Prostate Carcinoma Progression Research Articles

A Neuroendocrine/Small Cell Prostate Carcinoma Xenograft—LuCaP 49

The late stages of progression of prostate carcinoma are typically characterized by an androgen-insensitive, rapidly proliferative state. Some late-stage tumors are composed predominantly of neuroendocrine cells. Virtually no animal models of a neuroendocrine/small cell variant of prostate carcinoma are available for experimental studies. We report a human neuroendocrine/small cell prostate carcinoma xenograft that was developed from a nodal metastasis of a human prostate carcinoma and that has been propagated as serial subcutaneous implants in severe combined immunodeficient mice for >4 years. Designated LuCaP 49, all tumor passages exhibit a neuroendocrine/small cell carcinoma phenotype-insensitivity to androgen deprivation, expression of neuroendocrine proteins, lack of expression of prostate-specific antigen or androgen receptor, and an unusually rapid growth (a doubling time of 6.5 days) for prostate cancer xenografts. Genetically this tumor exhibits loss of heterozygosity for the short arm of chromosome 8 and has a complex karyotype. This xenograft should prove to be useful in the investigation of mechanisms underlying the androgen-insensitive state of progressive prostate carcinoma.

Prediction of pelvic lymph node metastasis by the ratio of cathepsin B to stefin A in patients with prostate carcinoma.

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.

Positive Surgical Margins After Radical Retropubic Prostatectomy: The Influence of Site and Number on Progression

We assessed the effect of location and number of positive margins on biochemical progression in patients after radical retropubic prostatectomy for prostate cancer. The incidence, location and number of positive surgical margins as well as recurrence and time to recurrence were evaluated in a consecutive series of 734 men who underwent radical retropubic prostatectomy for localized prostate cancer from 1992 through February 1999. Surgical margins were positive in 210 patients (29%), of whom 157 (75%) and 53 (25%) had 1 and more than 1 positive margin, respectively. Of the patients 53 (25%) with tumor at any inked margin had biochemical recurrence. We identified no significant association of a particular location with biochemical recurrence. Bladder neck location did not carry an increased risk of recurrence (hazard ratio 1.23, 95% confidence interval 0.54 to 2.80). However, these findings were made in a limited number of cases with positive bladder neck margins. Patients with more than 1 positive surgical margin were at increased risk for recurrence compared with those with a single positive surgical margin (hazard ratio 2.19, 95% confidence interval 1.11 to 4.32). In addition, prostate specific antigen greater than 20 ng./ml. and seminal vesicle invasion were significant predictors of progression. In patients with localized prostate cancer and positive surgical margins biochemical progression is not dictated by the specific location of a positive margin. However, multiple positive margins are associated with a significantly increased risk of biochemical recurrence. Longer followup and larger sample size are necessary to confirm these findings.

Chromosomal changes in locally recurrent, hormone-refractory prostate carcinomas by karyotyping and comparative genomic hybridization

The genetic mechanisms of prostate cancer recurrence during hormonal therapy are largely unknown. So far, data from conventional karyotype analysis on hormone-refractory prostate carcinomas have not been published, mainly because of the difficulties in obtaining fresh hormone-refractory prostate carcinoma samples and getting metaphases from them. Here, we have studied chromosomal changes in 12 locally recurrent, hormone-refractory prostate carcinomas using karyotyping and CGH that revealed genetic aberrations in all tumors. Loss of the Y chromosome was the most common (89%) finding, and tetraploidy or near-tetraploidy was detected in all tumors. Also non-random translocations were found in 56% of the tumors. The present study indicates that clonal chromosomal aberrations in hormone-refractory prostate carcinomas are more common than in untreated primary tumors, and also, further studies on the frequency and significance of translocations in prostate carcinoma progression during hormonal therapy are warranted.

DEDIFFERENTIATION OF PROSTATE CANCER GRADE WITH TIME IN MEN FOLLOWED EXPECTANTLY FOR STAGE T1C DISEASE

We assess whether the Gleason grade changes in men followed expectantly with clinical stage T1c prostate cancer. We studied 70 men with stage T1c prostate cancer who underwent watchful waiting with repeat needle biopsy sampling to assess for progression. After the initial cancer diagnosis all men had at least 1 other biopsy demonstrating cancer. Of 70 cases 9 (12.9%) showed a significant change in grade from Gleason scores 6 or less to 7 or greater. The average followup of those patients without a change in grade was 22 months and greater than those with a change in grade. There was no difference between the groups with and without changes in grade in regard to initial prostate specific antigen (PSA), percent-free PSA, or PSA density or velocity. Of 9 cases there were 5 (56%) and 8 (89%) with grade change that occurred at 12 and 15 months or less after initial biopsy, respectively. In contrast, only 1 of 24 (4%) patients in whom last re-biopsy was performed 24 months or greater after the initial cancer diagnosis had a change in grade. Of the 21 men who underwent radical prostatectomy 5 (24%) had worsening of grade on the radical prostatectomy specimen compared to biopsy, with a mean interval of 18 months between the initial cancer diagnosis and prostatectomy. This prevalence of grade change is less than in our population that underwent prostatectomy within 1 to 3 months after biopsy. Because most grade changes occurred relatively soon after biopsy, it implies that tumor grade did not evolve but rather the higher grade component was not initially sampled. During a 1 1/2 to 2-year period after biopsy there is no evidence that prostate cancer grade worsens significantly. Men with prostate cancer need not feel concerned about waiting several months before undergoing surgery after biopsy. Furthermore, men undergoing watchful waiting can be reassured that there is little evidence that prostate cancer grade worsens during the short term.

E-cadherin expression in prostate cancer: A broad survey using high-density tissue microarray technology

E-cadherin is a calcium 2+−dependent cell-adhesion molecule that determines epithelial development in the embryo and maintains adult differentiated epithelium and homeostasis. Aberrant or decreased expression has been reported to be associated with prostate carcinoma progression. The degree of E-cadherin expression in prostate cancer remains controversial. Some studies have reported decreased expression of E-cadherin as tumors advance and metastasize. Other studies have not demonstrated this relationship. To address these variations, we undertook a study to systematically evaluate E-cadherin expression in a broad range of prostate tissue. Benign prostate, clinically localized prostate cancer, and hormone-refractory metastatic prostate cancer were analyzed under uniform conditions using high-density tissue microarrays (TMA). Formalin-fixed, paraffin-embedded prostate carcinoma from men with clinically localized prostate carcinoma and autopsy material from men who died of widely metastatic, hormone-refractory prostate carcinoma were arrayed into 6 high-density TMA blocks. Benign and atrophic prostate tissue and high-grade prostatic intraepithelial neoplasia (PIN) were also included from the clinically localized cases. Immunohistochemistry was performed using the immunoglobulin G1 mouse monoclonal antibody (HECD-1; Zymed, San Francisco, CA). Membranous staining was recorded as low (aberrant) or high (normal). E-cadherin expression was considered aberrant if less than 70% of the cells had strong membranous staining. A total of 1,220 prostate TMA samples were analyzed. High (normal) E-cadherin expression was seen in 87% of 757 benign, 80% of 41 high-grade PIN, 82% of 325 prostate carcinoma and 90% of 97 hormone-refractory prostate carcinoma TMA samples. Mean E-cadherin expression was determined for each of the 128 clinically localized prostate cancer cases. Aberrant E-cadherin expression showed a statistical trend toward an association with positive surgical margins (P =.012), higher Gleason score (P =.18), and prostate-specific antigen (PSA) failure (Kaplan-Meier analysis, log-rank P =.09). There was a statistically significant association between aberrant E-cadherin expression and larger tumor size (P =.01). No significant associations were seen with extraprostatic extension and seminal vesicle invasion. The current study shows a broad-spectrum approach to evaluating E-cadherin protein expression in prostate carcinoma. Clinically localized prostate tumors, treated with surgery alone, show a high level of E-cadherin expression. Aberrant expression was identified in tumors with positive surgical margins, higher Gleason score, and a higher rate of PSA failure. However, these trends were not statistically significant. A statically significant association between aberrant E-cadherin expression and larger tumor size was identified. In the metastatic hormone-refractory prostate tumors, E-cadherin expression was vastly expressed, and only rare cases had aberrant expression. Therefore, the findings of this study are most consistent with a transient down-regulation of E-cadherin in localized prostate cancer. Metastatic prostate cancer shows strong E-cadherin expression as determined by anti-E-cadherin antibody HECD-1. HUM PATHOL 32:690-697. Copyright © 2001 by W.B. Saunders Company

Expression of cathepsins B and S in the progression of prostate carcinoma.

Cathepsins B and S (CatB, CatS) are lysosomal cysteine proteases which, among other functions, appear to play a role in cancer progression in different tumor models due to their matrix-degrading properties. To investigate their possible involvement in the development of prostate carcinoma, we immunohistochemically analyzed CatB and CatS in 38 primary human prostatic adenocarcinomas, as well as concomitant high-grade prostatic intra-epithelial neoplasia, nodular hyperplasia and normal tissue. CatB expression was observed in 28 (74%) and CatS in 32 (84%) carcinomas, being concomitant in 24 cases (63%). High-grade intra-epithelial neoplasia expressed CatB in 20/23 cases (87%), and a similar result was obtained for CatS, with expression of both coinciding in 18 cases (78%). In non-neoplastic tissue, strong expression of both proteases was observed in macrophages, inflamed glands and transitional metaplasia, whereas atrophic glands and basal cells of normal glands displayed intense CatB positivity. We conclude that CatB and CatS are often expressed together in neoplastic prostatic cells from pre-invasive to invasive and clinically detectable stages, suggesting a putative role in local invasion, though other functions cannot be ruled out.

Mitoxantrone in patients with prostate specific antigen progression after local therapy for prostate carcinoma

Molecular mechanisms of chemotherapy resistance are present in prostate carcinoma, some of which increase after androgen ablation (AA) therapy. Therefore, the authors hypothesized that chemotherapy in patients with prostate specific antigen (PSA) progression after local therapy, before androgen ablation therapy, will have greater antitumor activity. Twenty-three hormone-naive patients with PSA progression after prostatectomy or radiation therapy were registered in this study. Twenty-two were treated with 10 mg/m(2) of mitoxantrone initially, followed by 12 mg/m(2) every 3 weeks for a maximum of 8 cycles. Prostatectomy specimens were assessed, when possible, for topoisomerase II alpha, multidrug resistance protein MRP, and bcl-2 by immunohistochemistry. Twenty-two patients received a total of 131 cycles of therapy. Three patients had transient Grade 3 or 4 neutropenia without fever. During treatment, 10 of 22 patients showed a decrease in PSA, without an associated decrease in testosterone. In this group of 10 patients, the mean PSA decrease was 29% at 3 months and 43% at 6 months. Overall, 4 of 22 patients had a decrease in PSA of greater than or equal to 50%. The PSA decreased in three of seven patients whose cancer overexpressed MRP and in three of seven patients who overexpressed bcl-2. No patient with overexpression of topoisomerase II alpha (n = 4) had a decrease in PSA during the study. To the authors' knowledge, this is the first reported study of mitoxantrone in patients with hormone-naive prostate carcinoma and PSA progression after local therapy; mitoxantrone was safe and biochemically active, similar to prior studies in hormone refractory prostate carcinoma, suggesting that critical molecular mechanisms of chemotherapy resistance are present independent of AA. Further studies are warranted to determine whether pharmacogenomic assessment of topoisomerase II, MRP, or bcl-2 may predict for response to mitoxantrone.

Assessment of morphometric measurements of prostate carcinoma volume.

The authors have shown that the primary determinants of prostate carcinoma progression are tumor volume and the percent of the tumor comprised of Gleason Grade 4/5 cells. In the current study the authors evaluated six different techniques for the morphometric measurements of prostate carcinoma volume. A computer-assisted image analysis (NIH Image, developed and maintained by the National Institutes of Health, Bethesda, MD) was used to analyze all 108 step-sectioned prostate specimens obtained between January 1 and December 31, 1997. The authors used the Stanford technique of 0.3-cm step-sections, measuring the volume of the tumor at both 0.3-cm and 0.6-cm intervals. The other 4 methods included the authors' previous method based on an earlier image program, the ellipsoidal method (pi / 6 x width x height x length), an estimation of the square area of the largest tumor, and the maximum tumor dimension (MTD). The authors first checked the accuracy of NIH Image analysis by measuring 24 circles of widely different sizes. The mean coefficient of variation was 1.7% and the correlation between the mean circle areas measured by the NIH Image software and true circle area essentially was perfect (correlation coefficient [r] = 1 and r(2) = 0.999; P < 0.0001). In comparison with the authors' original computer image program using 0.3-cm step-sections measured by a different observer, r(2) with the NIH Image analysis was 0.93. Using NIH Image only, the 0.6-cm step-section method missed measurable cancers in 16.7% of 108 radical prostatectomies in comparison with the 0.3-cm step-method. The mean tumor volume with the 0.6-cm section method (P < 0.0001) and the ellipsoidal method (P < 0.05) were significantly higher than with the 0.3-cm section method. r(2) from linear regressions using the 0.3-cm step section method as the standard versus the ellipsoidal method was 0.594, and was 0.89 versus the 0.6-cm step-section method, 0.652 versus the square area estimation, and 0. 527 versus the MTD method. The results of the current study support NIH Image as a powerful software program for the morphometric measurement of prostate carcinoma volume. Pathologic processing with 0.3-cm section slices was found to be more accurate for tumor volume than the 0.6-cm section slices. The ellipsoidal method, the square area of the largest tumor, and the MTD all were found to be inferior to computer-assisted image analysis measurements. In certain clinical situations in which only estimates of tumor volume are required, the square area of the largest tumor appears to be the best choice (r(2) 0.652).

Alteration of the cytoplasmic/nuclear expression pattern of galectin‐3 correlates with prostate carcinoma progression

Alteration of the cytoplasmic/nuclear expression pattern of galectin‐3 correlates with prostate carcinoma progression

Establishment of human prostate carcinoma skeletal metastasis models

BACKGROUND. Prostate carcinoma progression from an androgen dependent (AD) state to an androgen independent (Al) state occurs clinically in patients who undergo hormonal therapy. In their laboratory, the authors developed two human prostate carcinoma skeletal metastasis models, the LNCaP progression model and the ARCaP model, to investigate phenotypic and genotypic changes of prostate carcinoma cells during disease progression and to understand molecular pathways for potential therapeutic targeting. METHODS. LNCaP or ARCaP cells were inoculated in athymic mice and were exposed to selective hormonal conditions both in vivo and in vitro. The effects of various hormonal treatment regimens on tumor volumes and distant metastasis and the effects of bone stromal cells on prostate specific antigen (PSA) expression by prostate carcinoma cells were evaluated. RESULTS. The authors propose that prostate carcinoma progression from the AD state to the Al state assumes three AI phenotypes: AI that remains androgen responsive, AI that is unresponsive to androgen stimulation, and AI that is suppressed by or hypersensitive to androgen. AI prostate carcinoma cells interacted reciprocally with osteoblasts to produce enhanced tumor growth and osteoblastic reaction when they are deposited in bone. Bone stromal cell conditioned media stimulated prostate carcinoma cell growth and suppressed its PSA expression, as also evidenced by androgen receptor-mediated transactivation of PSA promoter reporter activity. Conditioned media obtained from prostate carcinoma cells also stimulated osteoblastic cell growth in vitro. A novel gene therapy strategy is being developed to target prostatic tumor epithelium and its supporting stroma using tissue specific and tumor-restricted, promoter-directed toxic gene expression in both cellular compartments. In addition, new strategies are being designed to target the tumor endothelial system in the stroma and tumor cell-extracellular matrix interaction mediated by isotype specific integrins. CONCLUSIONS. Prostate carcinoma skeletal metastasis models may prove useful in developing a new targeting strategy for the prevention and treatment of patients with prostate carcinoma.

Establishment of human prostate carcinoma skeletal metastasis models.

Prostate carcinoma progression from an androgen dependent (AD) state to an androgen independent (AI) state occurs clinically in patients who undergo hormonal therapy. In their laboratory, the authors developed two human prostate carcinoma skeletal metastasis models, the LNCaP progression model and the ARCaP model, to investigate phenotypic and genotypic changes of prostate carcinoma cells during disease progression and to understand molecular pathways for potential therapeutic targeting. LNCaP or ARCaP cells were inoculated in athymic mice and were exposed to selective hormonal conditions both in vivo and in vitro. The effects of various hormonal treatment regimens on tumor volumes and distant metastasis and the effects of bone stromal cells on prostate specific antigen (PSA) expression by prostate carcinoma cells were evaluated. The authors propose that prostate carcinoma progression from the AD state to the AI state assumes three AI phenotypes: AI that remains androgen responsive, AI that is unresponsive to androgen stimulation, and AI that is suppressed by or hypersensitive to androgen. AI prostate carcinoma cells interacted reciprocally with osteoblasts to produce enhanced tumor growth and osteoblastic reaction when they are deposited in bone. Bone stromal cell conditioned media stimulated prostate carcinoma cell growth and suppressed its PSA expression, as also evidenced by androgen receptor-mediated transactivation of PSA promoter reporter activity. Conditioned media obtained from prostate carcinoma cells also stimulated osteoblastic cell growth in vitro. A novel gene therapy strategy is being developed to target prostatic tumor epithelium and its supporting stroma using tissue specific and tumor-restricted, promoter-directed toxic gene expression in both cellular compartments. In addition, new strategies are being designed to target the tumor endothelial system in the stroma and tumor cell-extracellular matrix interaction mediated by isotype specific integrins. Prostate carcinoma skeletal metastasis models may prove useful in developing a new targeting strategy for the prevention and treatment of patients with prostate carcinoma.

Prostate carcinoma: production of bioactive factors.

Many molecular mechanisms regulate prostate carcinoma pathogenesis, proliferation, and progression to bone metastases. The basic molecular mechanisms are endocrine, paracrine, autocrine, and intracrine. These mechanisms can be mediated by a variety of agents, including gonadal and adrenal steroids, retinoic acid and vitamin D derivatives, neuroendocrine factors, growth factors, cytokines, lymphokine, and bone factors. Prominent among them is parathyroid hormone-related protein (PTHrP). The author studied the expression and regulation of PTHrP production in prostate carcinoma cells with nucleic acid and immunochemical probes for the polypeptide. The robust expression of this oncoprotein by prostate carcinoma has been demonstrated. In the current study the author reviews his results and the studies of other investigators regarding PTHrP and the variety of bioactive factors produced by prostate cells. PTHrP is expressed by most prostate carcinoma. It also is expressed by normal and hyperplastic prostate cells, and there is a gradient of expression that peaks in malignant prostate cells. PTHrP is processed by carcinoma cells into peptides that have unique biologic effects. Among them are regulation of growth and cytokine expression. It has been observed that the effect of PTHrP can be mediated by novel intracrine pathways in prostate carcinoma. These mechanisms influence transduction of growth regulatory signaling pathways, cell proliferation, immunoregulation, and angiogenesis. The current study identified PTHrP among the bioactive prostate factors that appear to participate in prostate carcinoma pathogenesis and progression. This oncofetal protein is commonly expressed by prostate carcinoma, and its regulatory interactions with other bioactive prostate cell products play an important role in the pathobiology of prostate carcinoma. Understanding these regulatory interactions among prostate carcinoma, its cell products, and the skeleton continues to provide insights into the pathogenesis of this disease entity and may provide clues to clinical management.

Tracking micrometastasis to multiple organs with lacZ-tagged CWR22R prostate carcinoma cells.

Metastasis to organs other than lung is rarely observed in animal model systems of human prostate carcinoma (PCA), with the exception of already metastatic isolates of human PCA cultured for long periods of time. To analyze more directly the evolution of metastatic variants from primary PCA tumor isolates, the lacZ histochemical marker gene was transfected into the CWR22Rv1 cell line isolated from the CWR22R xenograft (primary tumor). Three clones of varying lacZ-expression stability were analyzed for tumorigenicity and progression in athymic nude mice. Clones B and D were highly tumorigenic in the subcutis; however, lacZ expression was highly unstable. In contrast, clone H demonstrated highly stable lacZ expression for >25 passages in culture or in animals. Clone H, injected sc in a PBS vehicle, gave a 15-40% tumorigenic take. All primary tumor-bearing animals exhibited micrometastases in lung and other organs. Clone H injected in a Matrigel vehicle gave 100% tumorigenicity, with all animals displaying micrometastases in lung, liver, and/or bone (lower frequency in brain and kidney). Overall, the relative frequency of micrometastasis to multiple organs was lung>liver=bone>>brain>kidney. Overt metastases were never observed in the lung or bone but were occasionally found in liver. lacZ-transfected clone H CWR22Rv1 cells represent a much more accurate model of metastasis of PCA to the organs normally involved in progression of the human disease. Use of marker gene-tagged cells and other high-resolution molecular techniques will now permit analyses of the earliest events in PCA progression and micrometastasis.

Correlation of margin status and extraprostatic extension with progression of prostate carcinoma.

The correlation of surgical margins and extraprostatic extension (EPE) with progression is uncertain with regard to prostate carcinoma patients treated by radical prostatectomy. The objective of this study was to define factors predictive of cancer progression; emphasis was placed on surgical margins and their relation to extraprostatic extension. The study group consisted of 377 patients who were treated by radical retropubic prostatectomy and bilateral pelvic lymphadenectomy at the Mayo Clinic between 1986 and 1993. All specimens were totally embedded and whole-mounted. Patients ranged in age from 41 to 79 years (mean, 65 years). Those with seminal vesicle invasion or lymph node metastasis and those treated preoperatively with radiation or androgen deprivation were excluded. Final pathologic T classifications were pT2a (41 patients), pT2b (237), and pT3a (99). Progression was defined as biochemical failure (prostate specific antigen [PSA] >0.2 ng/mL), clinical or biopsy-proven local recurrence, or distant metastasis. The mean follow-up was 5.8 years (range, 0.2-11.4 years). Seventy-nine patients who received adjuvant treatment within 3 months after surgery were excluded from survival analysis. The overall margin positivity rate was 29%. Seventy-two patients (19%) had only positive surgical margins without evidence of EPE ("surgical incision"), 53 (14%) had only EPE, 37 (10%) had both, and 215 (57%) had neither. Positive margins were correlated with the finding of EPE (P = 0.003). Progression free survival rates at 5 and 10 years were 88% and 67%, respectively. In univariate analysis, preoperative PSA concentration, positive surgical margins, Gleason grade, cancer volume, and DNA ploidy were significant in predicting progression (P values, <0.001, <0.001, 0.01, 0.007, and <0.001, respectively). In multivariate analysis, margin status and DNA ploidy were independent predictors of progression (relative risk for margin status, 1.9; 95% confidence interval [CI], 1.1-3.4; P = 0.03; relative risk for DNA ploidy, 5.1; 95% CI, 2.4-10.9; P<0.001). Among patients with positive margins, 5-year progression free survival was 78% for those with negative EPE and 55% for those with positive EPE. Surgical margin status and DNA ploidy were independent predictors of progression after radical prostatectomy. To improve cancer control, adjuvant therapy may be considered for patients with positive surgical margins or nondiploid cancer.

CXC-chemokines stimulate invasion and chemotaxis in prostate carcinoma cells through the CXCR2 receptor.

Metastasis of prostate carcinoma requires invasion through the basement membrane, a thin extracellular matrix that underlies the epithelial cells, which must be breached by tumor cells invading into surrounding tissue. The CXC-chemokines, which have been shown to promote the migration of neutrophils and carcinoma cells, are candidates to influence prostate carcinoma-cell invasion. CXC-chemokines were examined for the ability to stimulate prostate cell line PC3 invasion in vitro through a reconstituted basement membrane and long-term migration and short-term adhesion to laminin, a major component of the basement membrane. PC3 cells responded to IL-8 and GROalpha with a 1. 6-2-fold increase in invasion through reconstituted basement membrane. A corresponding 2-3-fold increase in chemotaxis toward IL-8 and GROa was seen on laminin. Anti-CXCR2 antibody inhibited IL-8-stimulated migration. Expression levels of the beta(1) integrins were not changed by IL-8, and alpha(6beta1) integrin was used for both stimulated and baseline migration. In addition to the increases in migration and invasion, 2-6-fold transient increases in adhesion on laminin were seen with both IL-8 and GROalpha. These results suggest that the CXC-chemokines stimulate migration and invasion in part by altering the activation state of the beta(1) integrins. The CXC-chemokines act on prostate carcinoma cells through the CXCR2 receptor to promote behavior important for metastasis, and as such may be important in prostate carcinoma progression and metastasis.

Clinical significance of alterations of chromosome 8 in high-grade, advanced, nonmetastatic prostate carcinoma.

Chromosome 8 alterations, including loss of 8p21-22 and gain of 8q24, are commonly observed in prostate carcinoma. We examined whether these alterations are associated with poor prognosis in prostate cancer. We used dual-probe fluorescence in situ hybridization and DNA probes for 8p22 (lipoprotein lipase gene), centromere 8 (8cen), and 8q24 (c-myc gene) to determine the corresponding copy numbers in tumor samples from 144 patients with high-grade, advanced (stage III) prostate carcinoma. Cox models were used for multivariate analysis of systemic progression or patient death from prostate cancer. All statistical tests are two-sided. We classified the 8p22, 8cen, and c-myc copy number as normal, loss, and gain. An additional increase (AI) category of c-myc relative to the centromere copy number (i.e., overrepresentation and amplification of c-myc) was also used. Alterations of 8p22 were not statistically significantly associated with either systemic progression or patient death. Alterations of c-myc were associated with both systemic progression (P =.024) and patient death (P =.039); AI of c-myc showed the poorest outcome. We also evaluated the prognostic relevance of the combined 8p22-8cen-c-myc loci anomaly pattern for the following six patterns: normal-normal-normal, loss-any 8cen-normal, loss-gain-gain, gain-gain-gain, non-loss-any 8cen-AI, and loss-any 8cen-AI, where any 8cen is normal, loss, or gain of the chromosome 8 centromere. Patients with the loss-any 8cen-AI pattern had earlier systemic progression (P =.009) and earlier cause-specific death (P =.013) than did patients with other patterns. Multivariate analyses demonstrated that the loss-any 8cen-AI pattern was an independent risk factor for systemic progression (P<.001) and cause-specific death (P =.002). Genetic alterations of chromosome 8 appear to accumulate in parallel with the progression of prostate carcinomas. AI of the c-myc gene, especially with loss of 8p22, appears to be associated with poor patient prognosis.

Relationship of p21(WAF1) expression with disease-free survival and biochemical recurrence in prostate adenocarcinomas (PCa).

The p21(WAF1) gene is considered to be one of the major regulators of the cell cycle. Its level of expression has been shown to correlate with pathologic stage and Gleason score in prostatic cancer. However, its relationship to clinical outcome is not yet well-characterized. Immunohistochemical staining for p21(WAF1) protein expression was performed in 62 consecutive radical prostatectomy specimens from our institution. The results were correlated with the disease-free survival and biochemical recurrence of the patients. Thirty-four of the 62 patients were Caucasian and 28 were African American. There was a significant correlation between p21(WAF1) expression and biochemical recurrence after radical prostatectomy (P < 0.0095). However, while p21(WAF1) staining in prostate cancer was a prognostic indicator of disease-free survival in Caucasians (P < 0.0001), it appeared not to be a factor in African-American men (P = 0.908). This study suggests that p21(WAF1) may have a role in the pathogenesis and progression of prostate carcinoma, and may serve as a predictor of biochemical recurrence of this tumor. The differences in the values of p21(WAF1) as a prognostic marker of disease-free survival in Caucasians vs. African Americans suggest that progression of prostate cancer may have different mechanisms in different ethnic groups.

Relationship of p21WAF1 expression with disease‐free survival and biochemical recurrence in prostate adenocarcinomas (PCa)

BACKGROUND The p21WAF1 gene is considered to be one of the major regulators of the cell cycle. Its level of expression has been shown to correlate with pathologic stage and Gleason score in prostatic cancer. However, its relationship to clinical outcome is not yet well-characterized. METHODS Immunohistochemical staining for p21WAF1 protein expression was performed in 62 consecutive radical prostatectomy specimens from our institution. The results were correlated with the disease-free survival and biochemical recurrence of the patients. RESULTS Thirty-four of the 62 patients were Caucasian and 28 were African American. There was a significant correlation between p21WAF1 expression and biochemical recurrence after radical prostatectomy (P < 0.0095). However, while p21WAF1 staining in prostate cancer was a prognostic indicator of disease-free survival in Caucasians (P < 0.0001), it appeared not to be a factor in African-American men (P = 0.908). CONCLUSIONS This study suggests that p21WAF1 may have a role in the pathogenesis and progression of prostate carcinoma, and may serve as a predictor of biochemical recurrence of this tumor. The differences in the values of p21WAF1 as a prognostic marker of disease-free survival in Caucasians vs. African Americans suggest that progression of prostate cancer may have different mechanisms in different ethnic groups. Prostate 40:256–260, 1999. © 1999 Wiley-Liss, Inc.

Dedifferentiation in the metastatic progression of prostate carcinoma

BACKGROUND Dedifferentiation is a distinctive feature of cancer progression. Detailed histologic analysis of primary prostate carcinoma and synchronous lymph node metastases may improve our understanding of the complex process of cancer progression and metastasis. METHODS The authors studied 242 regional lymph node positive prostate carcinoma patients who underwent radical prostatectomy and bilateral lymphadenectomy between 1987 and 1992 at the Mayo Clinic. Patients ranged in age from 47–79 years (median, 66 years). The median follow-up was 6.1 years. Gleason scores of lymph node metastases and primary tumors were compared and correlated with systemic disease progression. Histologic dedifferentiation was defined as a higher Gleason grade in the lymph node metastases than in the primary tumor. Systemic disease progression was defined as the presence of distant metastases documented by biopsies, abdominal computed tomography, plain radiograph, or bone scan. RESULTS The 5-year systemic progression free survival (PFS) rate was 90%. The Gleason score in the lymph node metastases was higher than in the primary tumor in 45% of patients, lower in 12% of patients, and matched exactly in 43% of patients. The 5-year PFS was significantly different between patients with histologic dedifferentiation (88% ± 3) and those without dedifferentiation (94% ± 2) (P = 0.04). Adjusting for the Gleason grade of the primary tumor and total lymph node tumor volume, the relative risk for disease progression associated with dedifferentiation was 1.8 (95% confidence interval, 0.7–4.7; P = 0.25). CONCLUSIONS The findings of the current study demonstrate the morphologic heterogeneity of metastases from prostate carcinoma. There is a trend toward histologic dedifferentiation when prostate carcinoma metastasizes to regional lymph nodes. This dedifferentiation, although univariately significant, was not associated with disease progression when adjusted for lymph node tumor volume. Cancer 1999;86:657–63. © 1999 American Cancer Society.