Sinha Akhouri A, Quast Barry J, Wilson Michael J, Fernandes Eduardo T, Reddy Pratap K, Ewing Stephen L, Gleason Donald F
Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota, USA.
Cancer. 2002 Jun 15;94(12):3141-9. doi: 10.1002/cncr.10604.
Pathologic grade and/or histologic score, extraprostatic extension indicated by invasion of the prostatic capsule, margin, and/or seminal vesicles by prostate cancer cells, serum total prostate-specific antigen (PSA), free PSA, complexed PSA levels and/or their ratios, regional pelvic lymph node metastases, and clinical staging have been used to diagnose and monitor the treatment of prostate carcinoma (PC) patients. The Gleason grading system is also used to grade/score a patient's stage of disease, with lower to higher scores indicating progression of PC. However, Gleason's system cannot be used to distinguish biologically aggressive PCs within a single Gleason score. Our objective was to identify subpopulations (or clones) of aggressive prostate cancers within an individual Gleason score by utilizing biological molecule(s) that also facilitate cancer cell invasion to prostatic stroma and metastasis to the lymph nodes.
Specimens were collected from 97 patients with PC and from 8 patients with benign prostatic hyperplasia. These patients had not been treated with hormonal and/or chemotherapeutic agents before undergoing a prostatectomy at the Minneapolis Veterans Affairs Medical Center. Formalin-fixed, paraffin or paraplast-embedded prostate tissue sections were stained with hematoxylin and eosin for pathologic diagnosis and adjacent sections were stained for for immunohistochemical study. We also collected data on age, race, extraprostatic extension, margin status, seminal vesicle, and lymph node invasion by cancer cells, clinical stage at prostatectomy, and mortality/survival data, including the available presurgery and postsurgery serum total PSA and prostatic acid phosphatase concentrations in patients. Immunohistochemical localization of mouse or rabbit anti-cathepsin B (CB) antibody IgG and mouse antihuman stefin (cystatin) A IgG was quantified using a computer-based image analysis system equipped with Metamorph software.
CB and stefin A identified aggressive and less aggressive clones of PCs within an individual Gleason score. Tumors with a Gleason Score of 6 that are similar histologically and morphologically were heterogeneous with respect to the ratios of CB to stefin A (CB > stefin A, CB = stefin A, and CB < stefin A). We also found a significant positive association (P = 0.0066) between ratios of CB and stefin A (CB > stefin A) and the incidence of pelvic lymph node metastases, but not with ratios of CB less than stefin A and/or ratios of CB equal to stefin A. Patients with Gleason 7 PCs had a higher incidence of positive lymph nodes than those with Gleason Score 6 tumors. Our data indicated that mortality rates increased in patients when the ratios of CB were greater than stefin A.
PC within an individual Gleason score is a heterogeneous tumor that contains clones or subpopulations of aggressive and less aggressive tumors that can be defined by the ratios of CB to stefin A. PC with an aggressive clone can be identified when the ratio of CB is greater than that of stefin A. Less aggressive clones are identified when the ratio of CB is less than that of stefin A or when the ratio of CB is equal to that of stefin A. The ratios of CB to stefin A can be used in the differential diagnosis and treatment of patients with PC. This is the first report to identify phenotypes of aggressive and less aggressive PCs within a Gleason score.
病理分级和/或组织学评分、前列腺癌细胞侵犯前列腺包膜、切缘和/或精囊所提示的前列腺外侵犯、血清总前列腺特异性抗原（PSA）、游离PSA、复合PSA水平和/或其比值、盆腔区域淋巴结转移以及临床分期已被用于诊断和监测前列腺癌（PC）患者的治疗。Gleason分级系统也用于对患者的疾病分期进行分级/评分，分数越低至越高表明PC的进展。然而，Gleason系统不能用于区分单个Gleason评分内具有生物学侵袭性的PC。我们的目标是通过利用也促进癌细胞侵袭前列腺基质和转移至淋巴结的生物分子，在单个Gleason评分内识别侵袭性前列腺癌的亚群（或克隆）。
从97例PC患者和8例良性前列腺增生患者中收集标本。这些患者在明尼阿波利斯退伍军人事务医疗中心接受前列腺切除术之前未接受过激素和/或化疗药物治疗。用苏木精和伊红对福尔马林固定、石蜡或副石蜡包埋的前列腺组织切片进行染色以进行病理诊断，相邻切片进行免疫组织化学研究染色。我们还收集了患者的年龄、种族、前列腺外侵犯、切缘状态、癌细胞对精囊和淋巴结的侵犯、前列腺切除时的临床分期以及死亡率/生存率数据，包括患者术前和术后可用的血清总PSA和前列腺酸性磷酸酶浓度。使用配备MetaMorph软件的基于计算机的图像分析系统对小鼠或兔抗组织蛋白酶B（CB）抗体IgG和小鼠抗人丝抑蛋白（胱抑素）A IgG进行免疫组织化学定位定量。
CB和丝抑蛋白A在单个Gleason评分内识别出侵袭性和侵袭性较弱的PC克隆。组织学和形态学相似的Gleason评分为6的肿瘤在CB与丝抑蛋白A的比值方面是异质性的（CB>丝抑蛋白A、CB =丝抑蛋白A和CB<丝抑蛋白A）。我们还发现CB与丝抑蛋白A的比值（CB>丝抑蛋白A）与盆腔淋巴结转移发生率之间存在显著正相关（P = 0.0066），但与CB小于丝抑蛋白A的比值和/或CB等于丝抑蛋白A的比值无关。Gleason评分为7的PC患者的阳性淋巴结发生率高于Gleason评分为6的肿瘤患者。我们的数据表明，当CB的比值大于丝抑蛋白A时患者的死亡率增加。
单个Gleason评分内的PC是一种异质性肿瘤，包含侵袭性和侵袭性较弱的肿瘤克隆或亚群，可通过CB与丝抑蛋白A的比值来定义。当CB的比值大于丝抑蛋白A时可识别出具有侵袭性克隆的PC。当CB的比值小于丝抑蛋白A或CB的比值等于丝抑蛋白A时可识别出侵袭性较弱的克隆。CB与丝抑蛋白A的比值可用于PC患者的鉴别诊断和治疗。这是第一份在Gleason评分内识别侵袭性和侵袭性较弱的PC表型的报告。
