Variation in the use of postoperative radiotherapy among high-risk patients following radical prostatectomy.

BACKGROUND: We used data from the Michigan Urological Surgery Improvement Collaborative (MUSIC) to investigate the use of adjuvant and salvage radiotherapy (ART, SRT) among patients with high-risk pathology following radical prostatectomy (RP). METHODS: For patients with pT3a disease or higher and/or positive surgical margins, we examined post-RP radiotherapy administration across MUSIC practices. We excluded patients with <6 months follow-up, and those that failed to achieve a postoperative PSA nadir ⩽0.1. ART was defined as radiation administered within 1 year post RP, with all post-nadir PSA levels <0.1 ng ml(-1). Radiation administered >1 year post RP and/or after a post-nadir PSA ⩾0.1 ng ml(-1) was defined as SRT. We used claims data to externally validate radiation administration. RESULTS: Among 2337 patients undergoing RP, 668 (28.6%) were at high risk of recurrence. Of these, 52 (7.8%) received ART and 56 (8.4%) underwent SRT. Patients receiving ART were younger (P=0.027), more likely to have a greater surgical Gleason sum (P=0.009), higher pathologic stage (P<0.001) and received treatment at the smallest and largest size practices (P=0.011). Utilization of both ART and SRT varied widely across MUSIC practices (P<0.001 and P=0.046, respectively), but practice-level rates of ART and SRT administration were positively correlated (P=0.003) with lower ART practices also utilizing SRT less frequently. Of the 88 patients not receiving ART and experiencing a PSA recurrence ⩾0.2 ng ml(-1), 38 (43.2%) progressed to a PSA ⩾0.5 ng ml(-1) and 20 (22.7%) to a PSA ⩾1.0 ng ml(-1) without receiving prior SRT. There was excellent concordance between registry and claims data κ=0.98 (95% CI: 0.94-1.0). CONCLUSIONS: Utilization of ART and SRT is infrequent and variable across urology practices in Michigan. Although early SRT is an alternative to ART, it is not consistently utilized in the setting of post-RP biochemical recurrence. Quality improvement initiatives focused on current postoperative radiotherapy administration guidelines may yield significant gains for this high-risk population.

A novel function for platelet-derived growth factor D: induction of osteoclastic differentiation for intraosseous tumor growth.

Although increasing evidence suggests a critical role for platelet-derived growth factor (PDGF) receptor ß (ß-PDGFR) signaling in prostate cancer (PCa) progression, the precise roles of ß-PDGFR and PDGF isoform-specific cell signaling have not been delineated. Recently, we identified the PDGF-D isoform as a ligand for ß-PDGFR in PCa and showed that PDGF-D is activated by serine protease-mediated proteolytic removal of the CUB domain in a two-step process, yielding first a hemidimer (HD) and then a growth factor domain dimer. Herein, we demonstrate that the expression of PDGF-D in human PCa LNCaP cells leads to enhanced bone tumor growth and bone responses in immunodeficient mice. Histopathological analyses of bone tumors generated by PDGF-D-expressing LNCaP cells (LNCaP-PDGF-D) revealed osteolytic and osteoblastic responses similar to those observed in human PCa bone metastases. Importantly, we discovered a novel function of PDGF-D in the regulation of osteoclast differentiation, independent of the RANKL/RANK signaling axis. Although both PDGF-B and -D were able to activate ß-PDGFR, only PDGF-D was able to induce osteoclastic differentiation in vitro, and upregulate the expression and nuclear translocation of nuclear factor of activated T cells 1, a master transcription factor for osteoclastogenesis. Taken together, these results reveal a new function of PDGF-D as a regulator of osteoclastic differentiation, an activity critical for the establishment of skeletal metastatic deposit in PCa patients.

Proliferation of prostate cancer cells in the bone marrow predicts recurrence in patients with localized prostate cancer.

BACKGROUND: Reverse-transcription polymerase chain reaction (RT-PCR) amplification of prostate specific antigen (PSA) mRNA has been used to detect the presence of prostate cancer cells in the peripheral blood and bone marrow of patients with clinically localized disease. Some studies have demonstrated a correlation between detection of PSA-mRNA and disease recurrence. However, many RT-PCR-positive patients remain disease-free. We propose that phenotypic characterization of individual micrometastatic cells may provide more prognostic information than mere detection of such cells. METHODS: We studied 58 patients undergoing radical prostatectomy for clinically localized disease whose bone marrow had been found to contain PSA-mRNA by RT-PCR. Immunohistochemical detection and phenotypic characterization of micrometastatic cells was performed using a two-color technique: cytokeratin antibody for detection and the MIB-1 antibody for proliferation. The clinical endpoint was disease recurrence. RESULTS: One or more micrometastatic cells were proliferating in 36.2% of the patients; the disease-free survival rate was 76.2% in this group. In contrast, in the patients with non-proliferating cells, 97.3% remained disease-free (P = 0.025). Multivariate analysis demonstrated that the presence of proliferating cells was the only preoperative variable that correlated with disease-free survival (P = 0.05). CONCLUSIONS: Determination of the phenotype of individual micrometastatic cells can contribute prognostic information above and beyond the mere determination of their presence or absence. Phenotypic characterization of individual micrometastatic cells may ultimately be used to select patients for systemic therapy given either alone or in combination with local therapy.

Mechanisms governing bone metastasis in prostate cancer.

Why does prostate cancer metastasize to bone? Why is there increased turnover of the bone matrix in the presence of prostate cancer? A recent autopsy study supports a traditional hypothesis that gross, anatomic patterns of blood flow influence the distribution of metastatic deposits. On the other hand, recent developments in animal models of prostate cancer bone metastasis have renewed interest in the traditional 'seed and soil' hypothesis: several studies point to specific biological interactions between prostate cancer cells and the bone microenvironment that can explain the tendency of prostate cancer cells to colonize bone and grow into clinically relevant metastatic deposits. Some studies implicate mechanisms including chemoattraction and enhanced adherence to bone endothelium. Additional data suggest that prostate cancer cells are 'osteomimetic', that is, they take on the properties and behaviors of osteoblasts or osteoclasts upon arrival in bone. These activities lead to enhanced turnover of the bone matrix and may explain the propensity of prostate cancer to grow in bone. Finally, a series of studies have implicated other molecular markers as distinguishing characteristics of bone-metastatic prostate cancer tissue.

Differential regulation of matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2 expression in co-cultures of prostate cancer and stromal cells.

Tumor-stromal interactions have been suggested to be a critical factor in both tumor invasion and tumor metastasis. Here, we examined the role of tumor-stromal interactions using co-cultures of prostate cancer (PC) cells derived from primary and metastatic tumors with primary or immortalized stromal (fibroblast and smooth muscle) cells and their effect on matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) expression. Co-cultures of PC and stromal cells showed enhanced levels of pro-MMP-9 and reduced levels of TIMP-1 and TIMP-2. Whereas enhanced expression of pro-MMP-9 occurred in PC cells, the TIMPs were down-regulated in stromal cells. Induction of pro-MMP-9 and reduction of TIMP expression did not require cell-cell contact and were mediated by a soluble factor(s) present in the conditioned medium of the effector cell. Collagen I is a potent inducer of pro-MMP-9 in PC cells. Consistently, preliminary characterization of the soluble factor in the fibroblast conditioned medium revealed m.w. of approximately 100 to 250 kDa, and its effect on pro-MMP-9 expression was partly inhibited by an anti-alpha2 integrin antibody, a major collagen I receptor. Expression of pro-MMP-9 protein and mRNA was also induced in metastatic PC-3 cells grown in human fetal bone implants in SCID mice. Together, these findings demonstrate the importance of tumor-stromal interactions in the regulation of MMP and TIMP expression and their potential role in PC progression.

Tissue inhibitor of metalloproteinase (TIMP)-2 acts synergistically with synthetic matrix metalloproteinase (MMP) inhibitors but not with TIMP-4 to enhance the (Membrane type 1)-MMP-dependent activation of pro-MMP-2.

The membrane-type 1 matrix metalloproteinase (MT1-MMP) has been shown to be a key enzyme in tumor angiogenesis and metastasis. MT1-MMP hydrolyzes a variety of extracellular matrix components and is a physiological activator of pro-MMP-2, another MMP involved in malignancy. Pro-MMP-2 activation by MT1-MMP involves the formation of an MT1-MMP.tissue inhibitors of metalloproteinases 2 (TIMP-2). pro-MMP-2 complex on the cell surface that promotes the hydrolysis of pro-MMP-2 by a neighboring TIMP-2-free MT1-MMP. The MT1-MMP. TIMP-2 complex also serves to reduce the intermolecular autocatalytic turnover of MT1-MMP, resulting in accumulation of active MT1-MMP (57 kDa) on the cell surface. Evidence shown here in Timp2-null cells demonstrates that pro-MMP-2 activation by MT1-MMP requires TIMP-2. In contrast, a C-terminally deleted TIMP-2 (Delta-TIMP-2), unable to form ternary complex, had no effect. However, Delta-TIMP-2 and certain synthetic MMP inhibitors, which inhibit MT1-MMP autocatalysis, can act synergistically with TIMP-2 in the promotion of pro-MMP-2 activation by MT1-MMP. In contrast, TIMP-4, an efficient MT1-MMP inhibitor, had no synergistic effect. These studies suggest that under certain conditions the pericellular activity of MT1-MMP in the presence of TIMP-2 can be modulated by synthetic and natural (TIMP-4) MMP inhibitors.

Stepwise genetic changes associated with progression of nontumorigenic HPV-18 immortalized human prostate cancer-derived cell line to a malignant phenotype.

Cytogenetics, fluorescence in situ hybridization (FISH), and comparative genomic hybridization (CGH) were used to identify genes that are involved in the development and progression of prostate cancer. For that purpose, we chose a cell line established in vitro from a prostatic adenocarcinoma which was nontumorigenic in nude mice and followed its progression to a tumorigenic cell line. Stepwise changes were observed in the cell line as it became tumorigenic. The composite karyotype at the nontumorigenic stage (CA-HPV-10) was 68 approximately 77,XXY,-(1, 9, 13, 14, 19, 22),+(4, 5, 11, 18, 20, 21),+(del(1) (q23q31)=M1 (two copies), +der(9)t(1;9)(q24 approximately q31;p23)=M5(two copies), der(14)t(14;?)(q10;?)=M17 in the majority of metaphases. These two derivative chromosomes were also observed a previous study. Our CGH analysis clearly showed that this deleted region in M1 is, in fact, translocated with derivative M5 and, in reality, is amplified. The cell line established from nodule (SCID 5019 p11), showed a number of new changes, as described; however, the most significant change was amplification of the 8q23 approximately qter region, harboring c-myc. This region was translocated with chromosomes 2, 4, and 16 as der(2)t(2;8)(q33;q23)=M12, der(4)t(4;8)(q34;q23)=M11, and der(16)t(8;16)(q24;q21)=M9. We deduce from our study that amplification of c-myc and other genes in the 8q23 approximately qter region were important in progression but did not lead to tumorigenicity. The population that became tumorigenic (SCID 5019 II) showed almost all of the same changes in the karyotype as observed in the nodular cell line; the only significant change was the appearance of der(11)t(4;11)(q32;q22)=M7 and the addition of another copy of t(3q;7p)=M2. These new changes lead to loss of chromosomes 3p, 4pter approximately q34, 6, 7q21 approximately qter, 11q22 approximately qter, and 18q, and gain of 3q, 7p, 8q23 approximately qter, and 11pter approximately q22, before the cell line became tumorigenic. The clonal selection of the population is proven by the presence of a number of the same derivative chromosomes in both the nodular and tumorigenic cell line. As it progressed to tumorigenicity, some of the same changes observed in the original study re-appear at different stages of malignancy, although it was absent in the nontumorigenic cell line. These are: der(16)t(8;16)(q24;q21)=M9 in the nodular cell line and der(11)t(4;11)(q32;q22)=M7 in the tumorigenic cell line. In our system, amplification of c-myc and other genes in der(2)t(2;8)(q33;q23)=M12,der(4) t(4;8)(q34;q23)=M11 together with the presence of der(16)t(8;16)(q24;q21)=M9 and der(11)t(4;11)(q32;q22)=M5 makes the cell line tumorigenic. It is either nontumorigenic, with the presence of a marker equivalent to der(16)=M9 and der(11)=M7 observed in the original study, and only nodular (SCID 5019 p11, present study), with the presence of number of markers with c-myc amplification (M9, M11, and M12). There is accumulation of all the above-mentioned changes in the same cell before it becomes tumorigenic.

Persistence of human vascular endothelium in experimental human prostate cancer bone tumors.

Using the SCID-human model, we recently found that human circulating prostate cancer cells formed tumors in human bone but not mouse bone (Nemeth et al. Cancer Res 1999; 59: 1987-93). It is possible that this tissue preference was mediated by interaction between human tumor cells and human endothelial cells within the implanted bone tissue. We sought to determine the relative amounts of human and mouse vasculature within human bone implants and resulting prostate cancer bone tumors in the SCID-human model. Paraffin sections of plain bone implants or PC3 or LNCaP human bone tumors were double stained for factor VIII (all vessels) and human CD31 (human vessels) followed by fluorescent secondary reagents. At 4 weeks post implantation (when cancer cells are typically introduced), the vasculature within human bone fragments remained primarily human (84.5%), and this pattern persisted to at least 10 weeks (91.6% human). Injection of PC3 cells into the bone resulted in an increase in mouse-derived vessels, however the majority (58%) of the vessels remained human even after the formation of large bone tumors. LNCaP bone tumors were highly angiogenic, and there was a sharp decline in the proportion of vessels which were antigenically human (36.8%), suggesting recruitment of mouse endothelial cells during the angiogenic process. Nonetheless, the persistence of human vasculature suggests the SCID-human model can be used to study the interaction between bone-seeking tumor cells, such as prostate cancer, and human bone endothelium in vivo, and to test potential therapeutic strategies which may depend on the presence of human vessels.

Cellular proliferation and prevalence of micrometastatic cells in the bone marrow of patients with clinically localized prostate cancer.

The presence of prostate cancer cells in the bone marrow (BM) of patients with clinically localized disease is associated with an increased chance of disease recurrence; however, not all patients develop recurrence. We therefore sought to determine the phenotype of individual micrometastatic cells as a potential method to better predict disease outcome. Immunostaining was performed on BM cells from 46 patients whose BM RNA fraction had been identified to contain prostate-specific antigen mRNA. The prevalence of micrometastatic cells among BM mononuclear cells was determined using an anticytokeratin antibody. Mib-1 antibody was used to determine the percentage of micrometastatic cells that were proliferating. Micrometastatic cells were found in 96% of patient samples, with a 30-fold variation in prevalence ranging from 0.1-3.26/10(5) BM cells. Prior androgen ablation was associated with a reduced prevalence of micrometastatic cells (P = 0.010). In 68% of patients, some micrometastatic cells were judged to be proliferating at proportions ranging from 1 of 11 (9%) to 4 of 4 (100%). Higher Gleason score of the primary tumor was associated with a higher proliferative proportion of micrometastatic cells (P = 0.038). We conclude that, in patients with clinically localized disease, there is wide variability in the prevalence of micrometastatic cells and the proportion which are proliferating. Long-term follow-up will determine whether the development of clinically obvious metastatic disease is related to higher prevalence of micrometastatic cells in the marrow or the proportion that are proliferating.

Isochromosome 8q formation is associated with 8p loss of heterozygosity in a prostate cancer cell line.

BACKGROUND: In advanced prostate cancer, loss of chromosomal regions on 8p is frequently associated with gain of 8q. We studied the gross chromosomal abnormalities associated with 8p loss of heterozygosity (LOH) in the prostate tumor cell line 1542 CP3Tx. The cell line was previously established from a primary prostatic adenocarcinoma by immortalization with a recombinant retrovirus carrying the E6 and E7 genes of human papilloma virus type 16. Allelotyping studies demonstrated LOH at multiple markers on 8p. METHODS: To investigate the relationship of 8p LOH to gross chromosomal rearrangements, and to screen for other genetic abnormalities in 1542 CP3Tx, we used comparative genomic hybridization (CGH), conventional karyotyping, fluorescence in situ hybridization (FISH), and allelotyping. RESULTS: CGH revealed loss of the entire 8p arm, associated with gain of the entire 8q arm. Other abnormalities included chromosome 4 loss and chromosome 11 gain. The karyotype showed an isochromosome (8q), monosomy 4, and trisomy 11. FISH and allelotyping confirmed and extended these results. CONCLUSIONS: These results demonstrate that i(8q) formation is a mechanism for associated 8p loss and 8q gain in prostate cancer. Furthermore, the small number of chromosomal abnormalities in this cell line indicates that immortalization of low-passage cultures with viral oncogenes provides a method for obtaining cell lines for studying genetic abnormalities in prostate cancer.

Prospects of immunotherapy for the treatment of prostate carcinoma--a review.

The treatment of prostate carcinoma is dependent on the stage of the disease. Patients who present with clinically localized cancer or locally advanced tumors can be potentially cured by radical prostatectomy, radiation, and hormonal therapy. However, disease progression can occur in 30-50% of patients diagnosed with clinically localized cancer. The bone is the predominant site of metastases. Metastatic prostate cancer is first treated by androgen blockade but within a few months becomes hormone refractory. Hormone refractory metastatic prostate cancer is not responsive to conventional treatments, and patients have an expected survival of less than a year. It is essential to develop new approaches for the treatment of hormone refractory metastatic disease. Immunotherapy, based on enhancement of the host immune response against the tumor, has been used as an alternative therapy for the treatment of metastatic cancers refractory to conventional therapy in particular for melanoma and renal cell carcinoma. In this review, we will summarize various immunotherapeutic approaches developed over the last 18 years, and we will address the potential of immunotherapy for the treatment of metastatic prostate carcinoma by reviewing preclinical studies and initial clinical trials performed in this field.

Severe combined immunodeficient-hu model of human prostate cancer metastasis to human bone.

Commonly used in vivo models of prostate cancer metastasis include syngeneic rodent cancers and xenografts of human cancer in immunodeficient mice. However, the occurrence of osseous metastases in these models is rare, and in xenograft models, species-specific factors may limit the ability of human cells to metastasize to rodent bones. We have modified the severe combined immunodeficient (SCID)-human model to test the ability of circulating human prostate cancer cells to home to macroscopic fragments of human bone and other organs previously implanted into SCID mice. We have also compared the growth of human prostate cancer cells in various human and mouse tissue microenvironments in vivo. Macroscopic fragments of human fetal bone, lung, or intestine (16-22 weeks gestation) or mouse bone were implanted s.c. into male CB.17 SCID mice. Four weeks later, human prostate cancer cells were injected either i.v. via the tail vein (circulating cell colonization assay) or directly into the implanted tissue fragments transdermally (end organ growth assay). Tumor growth was followed for 6 weeks by palpation and magnetic resonance imaging. After 6 weeks, tumors were enumerated in implanted human and mouse organ fragments and native mouse tissue. Tumors were characterized by histology, immunohistochemistry, and chromosomal analysis. After i.v. injection, circulating PC3 cells successfully colonized implanted human bone fragments in 5 of 19 mice. Tumors were easily followed by palpation and imaging and had an average volume of 258 mm3 at autopsy. Histological examination revealed osteolysis and a strong desmoplastic stromal response, which indicated intense stromal-epithelial interaction. Bone tumors were subcultured, and chromosomal analysis demonstrated that the tumors were derived from the parental prostate cancer cell line. Microscopic tumor colonies were also found in a few mouse lungs after i.v. injection of PC3, DU145, and LNCaP cells, however the volume of the lung nodules was less than 1 mm3 in all of the cases. No colonization of human lung or intestine implants, the mouse skeleton, or other mouse organs was detected, demonstrating a species- and tissue-specific colonization of human bone by PC3 cells. Direct injection of 10(4) prostate cancer cells into human bone implants resulted in large tumors in 75-100% of mice. PC3 and DU145 bone tumors were primarily osteolytic, whereas LNCaP bone tumors were both osteoblastic and osteolytic. PC3 and LNCaP bone tumors showed a desmoplastic stromal response, which indicated intense stromal-epithelial interaction. All three of the cell lines formed tumors in implanted human lung tissue; however, the tumors were all < or = 10 mm3 in volume and showed minimal stromal involvement. No tumors formed after either s.c. injection or injection of cells into implanted mouse bone demonstrating both species- and tissue-specific enhancement of growth of human prostate cancer cells by human bone. The severe combined immunodeficient-human model provides a useful system to study species-specific mechanisms involved in the homing of human prostate cancer cells to human bone and the growth of human prostate cancer cells in human bone.

Chromosomal analysis of renal angiomyolipoma by comparative genomic hybridization: evidence for clonal origin.

Angiomyolipoma has long been considered a hamartomatous polyclonal proliferation. However, recent molecular analyses have indicated that these tumors may be clonal neoplasms rather than polyclonal proliferations. We investigated chromosomal imbalances in angiomyolipoma by comparative genomic hybridization. DNA was extracted from archival paraffin-embedded and frozen tissues of 12 angiomyolipomas (10 usual variant, two epithelioid variant). The 10 angiomyolipomas of the usual variant included bilateral tumors from one tuberous sclerosis patient. Fluorescence ratio distributions from tumor hybridizations were compared with those from control hybridizations to detect changes in DNA copy number with high sensitivity and specificity. We identified 20 chromosomal imbalances in seven sporadic angiomyolipomas, including both tumors of the epithelioid variant. The remaining five tumors, including the two angiomyolipomas from a tuberous sclerosis patient, were devoid of chromosomal imbalances. Seventy-five percent of the imbalances were partial or whole chromosomal deletions involving disparate genomic regions, some of which have previously been associated with tumors of adipose tissue and smooth muscle tumors. Four angiomyolipomas of the usual variant showed 5q deletions with a common region of deletion spanning 5q33 to q34. In two tumors, deletion on 5q was the sole abnormality. One epithelioid angiomyolipoma showed 5q gain encompassing the same region in addition to other alterations. We concluded that (1) Chromosomal imbalances are common in renal angiomyolipomas; (2) Presence of clonal genomic alterations lends further support to the neoplastic pathogenesis of these tumors; (3) The 5q33-q34 region may contain a tumor suppressor gene significant in the histogenesis of some renal angiomyolipomas.

Membrane type 1-matrix metalloproteinase (MT1-MMP) and MMP-2 immunolocalization in human prostate: change in cellular localization associated with high-grade prostatic intraepithelial neoplasia.

Membrane type 1-matrix metalloproteinase (MT1-MMP) is a known activator of latent MMP-2 (pro-MMP-2), and increased MMP-2 expression has been associated with tumor aggressiveness in prostate cancer. However, expression of MT1-MMP in human prostate tissue has not been described. We investigated the expression and immunolocalization of MT1-MMP and MMP-2 in the epithelial components of benign prostate epithelium, high-grade prostatic intraepithelial neoplasia (HGPIN), and prostate cancer. Tissue sections from the peripheral zone of 50 prostates (radical prostatectomy specimens) were chosen based on their containing benign glands, HGPIN, and prostate cancer glands. All 50 sections were immunostained for MT1-MMP and MMP-2 and were evaluated for staining pattern, uniformity, and intensity. Western blotting and gelatin zymography were done to confirm expression of MT1-MMP and activity of MMP-2, respectively. Comparisons were made between benign epithelium, HGPIN, and cancer. In benign glands, basal cells (BCs) uniformly stained intensely for MT1-MMP, whereas secretory cells (SCs) were rarely positive (P < 0.0001). Conversely in HGPIN, SCs showed consistent cytoplasmic staining (P < 0.0001). In cancer cells, staining was heterogeneous and varied from no staining to very intense staining in select glands. MMP-2 in normal tissue stained both BCs and the apical region of SCs, whereas in HGPIN, staining was observed in the SC in a predominantly cytoplasmic pattern. Similar to MT1-MMP, staining in cancer tissue for MMP-2 was heterogeneous; however, there was a significant association between the pattern of MMP-2 and MT1-MMP staining within the epithelial components of the cancer glands in individual specimens (P < 0.001). Finally, MMP-2 and MT1-MMP were confirmed to be expressed in the prostate tissues by gelatin zymography and Western blotting. In conclusion, we found that consistent changes in localization and intracellular distribution of MMP-2 and MT1-MMP were associated with the transition from benign prostate epithelium to HGPIN, suggesting that regulation of these enzymes is altered during the earliest stages of prostate cancer.

Effect of neoadjuvant androgen deprivation on circulating prostate cells in the bone marrow of men undergoing radical prostatectomy.

Our objective was to determine the effect of neoadjuvant hormonal therapy on the presence of circulating prostate cells in patients undergoing radical prostatectomy for prostate cancer. A total of 60 patients at high risk for extraprostatic disease were analyzed for the presence of circulating prostate cells using reverse transcriptase PCR (RTPCR) amplification of the prostate-specific antigen mRNA. Twenty-nine patients underwent radical prostatectomy for a clinical T2b-c tumor or a stage T1c-T2a tumor and a serum prostate-specific antigen level > or =10ng/ml (radical prostatectomy alone), and 31 similarly staged patients received neoadjuvant hormonal therapy before radical prostatectomy (neoadjuvant). Bone marrow samples were used for RTPCR analysis. Twenty-four percent and 58% of the radical-prostatectomy-alone patients and neoadjuvant patients had organ-confined disease, respectively (P = 0.007). In the radical-prostatectomy-alone group, 77% and 14% of patients with extraprostatic and organ-confined disease were RTPCR positive, respectively (P = 0.03). However, in the neoadjuvant group, 46% and 28% of patients with extraprostatic and organ-confined disease were RTPCR positive, respectively (P = 0.29). For patients that were RTPCR positive, 45 % of the neoadjuvant patients had organ-confined disease compared with 6% in the radical-prostatectomy-alone patients (P = 0.018). These data suggest that a subset of the neoadjuvant patients are converted to organ confined disease without eliminating the prostate cells in the bone marrow. Our data suggest that hormonal therapy before radical prostatectomy decreases the occurrence of extraprostatic disease but, to a lesser degree, the incidence of circulating prostate cells. This may partially explain why hormonal therapy before radical prostatectomy has not improved disease-free survival.

Limited role of radionuclide bone scintigraphy in patients with prostate specific antigen elevations after radical prostatectomy.

PURPOSE: Bone scintigrams of patients with increasing serum prostate specific antigen (PSA) after radical prostatectomy are only rarely positive. We identify clinical parameters that would improve our ability to select patients for this imaging study. MATERIALS AND METHODS: We reviewed all bone scintigrams done at our institution between 1991 and 1996 in patients with persistently increasing serum PSA after radical prostatectomy. What prompted the clinician to obtain the bone scintigram was trigger PSA (tPSA). The rate of increase in PSA to tPSA was measured by tPSA/time from radical prostatectomy (slope 1) and tPSA/time from last undetectable PSA (slope 2). These parameters were evaluated together with standard clinicopathological data in univariate and multivariate analyses to determine the ability to predict the bone scintigram result. RESULTS: In univariate analysis tPSA (p = 0.003), slope 1 (p = 0.005) and slope 2 (p = 0.004) were useful in predicting the bone scintigram result but pathological stage, Gleason score, preoperative PSA and time to recurrence were not. In multivariate analysis the single most useful parameter in predicting the bone scintigram result was tPSA (p = 0.01). Based on a logistic regression model the probability of a positive bone scintigram was less than 5% until tPSA increased to 40 to 45 ng./ml. CONCLUSIONS: In patients with increasing serum PSA after radical prostatectomy current serum PSA is the best predictor of the bone scintigram result. Furthermore, there is limited usefulness of bone scintigraphy until PSA increases above 30 to 40 ng./ml.

Systemic interleukin 2 therapy for human prostate tumors in a nude mouse model.

Once the regional lymph nodes become involved in prostate carcinoma, 85% of patients develop distant metastases within 5 years, and metastatic disease is difficult to treat. We have investigated the effect of systemic interleukin 2 (IL-2) treatment on metastatic prostate carcinoma using a xenograft tumor model. Cells from a PC-3/IF cell line, produced by intrafemoral injection of human PC-3 prostate carcinoma cells, were injected in the prostate of Balb/c nude mice. Prostate tumors and para-aortic lymph nodes were resected, and tumor cells were recultured and passaged in the prostate in vivo to produce new cell lines. On day 6 following prostatic injection of these cell lines, mice were treated with i.p. injections of IL-2 at 25,000-50,000 units/ day for 5 consecutive days. The effect of IL-2 on tumor progression was assessed, and histological studies were performed on prostate tumor and lymph node sections. The tumor cell lines generated by serial prostate injection were tumorigenic and metastasized to regional para-aortic lymph nodes. Tumors of 0.4 cm were obtained by day 16 and grew to 1-1.5 cm by day 40 with metastasis to para-aortic lymph nodes. Following two to three weekly courses of 5 days of 25,000-40,000 units/day of IL-2, the growth of prostate tumors was inhibited by 94%. Higher doses of 50,000 units/ day were toxic. Histologically, prostate sections showed vascular damage manifested by multifocal hemorrhages and an influx of lymphocytes and polymorphonuclear cells into disintegrating tumors and areas of necrosis containing numerous apoptotic cells. In contrast to control mice, para-aortic lymph nodes were not enlarged in responding mice. These findings suggest that systemic IL-2 therapy can induce an antitumor response in prostate tumors and control their growth and metastasis.

Predictors for maximal outcome in patients undergoing salvage surgery for radio-recurrent prostate cancer.

OBJECTIVES: To determine preradiation and preoperative clinical staging and postoperative pathologic factors that can predict disease-free survival in patients undergoing salvage surgery for radio-recurrent prostate cancer. METHODS: A retrospective review was performed on 40 patients who underwent salvage surgery for radio-recurrent prostate cancer. Preradiation and preoperative clinical staging factors, as well as pathologic stage were analyzed as predictors of disease-free survival. Biochemical failure was defined as a persistent serum prostate-specific antigen (PSA) elevation greater than 0.4 ng/mL. RESULTS: As a group, salvage surgery provided excellent clinical disease control in 35 of 40 patients (87.5%). Overall, 18 of 38 (47.4%) patients analyzed had no evidence of biochemical progression. Preradiation clinical stage and pathologically organ-confined disease were statistically significant predictors of disease-free survival (P = 0.03 and P = 0.02, respectively). Seminal vesicle invasion and positive lymph nodes were the worst pathologic prognostic factors. Preoperative clinical T1c disease approached statistical significance in predicting pathologically organ-confined disease and disease-free survival (P = 0.08 and P = 0.07, respectively). CONCLUSIONS: Ideal candidates for salvage surgery should have preradiation and preoperative clinically organ-confined disease. All patients with pathologically organ-confined disease following salvage prostatectomy were disease free at a mean follow-up of 36.1 months. Salvage surgery, although technically feasible, should not be widely advocated as an effective curative treatment in patients with locally advanced disease at the time of diagnosis.