml患者6点法和12点法的阳性率分别为24.1%、45.8%（P＜0.05）,12点法比6点法阳性率显著提高。结论 对于国人首次行前列腺穿刺,若PSA＞20 ng/ml推荐行6点法穿刺;PSA≤10 ng/ml推荐12点法穿刺,而PSA在10~20 ng/ml则两种穿刺方法均可以选用。     

磁共振成像(MRI)对前列腺癌分期的临床意义(英文)

目的探讨临床分期和磁共振成像(MRI)分期预测前列腺癌病理分期的临床意义。方法对32例病理证实的局限性前列腺癌行根治性手术前经直肠指诊进行临床分期及 MRI 分期预测术后前列腺病理分期结果,评价其预测前列腺癌病理分期的诊断性结果。结果本组32例前列腺癌中,临床分期局限于前列腺内的肿瘤(B 期)30例,10例前列腺癌根治术后病理诊断有前列腺包膜及包膜外浸润,1例左髂血管旁淋巴结转移癌,36.7%(11/30)病例临床分期偏低,2例临床分期为 C 期病例术后1例为 B 期,临床分期偏高。而 MRI 诊断的30例前列腺癌中,分期局限于前列腺内的肿瘤(B 期)21例中,4例前列腺根治术后病理诊断为 C 期,19.1%(4/21)的病例 MRI 分期偏低;9例 MRI 分期为 C 期病例1例术后为 B 期,分期偏高,另1例术后为 D1期,分期偏低。直肠指诊临床分期和 MRI 分期预测前列腺癌的病理结果有显著相关性(P=0.002)。临床分期和 MRI 分期对局限于前列腺内肿瘤的预测(PPV)分别为63.3%和80.9%;对浸润包膜及包膜外肿瘤的预测(NPV)分别为50.0%和88.9%、MRI 对前列腺癌病理分期的预测更具有特异性和较高的准确性,能更好的预测前列腺癌的病理结果(P=0.023)。结论 MRI 分期较直肠指诊临床分期能更好地预测局限于前列腺内的肿瘤,对前列腺包膜及包膜以外浸润的肿瘤能进行更准确的分期。     

前列腺癌患者PSA水平与肿瘤分级及临床分期的关系

本研究收集1997年1月至1999年12月前列腺癌(prostatic cancer,PCA)75例,分别检测了血清前列腺特异抗原(prostate specipic antigen,PSA)及前列腺特异抗原密度(prostate antigen density,PSAD),探讨PSA和PSAD与前列腺癌的病理分级及临床分期的关系.     

HER2和Ki-67在前列腺癌中的表达及其与分级和预后的关系

目的:探讨前列腺癌组织中HER2和Ki-67的表达意义,及其与前列腺癌Gleason分级和预后的关系。方法:应用免疫组织化学的方法,检测原癌基因HER2和基因增殖细胞核抗原Ki-67在102例前列腺癌中的表达情况。结果:在前列腺癌中,分化越差,HER2和Ki-67的表达强度和阳性率越高,预后越差,差异有统计学意义(P<0.05)。结论:HER2和Ki-67可以作为判断前列腺癌预后较可靠的指标,结合Gleason评分和分级,能为临床诊断和预测预后提供依据。     

前列腺特异性抗原的检测对前列腺癌及前列腺增生的诊断意义

目的　探讨血清总前列腺特异性抗原 (t PSA)、游离PSA (f PSA)、PSA密度 (PSAD )及其f PSA/t PSA比值对前列腺癌 (PCa)及前列腺增生 (BPH )的诊断价值。方法　采用酶联免疫分析方法 (ELISA )检测未经治疗的 62例BPH患者和 2 4例PCa患者血清f PSA、t PSA水平 ,并计算f PSA/t PSA值和PSAD ,对检测结果进行统计学处理。结果　BPH组与PCa组的f PSA、t PSA水平均明显高于对照组 (P <0 .0 1) ;前列腺癌组的f PSA /t PSA值明显小于对照组及前列腺癌增生组 (P <0 .0 1) ;PCa组PSAD明显大于对照组和BPH组 (P <0 .0 1)。结论　检测f PSA/t PSA和PSAD比单一检测f PSA、t PSA可显著提高对PCa诊断的特异性及符合率 ,对前列腺体积较大的BPH和PCa患者 ,检测PSAD更有意义     

Influence of Adipocytokines and Periprostatic Adiposity Measurement Parameters on Prostate Cancer Aggressiveness

Background: The relationship between obesity and prostate cancer aggressiveness is controversial in recentstudies, partly because BMI is the only generally applied marker of obesity. Our study aimed at evaluatingthe correlation of periprostatic fat (PF) on magnatic resonance imaging (MRI) and adipocytokines withprostate cancer aggressiveness. Patients and method: A total of 184 patients who underwent radical retropubicprostatectomy (RRP) were analyzed retrospectively; different fat measurements on MRI slices and levels ofadipocytokines were compared with the clinical and pathologic factors using SSPS ver.13.0. Result: The PF ratesshowed a statistically significant variation (p=0.019, 0.025) among groups, that is to say, more adipose tissue wasdistributed in periprostatic areas of high risk patients. Logistic regression analysis adjusted for age revealed astatistically association between the PF, the ratio and the risk of having high-risk disease (p=0.031, 0.024). Thelevels of IL-6, leptin and c-reactive protein (CRP) significantly increased with the aggressiveness of prostate cancer,and also with PF and its ratio. The strongest correlation was seen between IL-6 and PF (Pearson r coefficient=0.67,P<0.001). No association was observed between adipocytokines and BMI. Conclusion: Periprostatic adipositynot only affects prostate cancer aggressiveness, but also influences the secretion of adipocytokines. IL-6, PF andCRP have promoting effects on progression of prostate cancer.     

肿瘤微环境与前列腺癌骨转移研究进展

前列腺癌（prostate cancer, PCa）转移中大约80%是发生骨转移,是造成患者死亡的主要原因。前列腺癌骨转移主要呈现成骨和破骨混合性损伤。然而,诱发肿瘤细胞转移到骨以及引起混合样病变的机制仍不十分清楚。宿主微环境与前列腺癌细胞间的相互作用是其中一个重要原因。本文主要讨论宿主微环境如何影响前列腺癌骨转移各个阶段的发生及其中的机制,探讨多种细胞因子、分泌蛋白、微环境中的免疫细胞、成骨细胞、破骨细胞等分泌的因子在前列腺癌骨转移中的重要作用。     

低氧对前列腺癌PC3细胞上皮间质转化的影响

 目的 探讨低氧对前列腺癌细胞上皮间质转化的影响。方法 分别在常氧（常氧组）和低氧（低氧组）条件下培养PC3细胞24 h,细胞增殖MTT实验检测低氧对前列腺癌PC3细胞增殖力的影响,Transwell侵袭实验评估低氧对前列腺癌PC3细胞侵袭力的影响,Western blot检测HIF-1α、E-cadherin、N-cadherin和Vimentin的表达水平。另外,在常氧条件下用siRNA抑制HIF-1α表达（干扰组）,用Western blot检测E-cadherin、N-cadherin和Vimentin的表达水平变化。结果 与常氧组比较,低氧组前列腺癌PC3细胞的增殖力和侵袭力增加,HIF-1α表达水平增加（P=0.0004）,HIF-1α向核内转位;N-cadherin（P<0.0001）和Vimentin（P<0.0001）的表达水平显著增加,E-cadherin的表达水平显著下降（P<0.0001）。同时,干扰组跟常氧组比较,抑制HIF-1α表达使N-cadherin（P=0.0002）和Vimentin（P=0.0002）的表达水平显著下降,而使E-cadherin的表达水平显著增加（P<0.0001）。结论 低氧可能通过调节HIF-1α表达促进前列腺癌PC3细胞的上皮间质转化。     

前列腺腺癌组织中HPV16/18蛋白的表达及意义

 目的 探讨高危型人乳头瘤病毒16/18（HPV16/18）在人体前列腺腺癌组织中的表达及其与临床病理参数的关系。方法 选取86例前列腺腺癌和80例前列腺增生组织标本,通过免疫组织化学Max Vision二步法检测HPV16/18蛋白表达情况。结果 前列腺腺癌组和前列腺增生组的HPV16/18阳性表达率分别为22.58%和11.25%,差异有统计学意义（P=0.018）。在前列腺腺癌组内,HPV16/18的表达与Gleason评分和临床分期有一定的关系,差异有统计学意义（均P<0.05）,而与患者PSA水平、有无脉管侵犯、有无淋巴结转移和有无远处转移关系不大,差异无统计学意义（均P>0.05）。结论 HPV16/18与前列腺腺癌的发生发展有一定的关系,有可能成为前列腺腺癌早诊早治的生物学指标之一。     

叶黄素对人前列腺癌PC3细胞增殖和凋亡影响的机制

目的 探究叶黄素对人前列腺癌PC3细胞增殖和凋亡影响的作用机制,为前列腺癌预防及治疗提供新的理论依据。方法 不同浓度叶黄素作用于PC3细胞,CCK8法检测细胞增殖情况;流式细胞仪检测细胞周期分布和凋亡变化;细胞划痕和Transwell实验观察细胞迁移和侵袭能力;RT-PCR和Western blot技术检测细胞中Bax、Bcl-2的mRNA水平和蛋白表达。结果 叶黄素显著抑制PC3细胞的增殖,并呈时间和浓度依赖性。叶黄素可以将细胞生长阻滞在G0/G1期,抑制细胞迁移和侵袭;还可促进细胞凋亡,使Bcl-2表达下降,Bax表达上升。叶黄素可在转录水平上下调Bcl-2 mRNA和上调BaxmRNA。结论 叶黄素抑制PC3细胞增殖并促进其凋亡,其机制可能与阻滞细胞周期、抑制细胞迁移、侵袭以及调节凋亡相关基因和蛋白表达有关。     

长链非编码RNA-MALAT1对前列腺癌细胞增殖及凋亡的影响

 目的 探讨长链非编码RNA-MALAT1对激素依赖性前列腺癌细胞增殖与凋亡的影响及其作用机制。方法 以激素依赖性前列腺癌细胞PC3和LNCaP为研究对象，对细胞进行MALAT1过表达及干扰处理，并通过MTT、流式细胞仪、基质胶和平板克隆等方法检测MALAT1过表达或干扰对细胞生物学行为的影响。Western blot检测MALAT1对与细胞周期及凋亡相关蛋白Cyclin D1、Bcl-2、Bax及p-ERK1/2表达的影响。结果 与对照组比较，MALAT1组细胞的增殖能力明显增强（P<0.01），克隆形成能力、血管生成能力增强，G₀/G₁期细胞数量增多，凋亡率降低；si-MALAT1组细胞增殖能力明显低于对照组（P<0.01），克隆形成能力、血管生成能力减弱，G₀/G₁期细胞数量减少，凋亡率升高。结论 MALAT1对前列腺癌的发生发展有促进作用，抑制MALAT1表达可能对前列腺癌的治疗具有重要意义。     

不同表观扩散系数对前列腺癌盆腔转移性淋巴结的定性诊断价值

 目的 探讨不同表观扩散系数（ADC）对前列腺癌盆腔转移性淋巴结的定性诊断价值。方法 收集58例前列腺癌伴盆腔淋巴结肿大患者的临床及磁共振资料；盆腔肿大淋巴结ADC值的获取分别采用局部测量法（partial measurement）与整体测量法（overall measurement）；采用Bland-Altman法进行一致性分析，并以受试者工作曲线（ROC）比较两种ADC值的诊断效能。结果 58例前列腺癌患者共计69枚肿大淋巴结进行入组研究，经病理证实后，其中炎性淋巴结22枚、转移性淋巴结47枚。Bland-Altman结果显示：局部测量法（ADC_partial）与整体测量法（ADC_overall）获取的ADC值存在8.7%（6/69）在95%一致性界限（95% limits of agreement, 95%LoA）之外，说明其一致性较差，提示ADC_partial与ADC_overall是淋巴结ADC值的两种不同测量方法，不能相互替代。ROC曲线结果显示：ADCpartial对前列腺癌盆腔转移性淋巴结的敏感度、特异性以及曲线下面积分别为82.98%、90.91%以及0.927；ADC_overall对前列腺癌盆腔转移性淋巴结的敏感度、特异性以及曲线下面积分别为89.36%、95.45%以及0.962；ADC_overall的诊断效能优于ADC_partial（Z=2.013, P=0.044）。结论 ADC_partial与ADC_overall均对前列腺癌盆腔转移性淋巴结的定性诊断有着较大的优势，ADC_overall的诊断效能更高。     

Evaluation of Gleason Grade Group 5 in a Contemporary Prostate Cancer Grading System and Literature Review

IntroductionThe aim of this study was to validate contemporary grading systems, in particular, the Gleason grade group (GGG) 5.Patients and MethodsWe retrospectively reviewed the clinicopathologic data of 176 patients who underwent radical prostatectomy and whose pathologic results were GGG 4 or 5. The endpoints were biochemical recurrence (BCR) and castration-resistant prostate cancer (CRPC).ResultsThe GGG 4 group was composed of 69 patients. The GGG 5 group consisted of 78 patients with GS 4+5 and 29 patients with GS 5+4 or higher. The 5-year BCR-free survival rates for men with GGG 4, GS 4+5, and GS 5+4 or higher were 59%, 54%, and 20%, respectively, and the 5-year CRPC-free survival rates were 98%, 100%, and 88%, respectively. Both the BCR- and CRPC-free survival rates were significantly higher in GS 4+5 than in GS 5+4 or higher (P < .001 and P = .002, respectively), but there were no significant differences between GGG 4 and GS 4+5 (P = .702 and P = .803, respectively). The multivariate analysis demonstrated that GS 5+4 or higher (hazard ratio, 3.4; P = .002) and lymphovascular invasion (hazard ratio, 3.4; P < .001) greatly affected BCR.ConclusionOur follow-up study revealed that men with GS 4+5 and those with GGG 4 had a similar prognosis. However, there was a significant discrepancy in prognosis between GS 4+5 and GS 5+4 or higher. This suggested that GGG 4 and 5 in the contemporary prostate cancer grading system should be reviewed. Furthermore, lymphovascular invasion may be useful to subgroup these pathologically high-risk patients.     

Survival of Patients with Prostate Cancer in Yazd,Iran

Background: Prostate cancer is the second leading cause of cancer death in men worldwide. Several factorssuch as availability of screening tests, and dietary, other lifestyle, environmental and genetic influences contributeto worldwide disparities in prostate cancer incidence and mortality rates. Our aims were to investigate patientcharacteristics at the time of diagnosis, common treatment strategies employed and survival in an Iranian malepopulation with prostate cancer. Materials and Methods: Archives of Pathology Departments of five referralcenters affiliated with the School of Medicine of Shahid Sadoughi University in Yazd province were reviewed.Paraffin-embedded blocks were reviewed by two independent pathologists to confirm the diagnosis. Thelatest modification of the Gleason Scoring System was adopted to determine pathological grading. Followingpathological evaluation, patients were contacted via telephone to acquire information regarding their currentstatus. Results: Pathology blocks were available for 113 patients. However, upon phone contacts, we were unableto determine the survival status in 23 patients (response rate=83%). Therefore, 90 patients were enrolled in thefinal analysis. The median follow-up time was 6.0 years (ranging from 0.3 to 8.8 years). There were 30 deathattributed to prostate cancer in the study group. Kaplan-Meier analysis revealed that patient age at the timeof diagnosis was a significant predictor of survival. Another significant predictor of poorer survival was highertumor grade. Conclusions: Our observations indicate that age and pathological grade can negatively affectsurvival of individuals with prostate cancer in Iran.     

Retrospective Study of Predictors of Bone Metastasis in Prostate Cancer Cases

Introduction: The purpose of this study was to identify clinical profiles of patients with low risk of having bonemetastases, for which bone scanning could be safely eliminated. Materials and Methods: This retrospective crosssectional study looked at prostate cancer patients seen in the Urology Departments in 2 tertiary centres over the11 year period starting from January 2000 to May 2011. Patient demographic data, levels of PSA at diagnosis,Gleason score for the biopsy core, T-staging as well as the lymph node status were recorded and analysed.Results: 258 men were included. The mean age of those 90 men (34.9%) with bone metastasis was 69.2±7.3 years.. Logistic regression found that PSA level (P=0.000) at diagnosis and patient’s nodal-stage (P=0.02) were theonly two independent variables able to predict the probability of bone metastasis among the newly diagnosedprostate cancer patients. Among thowse with a low PSA level less than 20ng/ml, and less than 10ng/ml, bonemetastasis were detected in 10.3% (12 out of 117) and 9.7% (7 out of 72), respectively. However, by combiningPSA level of 10ng/ml or lower, and nodal negative as the two criteria to predict negative bone scan, a relativelyhigh negative predictive value of 93.8% was obtained. The probability of bone metastasis in prostate cancercan be calculated with this formula: -1.069+0.007(PSA value, ng/ml)+1.021(Nodal status, 0 or 1)=x Probabilityof bone metastasis=2.718x/1+2.718x. Conclusion: Newly diagnosed prostate cancer patients with a PSA level of10ng/ml or lower and negative nodes have a very low risk of bone metastasis (negative predictive value 93.8%)and therefore bone scans may not be necessary.