Is active surveillance a suitable option for African American men with prostate cancer? A systemic literature review.

BACKGROUND: Certain patients presenting with either low or very-low-risk prostate cancer (PCa) can represent a therapeutic dilemma for physicians. The oncologic outcomes of active surveillance (AS) for men with very-low-risk PCa are overall excellent. However, there are concerns about AS related to the potential for upgrading or upstaging. The African American (AA) population is under-represented in studies evaluating AS outcomes and this is particularly important because of the unique epidemiology of PCa in AA men. METHODS: A literature review through the Medline database published from 1990 until August 2015 was performed to identify studies reporting outcomes of the AA population with low-risk PCa that underwent either AS or treatment. An additional search for studies on genetic mechanisms involved in development of PCa in AA men was also performed. RESULTS: Eleven studies on pathologic results of AA men who would qualify for AS were identified and in eight of these studies AA race was found to be associated with adverse pathological outcomes such as positive surgical margins, upgrading or upstaging. The other three studies reported no significance in these parameters with respect to race. Five more studies reported outcomes of AS in AA men with different study end points. AA men were mainly found to have a higher rate of disease reclassification subsequent to active treatment. The studies on genetic mechanisms also identified different genetic alterations in the AA population. CONCLUSIONS: AA men with clinically defined low-risk PCa may have either a higher grade or volume of cancer that was not detected on routine evaluation. Therefore, AS among such patients should be approached with caution. We recommend discussing such risks with AA patients with an acknowledgement that existing favorable outcomes noted in largely Caucasian populations may not be applicable to AA patients. We propose a modified evaluation plan for AA patients that includes an early confirmatory biopsy preceded by an magnetic resonance imaging to optimally detect occult cancer foci.

A randomized, double-blind, placebo-controlled study of the effects of pomegranate extract on rising PSA levels in men following primary therapy for prostate cancer.

BACKGROUND: The primary objective of this study was to compare the effects of pomegranate juice on PSA doubling times (PSADT) in subjects with rising PSA levels after primary therapy for prostate cancer. METHODS: Double-blind, placebo-controlled multi-institutional study, evaluated the effects of pomegranate liquid extract on serum PSA levels. The primary end point of this study was change in serum PSADT. Additional secondary and exploratory objectives were to evaluate the safety of pomegranate juice and to determine the interaction of manganese superoxide dismutase (MnSOD) AA genotype and pomegranate treatment on PSADT. RESULTS: One-hundred eighty-three eligible subjects were randomly assigned to the active and placebo groups with a ratio of 2:1 (extract N=102; placebo N=64; juice N=17). The majority of adverse events were of moderate or mild grade. Median PSADT increased from 11.1 months at baseline to 15.6 months in the placebo group (P<0.001) compared with an increase from 12.9 months at baseline to 14.5 months in the extract group (P=0.13) and an increase from 12.7 at baseline to 20.3 in the juice group (P=0.004). However, none of these changes were statistically significant between the three groups (P>0.05). Placebo AA patients experienced a 1.8 month change in median PSADT from 10.9 months at baseline to 12.7 months (P=0.22), while extract patients experienced a 12 month change in median PSADT from 13.6 at baseline to 25.6 months (P=0.03). CONCLUSIONS: Compared with placebo, pomegranate extract did not significantly prolong PSADT in prostate cancer patients with rising PSA after primary therapy. A significant prolongation in PSADT was observed in both the treatment and placebo arms. Men with the MnSOD AA genotype may represent a group that is more sensitive to the antiproliferative effects of pomegranate on PSADT; however, this finding requires prospective hypothesis testing and validation.

Integrating chemohormonal therapy and surgery in known or suspected lymph node metastatic prostate cancer.

BACKGROUND: Prostate cancer persisting in the primary site after systemic therapy may contribute to emergence of resistance and progression. We previously demonstrated molecular characteristics of lethal cancer in the prostatectomy specimens of patients presenting with lymph node metastasis after chemohormonal treatment. Here we report the post-treatment outcomes of these patients and assess whether a link exists between surgery and treatment-free/cancer-free survival. METHODS: Patients with either clinically detected lymph node metastasis or primaries at high risk for nodal dissemination were treated with androgen ablation and docetaxel. Those responding with PSA concentration <1 ng ml(-1) were recommended surgery 1 year from enrollment. ADT was withheld postoperatively. The rate of survival without biochemical progression 1 year after surgery was measured to screen for efficacy. RESULTS: Forty patients were enrolled and 39 were evaluable. Three patients (7.7%) declined surgery. Of the remaining 36, 4 patients experienced disease progression during treatment and 4 more did not reach PSA <1. Twenty-six patients (67%) completed surgery, and 13 (33%) were also progression-free 1 year postoperatively (8 with undetectable PSA). With a median follow-up of 61 months, time to treatment failure was 27 months in the patients undergoing surgery. The most frequent patterns of first disease recurrence were biochemical (10 patients) and systemic (5). CONCLUSIONS: Half of the patients undergoing surgery were off treatment and progression-free 1 year following completion of all therapy. These results suggest that integration of surgery is feasible and may be superior to systemic therapy alone for selected prostate cancer patients presenting with nodal metastasis.

Controversies in ilioinguinal lymphadenectomy.

Patients with penile cancer who are proven to have negative inguinal lymph nodes have an excellent prognosis. Furthermore, patients with small-volume inguinal node involvement can often be cured by surgery alone. Lymphadenectomy has clear survival benefits for patients when applied to those with lymph node metastasis. However, the current morbidity of the standard technique of lymphadenectomy is an impediment to its universal application, and innovative strategies to reduce the morbidity of staging/treatment that do not compromise oncologic control must be developed and standardized. The optimal integration of multimodality therapy to improve survival in advanced disease will occur only through collaborative studies between centers with significant patient volume, which would be facilitated through the development of regional referral centers.

A common nonsense mutation in EphB2 is associated with prostate cancer risk in African American men with a positive family history.

BACKGROUND: The EphB2 gene was recently implicated as a prostate cancer (PC) tumour suppressor gene, with somatic inactivating mutations occurring in approximately 10% of sporadic tumours. We evaluated the contribution of EphB2 to inherited PC susceptibility in African Americans (AA) by screening the gene for germline polymorphisms. METHODS: Direct sequencing of the coding region of EphB2 was performed on 72 probands from the African American Hereditary Prostate Cancer Study (AAHPC). A case-control association analysis was then carried out using the AAHPC probands and an additional 183 cases of sporadic PC compared with 329 healthy AA male controls. In addition, we performed an ancestry adjusted association study where we adjusted for individual ancestry among all subjects, in order to rule out a spurious association due to population stratification. RESULTS: Ten coding sequence variants were identified, including the K1019X (3055A-->T) nonsense mutation which was present in 15.3% of the AAHPC probands but only 1.7% of 231 European American (EA) control samples. We observed that the 3055A-->T mutation significantly increased risk for prostate cancer over twofold (Fisher's two sided test, p = 0.003). The T allele was significantly more common among AAHPC probands (15.3%) than among healthy AA male controls (5.2%) (odds ratio 3.31; 95% confidence interval 1.5 to 7.4; p = 0.008). The ancestry adjusted analyses confirmed the association. CONCLUSIONS: Our data show that the K1019X mutation in the EphB2 gene differs in frequency between AA and EA, is associated with increased risk for PC in AA men with a positive family history, and may be an important genetic risk factor for prostate cancer in AA.

Clinical characteristics of African-American men with hereditary prostate cancer: the AAHPC Study.

INTRODUCTION: The African-American Hereditary Prostate Cancer (AAHPC) Study was designed to recruit African-American families fulfilling very stringent criteria of four or more members diagnosed with prostate cancer at a combined age at diagnosis of 65 years or less. This report describes the clinical characteristics of a sample of affected AAHPC family members. METHODS: In all, 92 African-American families were recruited into the study between 1998 and 2002. Complete clinical data including age and PSA at diagnosis, number of affected per family, stage, grade, and primary treatment were available on 154 affected males. Nonparametric Wilcoxon two-sample tests and Fisher's exact test (two-tailed), were performed to compare families with 4-6 and >6 affected males with respect to clinical characteristics. RESULTS: The mean number of affected men per family was 5.5, with a mean age at diagnosis of 61.0 (+/-8.4) years. Age at diagnosis, PSA and Gleason score did not show significant differences between the two groups of families. Based on the Gleason score, 77.2% of affected males had favorable histology. Significantly, there were marked differences between the two groups in the frequency of node-positive disease (P=0.01) and distant metastases (P=0.0001). Radical prostatectomy was the preferred primary therapy for 66.2% of all affected men followed by 20.8% who chose radiation therapy. CONCLUSIONS: Our findings suggest that affected males who carry the highest load of genetic factors are at the highest risk for early dissemination of disease, thus efforts at early diagnosis and aggressive therapeutic approaches may be warranted in these families. Since the primary therapy choices in our study favored definitive treatment (87.0%) when compared to the 1983 and 1995 SEER data in which 28 and 64% received definitive treatment, respectively, it appears that affected African-American men in multiplex families may be demonstrating the reported psycho-social impact of family history on screening practices and treatment decisions for prostate cancer.

Interferon-alpha prevents selection of doxorubicin-resistant undifferentiated-androgen-insensitive metastatic human prostate cancer cells.

BACKGROUND: We determined whether treatment of metastatic prostate cancer cells with doxorubicin (DOX) and interferon-alpha (IFN-alpha) prevented the emergence of highly undifferentiated tumor cells. METHODS: The state of cell differentiation was determined by analysis of prostate-specific antigen (PSA), E-cadherin, keratin, and vimentin. RESULTS: Human prostate cancer LNCaP-LN3 cells growing in culture as multicell spheroids expressed higher levels of E-cadherin and E-cadherin-associated beta-catenin than LNCaP-LN3 cells growing as monolayers. Treatment of cells with DOX downregulated PSA, E-cadherin, and keratin, and upregulated expression of vimentin and vascular endothelial growth factor (VEGF) mRNA. While treatment of cells with IFN-alpha did not alter gene expression, the addition of IFN-alpha to cultures treated with DOX produced synergistic toxicity and abrogated the changes in gene expression observed in cells treated with DOX alone. CONCLUSIONS: Treatment with IFN-alpha and DOX should be further explored as a therapeutic strategy for androgen-insensitive prostate cancer.

Blockade of NF-kappaB activity in human prostate cancer cells is associated with suppression of angiogenesis, invasion, and metastasis.

Since the NF-kappaB/relA transcription factor is constitutively activated in human prostate cancer cells, we determined whether blocking NF-kappaB/relA activity in human prostate cancer cells affected their angiogenesis, growth, and metastasis in an orthotopic nude mouse model. Highly metastatic PC-3M human prostate cancer cells were transfected with a mutated IkappaBalpha (IkappaBalphaM), which blocks NF-kappaB activity. Parental (PC-3M), control vector-transfected (PC-3M-Neo), and IkappaBalphaM-transfected (PC-3M-IkappaBalphaM) cells were injected into the prostate gland of nude mice. PC-3M and PC-3M-Neo cells produced rapidly growing tumors and regional lymph node metastasis, whereas PC-3M-IkappaBalphaM cells produced slow growing tumors with low metastatic potential. NF-kappaB signaling blockade significantly inhibited in vitro and in vivo expression of three major proangiogenic molecules, VEGF, IL-8, and MMP-9, and hence decreased neoplastic angiogenesis. Inhibition of NF-kappaB activity in PC-3M cells also resulted in the downregulation of MMP-9 mRNA and collagenase activity, resulting in decreased invasion through Matrigel. Collectively, these data suggest that blockade of NF-kappaB activity in PC-3M cells inhibits angiogenesis, invasion, and metastasis.

Genetic abnormalities specifically associated with varying metastatic potential of prostate cancer cell lines as detected by comparative genomic hybridization.

Established recently are two in vivo prostate tumor progression models in which subclones of the PC3M and LNCaP cell lines were selected for varying growth characteristics and metastatic potential after successive orthotopic implantation in the prostate of nude mice. In this study, we used comparative genomic hybridization (CGH) to compare the chromosomal abnormalities between the parental cell lines and their respective variants and to determine if specific chromosomal abnormalities can be identified that are associated with different growth properties. PC3M and its derivative cell lines PC3M-Pro4 and PC3M-LN4 shared gains of 8q22--qter, 10q21--q22, and Xq27--qter and loss of 13q33--qter. PC3M-Pro4, a derivative line that produced significantly larger tumors in the prostate, had a unique gain of 3q13. In contrast, PC3M-LN4, the derivative line that produced significantly larger metastatic tumors in the lymph nodes and had higher incidences of distant metastases, had a specific gain of 1q21--q22 and losses of 10q23--qter and 18q12--q21. In the second in vivo model, LNCaP and its derivative cell lines shared gain of 3q27--qter and loss on 13q21--qter. The derivative line that produced significantly larger tumors in the prostate, LNCaP-Pro5, had a unique gain on 13q12--q13. In comparison, LNCaP-LN3, a derivative line that had a significantly higher incidence of lymph node metastases and produced significantly larger metastatic tumors in the lymph nodes, had specific losses of 16q23--qter and 21q. Interestingly, some regions of loss (e.g., 10q23-->qter, 16q23-->qter, and 18q12-->q21) detected in the variant cell lines correlated well with abnormalities seen in clinical prostate cancer cases. Thus, our data suggest not only that these cell lines are relevant in vivo models for prostate cancer progression, but also that CGH is a valuable tool for uncovering chromosomal regions that are important for aggressive growth and metastasis of prostate cancer cells.

Tumor stage, vascular invasion and the percentage of poorly differentiated cancer: independent prognosticators for inguinal lymph node metastasis in penile squamous cancer.

PURPOSE: We determine if histopathological factors of the primary penile tumor can stratify the risk of the development of inguinal lymph node metastases. MATERIALS AND METHODS: Clinical records of 48 consecutive patients with squamous cell carcinoma of the penis who underwent resection of the primary lesion and either inguinal lymph node dissection or were observed for signs of recurrence (median followup 59 months) were reviewed. Parameters examined included pathological tumor stage, quantified depth of invasion and tumor thickness, histological and nuclear grade, percentage of poorly differentiated cancer in the primary tumor, number of mitoses and presence or absence of vascular invasion. Variables were compared in 18 lymph node positive and 30 lymph node negative cases. RESULTS: Pathological tumor stage, vascular invasion and presence of greater than 50% poorly differentiated cancer were the strongest predictors of nodal metastasis on univariate and multivariate regression analyses. None of 15 pT1 tumors exhibited vascular invasion or lymph node metastases. Of 33 patients with pT2 or greater tumors 21 (64%) had vascular invasion and 18 (55%) had metastases. Only 4 of 25 patients (15%) with 50% or less poorly differentiated cancer in the penile tumor had metastases compared with 14 of 23 patients (61%) with greater than 50% poorly differentiated cancer (p = 0.001). No other variables tested were significantly different among the patient cohorts. CONCLUSIONS: Pathological stage of the penile tumor, vascular invasion and greater than 50% poorly differentiated cancer were independent prognostic factors for inguinal lymph node metastasis. Prophylactic lymphadenectomy in compliant patients with pT1 lesions without vascular invasion and 50% or less poorly differentiated cancer does not appear warranted.

African-American heredity prostate cancer study: a model for genetic research.

A genome-wide scan of high-risk prostate cancer families in North America has demonstrated linkage of a particular marker to Chromosome 1q (HPC1). An even greater proportion of African-American families have shown linkage to HPC1. Therefore, investigators at the National Human Genome Research Institute (NHGRI) in collaboration with Howard University and a predominantly African-American group of urologists established the African-American Hereditary Prostate Cancer (AAHPC) Study Network to confirm the suggested linkage of HPC in African Americans with a gene on Chromosome 1. Blood samples from recruited families were sent to Howard University for extraction of DNA. The DNA was sent to NHGRI at NIH where the genotyping and genetic sequence analysis was conducted. Genotype data are merged with pedigree information so that statistical analysis can be performed to establish potential linkage. From March 1, 1998, to June 1, 1999, a total of 40 African-American families have been recruited who met the study criteria. Preliminary results suggest that racial/ethnicity grouping may affect the incidence and extent of linkage of prostate cancer to specific loci. The importance of these findings lays in the future treatment of genetic-based diseases.

African-American heredity prostate cancer study: a model for genetic research.

A genome-wide scan of high-risk prostate cancer families in North America has demonstrated linkage of a particular marker to Chromosome Iq (HPC11. An even greater proportion of African-American families have shown linkage to HPC 1. Therefore, investigators at the National Human Genome Research Institute [NHGRI] in collaboration with Howard University and a predominantly African-American group of urologists established the African-American Hereditary Prostate Cancer (AAHPC) Study Network to confirm the suggested linkage of HPC in African Americans with a gene on Chromosome 1. Blood samples from recruited families were sent to Howard University for extraction of DNA. The DNA was sent to NHGRI at NIH where the genotyping and genetic sequence analysis was conducted. Genotype data are merged with pedigree information so that statistical analysis can be performed to establish potential linkage. From March 1, 1998, to June 1, 1999, a total of 40 African-American families have been recruited who met the study criteria. Preliminary results suggest that racial/ethnicity grouping may affect the incidence and extent of linkage of prostate cancer to specific loci. The importance of these findings lays in the future treatment of genetic-based diseases.

Relative expression of type IV collagenase, E-cadherin, and vascular endothelial growth factor/vascular permeability factor in prostatectomy specimens distinguishes organ-confined from pathologically advanced prostate cancers.

The tumor grade (Gleason score) in the biopsy and pretherapy prostate-specific antigen level do not accurately predict disease outcome of individual patients' prostate cancer. We used a rapid colorimetric in situ hybridization technique to evaluate the expression level of E-cadherin (which affects cell cohesion); matrix metalloproteinases (MMPs) types 2 and 9 (which affect invasion); and vascular endothelial growth factor/vascular permeability factor (which affects angiogenesis) in archival prostatectomy specimens from 40 patients. Intratumoral heterogeneity for gene expression (edge versus center versus perineural area) was more pronounced in advanced cancers than in those that were organ confined. Regardless of Gleason score, the highest expression level for E-cadherin was found in the center or perineural area of the tumors, whereas the highest expression levels for MMP-2 and MMP-9 were associated with the invasive edge. The relationship between advancing pathological stage and expression of all four metastasis-related genes was highly significant. Decreased expression of E-cadherin and increased expression of MMP-2, MMP-9, and vascular endothelial growth factor/vascular permeability factor were associated with the Gleason score of the tumors. Irrespective of serum prostate-specific antigen level or Gleason score, the ratio between expression of MMPs and E-cadherin at the invasive edge of tumors exhibited the strongest association with nonorgan-confined prostate cancer. These data suggest that the relative expression of metastasis-related genes in radical prostatectomy specimens can distinguish between organ-confined and advanced prostate cancers and provides the rationale for a prospective study correlating gene expression in pretherapy core biopsies with outcome.

Interleukin 8 expression regulates tumorigenicity and metastases in androgen-independent prostate cancer.

Interleukin 8 (IL-8) is mitogenic and chemotactic for endothelial cells. Within a neoplasm, IL-8 is secreted by inflammatory and neoplastic cells. The highly metastatic PC-3M-LN4 cell line overexpresses IL-8 relative to the poorly metastatic PC-3P cell line. We evaluated whether IL-8 expression by human prostate cancer growing within the prostate of athymic nude mice regulates tumor angiogenesis, growth, and metastasis. PC-3P cells were transfected with the full-length sense IL-8 cDNA, whereas PC-3M-LN4 cells were transfected with the full-sequence antisense IL-8 cDNA. Control cells were transfected with the neomycin resistance gene (Neo). In vitro, sense-transfected PC-3P cells overexpressed IL-8-specific mRNA and protein, which resulted in up-regulation of matrix metalloproteinase 9 (MMP-9) mRNA, and collagenase activity, resulting in increased invasion through Matrigel. After antisense transfection of the PC-3M-LN4 cells, IL-8 and MMP-9 expression, collagenase activity, and invasion were markedly reduced relative to controls. After orthotopic implantation, the sense-transfected PC-3P cells were highly tumorigenic and metastatic, with significantly increased neovascularity and IL-8 expression compared with either PC-3P cells or controls. Antisense transfection significantly reduced the expression of IL-8 and MMP-9 and tumor-induced neovascularity, resulting in inhibition of tumorigenicity and metastasis. These results demonstrate that IL-8 expression regulates angiogenesis in prostate cancer, in part by induction of MMP-9 expression, and subsequently regulates the growth and metastasis of human prostate cancer.

Neoadjuvant chemotherapy and hormonal therapy followed by radical prostatectomy: feasibility and preliminary results.

PURPOSE: We assessed the feasibility and efficacy of integrating chemotherapy and androgen ablation with radical prostatectomy in patients with locally advanced prostate cancer. The neoadjuvant approach was adopted because it allows an in situ assessment of antitumoral activity. PATIENTS AND METHODS: Thirty-three patients were enrolled who met the clinical criteria of stage T1-2, Gleason score of >/= 8 or T2b-T2c, Gleason score of 7 and prostate-specific antigen (PSA) level greater than 10 ng/mL (n = 15), or clinical stage T3 (n = 18). Therapy consisted of 12 weeks of ketoconazole and doxorubicin alternating with vinblastine, estramustine, and androgen ablation followed by prostatectomy. The ability of neoadjuvant chemotherapy and hormonal therapy to induce a 20% rate of pT0 in the prostatectomy specimen as well as surgical feasibility were assessed. RESULTS: Chemotherapy complications were comparable to those reported with this regimen previously. No major intraoperative complications occurred. Postoperative complications occurred in 10 (33%) of 30 patients. One patient died at home after discharge (postoperative day 17; no autopsy was performed). Ten (33%) of the 30 patients had organ-confined disease, and 20 (70%) of 30 had extraprostatic extension; 11 (37%) of the 30 had positive lymph nodes. Only five (17%) of 30 exhibited positive surgical margins. All patients achieved an undetectable PSA level postoperatively, and 20 of the surviving 29 patients remain without disease recurrence with a median follow-up of 13 months (range, 9 to 18 months). CONCLUSION: Chemotherapy and androgen ablation followed by radical prostatectomy was feasible in patients with locally advanced prostate cancer. Although the goal of achieving a 20% rate for pT0 status was not achieved, we believe this type of integrated therapeutic strategy should be investigated further for its ability to alter the course of regionally advanced prostate cancer.

Recruitment experience in the first phase of the African American Hereditary Prostate Cancer (AAHPC) study.

The African American Hereditary Prostate Cancer (AAHPC) Study is an ongoing multicenter genetic linkage study organized by Howard University and the National Human Genome Research Institute (NHGRI), with support from the Office for Research on Minority Health and the National Cancer Institute. The goals of the study are to: (i) look for evidence of involvement of chromosome 1q24-25 (HPC1) in African American men with hereditary prostate cancer (HPC) and (ii) conduct a genome-wide search for other loci associated with HPC in African American men. To accomplish these goals, a network has been established including Howard University, the NHGRI, and six Collaborative Recruitment Centers (CRCs). The CRCs are responsible for the identification and enrollment of 100 African American families. To date, 43 families have been enrolled. Recruitment strategies have included mass media campaigns, physician referrals, community health-fairs/prostate cancer screenings, support groups, tumor registries, as well as visits to churches, barber shops, and universities. By far, the most productive recruitment mechanisms have been physician referrals and tumor registries, yielding a total of 35 (81%) families. Approximately 41% (n = 3400) of probands initially contacted by phone or mail expressed interest in participating; the families of 2% of these met the eligibility criteria, and 75% of those families have been enrolled in the study, indicating a 0.5% recruitment yield (ratio of participants to contacts). As the first large-scale genetic linkage study of African Americans, on a common disease, the challenges and successes of the recruitment process for the AAHPC Study should serve to inform future efforts to involve this population in similar studies.

Highly metastatic human prostate cancer growing within the prostate of athymic mice overexpresses vascular endothelial growth factor.

Angiogenesis is essential for tumor progression and metastasis. It is mediated by the release of angiogenic factors by the tumor or host. We analyzed the expression of angiogenic factors by the prostate cancer cell line LNCaP and two derived variants, in vitro and in vivo, to determine whether metastatic cell lines express higher levels of these factors. The production of three angiogenic factors, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and interleukin 8 (IL-8), by LNCaP and its variants, LNCaP-LN3 (highly metastatic) and LNCaP-Pro5 (slightly metastatic), was measured by ELISA. VEGF, bFGF, and IL-8 mRNA expression was determined in vitro by Northern blot analysis. VEGF mRNA expression was determined in vivo by in situ hybridization. VEGF and flk-1 protein expression and microvessel density of LNCaP cell tumors were quantified by immunohistochemistry. In vitro, VEGF production by LNCaP-LN3 (3.15+/-0.04 pg/ml/10(3) cells) was significantly higher than those of both LNCaP (2.38+/-0.34 pg/ml/10(3) cells) and LNCaP-Pro5 (1.67+/-0.37 pg/ml/10(3) cells; P = 0.049 and 0.001, respectively). None of the three cell lines produced detectable levels of bFGF or IL-8 in vitro. In vivo, LNCaP-LN3 tumors exhibited higher levels of VEGF mRNA and protein (152.2+/-28.5 and 200.5+/-28.3) and of flk-1 protein (156.5+/-20.6) and had higher microvessel density (16.4+/-4.2) than either LNCaP tumors (89+/-17.5, 173.3+/-23.0, 124.6+/-21.6, and 12.4+/-3.5, respectively) or LNCaP-Pro5 tumors (63+/-14.7, 141.2+/-38.1, 126.1+/-20, and 5.8+/-2.2, respectively). In conclusion, metastatic human prostate cancer cells exhibited enhanced VEGF production and tumor vascularity compared with prostate cancer cells of lower metastatic potential. Thus, VEGF may play an important role in prostate cancer metastasis.

Suppression of angiogenesis, tumorigenicity, and metastasis by human prostate cancer cells engineered to produce interferon-beta.

We determined whether the IFN-beta gene can be used to suppress angiogenesis, tumor growth, and metastasis of human prostate cancer cells growing in the prostate of nude mice. Highly metastatic PC-3M human prostate cancer cells were engineered to constitutively produce murine IFN-beta subsequent to infection with a retroviral vector containing murine IFN-beta cDNA. Parental (PC-3M-P), control vector-transduced (PC-3M-Neo), and IFN-beta-transduced (PC-3M-IFN-beta) cells were injected into the prostate (orthotopic) or subcutis (ectopic) of nude mice. PC-3M-P and PC-3M-Neo cells produced rapidly growing tumors and regional lymph node metastases, whereas PC-3M-IFN-beta cells did not. PC-3M-IFN-beta cells also suppressed the tumorigenicity of bystander nontransduced prostate cancer cells. PC-3M-IFN-beta cells produced small tumors (3-5 mm in diameter) in nude mice treated with anti-asialo GM1 antibodies and in severe combined immunodeficient/Beige mice. Immunohistochemical staining revealed that PC-3M-IFN-beta tumors were homogeneously infiltrated by macrophages, whereas control tumors contained fewer macrophages at their periphery. Most tumor cells in the control tumors were stained positive by an antibody to proliferative cell nuclear antigen; very few were positively stained by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling. In sharp contrast, PC-3M-IFN-beta tumors contained fewer proliferative cell nuclear antigen-positive cells and many terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling-positive cells. Staining with antibody against CD31 showed that control tumors contained more blood vessels than PC-3M-IFN-beta tumors. PC-3M-IFN-beta cells were more sensitive to lysis mediated by natural killer cells in vitro or to cytostasis mediated by macrophages than control transduced cells. Conditioned medium from PC-3M-IFN-beta cells augmented splenic cell-mediated cytolysis to control tumor cells, which could be neutralized by antibody against IFN-beta. Collectively, the data suggest that the suppression of tumorigenicity and metastasis of PC-3M-IFN-beta cells is due to inhibition of angiogenesis and activation of host effector cells.

A feasibility study of cryotherapy followed by radical prostatectomy for locally advanced prostate cancer.

PURPOSE: There has been a significant shift toward multimodality therapy to try to eradicate extracapsular disease better in patients with locally advanced prostate cancer. We assess the feasibility and complications of initial cryotherapy followed by radical prostatectomy, and evaluate the frequency and location of viable benign and malignant prostate tissue and positive surgical margins after this treatment combination. MATERIALS AND METHODS: A total of 12 patients with clinical stage T3 cancer or clinical stages T1c to T2, Gleason score 8 to 10 cancer on the initial biopsy were treated with initial cryotherapy followed by open surgical exploration 2 to 8 days later. If pelvic lymph nodes were negative, radical prostatectomy was performed. Prostate specific antigen was measured approximately every 3 months postoperatively, and complications were assessed by retrospective chart review and a quality of life survey. RESULTS: Radical prostatectomy was aborted in 5 patients with positive pelvic lymph nodes. Of the 7 patients who underwent prostatectomy 4 had no residual prostate cancer in the specimen (pathological stage pT0 disease). All 7 of these patients had focal areas of viable normal prostate glands. Only 1 of the 7 patients had a positive surgical margin and biochemical failure (mean followup 22.6 months). The main complications of cryotherapy followed by radical prostatectomy were urinary incontinence and impotence. CONCLUSIONS: Neoadjuvant cryotherapy achieved complete tumor destruction in 4 of 7 patients with locally advanced prostate cancer. Cryotherapy followed by radical prostatectomy was associated with substantial morbidity, mainly in terms of urinary incontinence.