[Treatment strategy for elderly patients with prostate cancer]

Because of both the indolent and aggressive nature of prostate cancers, it is not easy to select the best treatment for elderly patients with a high prevalence of comorbidities. Since the growth of prostate cancer is generally slow and all treatments adversely affect the quality of life to some degree, conservative treatment may well be the best option for elderly patients with prostate cancer. In fact, previous studies have indicated that the rate of prostate cancer death was not high in patients with low-intermediate risk of prostate cancer who were treated conservatively. However, it is also true that we often encounter elder patients with a locally advanced cancer who had not been exposed to PSA screening. Previous reports also support aggressive treatment such as hormonal therapy, external radiation and brachytherapy alone or in combination for healthy elderly men with high-risk prostate cancer. Thus, after a careful evaluation of the nature of the cancer and comorbidity, we found that both conservative and aggressive treatments are applicable for elderly patients with prostate cancer to maintain their quality of life.

Safety and efficacy of docetaxel, estramustine phosphate and hydrocortisone in hormone-refractory prostate cancer patients

OBJECTIVE

To assess the combination of docetaxel (DTX), estramustine phosphate (EMP) and hydrocortisone for patients with hormone-refractory prostate cancer (HRPC).

METHODS

A total of 63 patients with HRPC were treated with a chemotherapeutic regimen including DTX, EMP, and hydrocortisone. Clinical and pathological features were correlated to serum prostate-specific antigen (PSA) recurrence and survival rates. Incidence and degree of toxicities were also retrospectively reviewed.

RESULTS

A median of 11 courses of chemotherapy was administered per patient. PSA levels decreased by >50% in 32 (51%) patients and >90% in 18 (29%) patients. Median time to PSA progression was 6 months (range from 1 to 41 months) and median time of overall survival was 14 months (range from 1 to 56 months). In a univariate analysis to predict overall survival, PSA, hemoglobin, alkaliphosphatase, and performance status prior to the chemotherapy were significant factors. Despite grade 3-4 neutropenia in 87% of patients, grade 5 interstitial pneumonia in one patient and grade 4-5 myocardial infarction in two patients were recognized, the regimen seemed to be relatively safe.

CONCLUSIONS

Combination chemotherapy with DTX, EMP and hydrocortisone provides survival benefits for patients with HRPC with an acceptable toxicity profile. We need to further evaluate who might benefit most from this regimen.

Primary seminoma of the prostate

Abstract A 54-year-old gentleman was suspected of having sarcoma of the prostate because of his low serum prostate-specific antigen level (1.9 ng/mL) and an enlarged heterogeneous mass on computed tomography and magnetic resonance imaging scans. Pathological examination of the prostate needle biopsy indicated seminoma, which was confirmed with immunohistochemical staining. There was no evidence of disease in other areas on physical examination or on radiographic tests. Therefore, we diagnosed the case as a primary seminoma of the prostate, which was consequently treated with a total of three courses of bleomycin, etoposide and cisplatin chemotherapy. Complete response was obtained on computed tomography, magnetic resonance imaging and prostate needle re-biopsy. To our knowledge, there have only been five cases of primary seminoma of the prostate reported.

Development and internal validation of a nomogram predicting extracapsular extension in radical prostatectomy specimens

OBJECTIVES

To present a nomogram predicting the side-specific probability of extracapsular extension (ECE) in radical prostatectomy (RP) specimens.

METHODS

Three hundred and fifty-four patients with T1c-T3a prostate cancer undergoing RP were included in the analysis. A receiver operating characteristic (ROC) analysis was carried out to evaluate the predictive values of each clinical and pathological factor, separately and in combination. Based on logistic regression analysis, a nomogram predicting the side-specific probability of ECE was developed.

RESULTS

Overall, 146 (40%) of 354 patients and 165 (23%) of 708 lobes had ECE pathologically. The areas under the ROC curve (AUC) of the standard features, such as serum PSA, clinical stage and biopsy Gleason sum on each side, in predicting side-specific probability of ECE were 0.624, 0.627, and 0.747, respectively. When these three features were combined, AUC increased to 0.773 which was not significantly different from 0.791 of maximum percent of cancer alone (P = 0.613) and significantly enhanced by including maximum percent of cancer on each side, 0.799 (P = 0.022). The resulting nomogram was internally validated and had excellent calibration.

CONCLUSIONS

The accuracy in predicting ECE is increased by combining standard clinical factors (clinical stage, serum PSA, highest Gleason score) and biopsy features, such as maximum percent of cancer in the cores. The developed nomogram is helpful when deciding whether or not neurovascular bundles can be preserved.

[Histopathologic changes due to combination of androgen deprivation and transurethral microwave thermotherapy in patients with localized prostate cancer]

Fifty patients with localized prostate cancer, clinical stage T1-T2N0M0 were studied. The therapy started with androgen deprivation therapy for 3 months to reduce the volume of prostate about 35%. High-energy transurethral microwave thermotherapy (TUMT) was then performed. Transurethral resection of the prostate (TURP) was performed in radical fashion at least 3 months after TUMT to confirm the treatment effect. Thorough pathological study of all the TURP chips revealed no cancer cells in 39 of the 50 patients. Among 11 patients who revealed remnant of cancer cells, 4 patients were with viable cancer cells, and 7 were with devitalized cancer cells.

[Biomarkers for prostate cancer in predicting diagnosis, staging and prognosis]

Recently, the incidence of prostate cancer in Japan has been markedly increased because of the aggressive use of serum PSA at urological clinics and/or screening. However, the limitations of serum PSA in diagnosis of prostate cancer are also well known. While the volume adjusted PSA, PSA isoforms and PSA kinetics are useful to improve the specificity of PSA in a diagnosis, their ability are still not enough to replace PSA. More importantly, there are no definitive markers to distinguish aggressive from indolent prostate cancers, and to predict outcomes after definitive therapies. With recent advances in biotechnology such as immunohistochemical staining, proteomics, tissue microarray, DNA microarray, FISH, ELISA, RT-PCR, and SELDI-TOF, many promising biomarkers have been identified and are currently under investigation and validation. However, it is unlikely that any one marker will predict perfectly the course of disease at present, so the use of nomograms that incorporate multiple predictive factors will be a realistic way to improve prostate cancer in screening and staging. We reviewed current and potential biomarkers for prostate cancer detection and staging.

ERK inhibitors as a potential new therapy for rheumatoid arthritis

Rheumatoid arthritis (RA), a chronic and systemic autoimmune disease that leads to progressive articular destruction, is evoked by the concerted action of RA-related cells, such as T cells, synovial fibroblasts and macrophages. Although anticytokine biologics block the intercellular signal transduction of these RA-related cells and thereby exert a strong ameliorative effect on RA, there still remains a significant percentage of nonresponsive patients. In addition to these biologics that disrupt specific intercellular signals, extracellular signal-regulated kinase (ERK) inhibitors, which are believed to target the intracellular signals common to the diverse RA-related cells, are also used as a treatment for RA patients, including those who are nonresponsive to the anticytokine therapies. Recently, potent and selective inhibitors for ERK with the co-crystal structures have been reported. FR180204, an ERK inhibitor, has been shown to be effective against mouse collagen-induced arthritis, a representative animal model of RA. This compound also suppresses the antigen-specific activation of T cells, which play a central role in the initiation and progress of the disease. Information obtained from the co-crystal structures would contribute to the improvement of the chemical characteristics. Thus, with the discovery of new potential chemical entities, ERK inhibitors may emerge as a new therapeutic approach for the treatment of RA.

Prognostic significance of tenascin-C expression in clear cell renal cell carcinoma

Tenascin-C is an extracellular matrix protein that plays an important role in cell proliferation, migration and tumor invasion in various types of cancer. However, few reports exist on tenascin-C expression in renal cell carcinoma (RCC). This study aimed to assess the prognostic significance of tenascin-C in clear cell RCC. Using immunohistochemistry, 137 formalin-fixed, paraffin-embedded tissue sections obtained from patients with clear cell RCC were examined for tenascin-C expression. Tenascin-C expression was observed in 55 (40.1%) of the 137 clear cell RCC sections. Tumor cells displayed membranous and/or cytoplasmic staining for tenascin-C. Tenascin-C expression was more prominent near the pseudocapsule of the tumor and around the tumor vessels. Tenascin-C expression was significantly associated with a higher stage (P=0.0065) and higher nuclear grade (P=0.0001). However, there was no correlation between the tenascin-C expression and venous involvement. The cancer-specific survival rate in patients with a tenascin-C-positive primary tumor was significantly lower than that in those with a tenascin-C-negative primary tumor in univariate analysis (P=0.0017). However, tenascin-C expression did not exhibit a significant value for cancer-related death in the Cox regression analysis. In patients with stage 1-3 disease, the 5-year metastasis-free rate in patients with the tenascin-C-positive primary tumor was significantly lower than that in those with the tenascin-C-negative primary tumor (67.8 vs. 88.5%, respectively; P=0.0038). The Cox regression analysis showed that tenascin-C expression is a significant predictor of metastasis (P=0.0345). The tenascin-C expression was strongly related to the stage, nuclear grade and 5-year metastasis-free rate. Therefore, tenascin-C expression may be a possible marker for the metastatic potential of clear cell RCC.

Characterization and gene expression analysis of novel matched primary and metastatic renal cell carcinoma cell lines

Despite recent advances in molecular biology that have clarified the mechanisms involved in the metastasis of several types of cancer, the molecular mechanism underlying the metastasis of renal cell carcinoma (RCC) remains unclear. Two RCC cell lines were successfully established from the surgical specimens of a matched primary tumor and adrenal metastasis from the same RCC patient, and were designated as TMK-1P and TMK-1M, respectively. Extensive characterization was accomplished using various methods, including the Matrigel invasion assay, DNA microarray analysis and real-time reverse transcriptase (RT)-polymerase chain reaction (PCR). While TMK-1P grew faster than TMK-1M, the invasive ability of TMK-1M was higher than that of TMK-1P. DNA microarray analysis showed a large differential expression of genes related to cell adhesion and the extracellular matrix molecules of which hexabrachion (tenascin-C), epidermal growth factor receptor, cadherin-6, and beta1-catenin were down-regulated, and the 67 kDa laminin receptor 1 and transforming growth factor-beta-induced 68 kDa protein (betaig-h3) were up-regulated in TMK-1M. Real-time RT-PCR analysis confirmed this differential gene expression between the two cell lines. The RCC cell lines may be useful in studying tumor invasion and screening markers for metastasis.

Do margins matter? The prognostic significance of positive surgical margins in radical prostatectomy specimens

PURPOSE

The prognostic significance of positive surgical margins (PSM) in radical prostatectomy (RP) specimens remains unclear. While most studies have concluded that a PSM is an independent adverse prognostic factor, others report that surgical margin status has no effect on prognosis. One reason for these discordant conclusions is the variable number of patients with a PSM who receive adjuvant therapy and the differing statistical methods used to account for the effects of the time course of adjuvant treatment on recurrence. We evaluated the prognostic significance of PSMs using multiple methods of analysis accounting for patients who received adjuvant therapy.

MATERIALS AND METHODS

We analyzed 1,389 consecutive patients with clinical stage T1-3 prostate cancer treated with RP by 2 surgeons from 1983 to 2000. Of 179 patients with a PSM, 37 received adjuvant therapy (AT), 29 radiation therapy and 8 received hormonal therapy. Because the method used to account for men receiving AT can affect the outcome of the analysis, data were analyzed by the Cox proportional hazards technique accounting for patients receiving AT using 5 methods: 1) exclusion, 2) inclusion (AT ignored), 3) censoring at time of AT, 4) failing at time of AT and 5) considering AT as a time dependent covariate.

RESULTS

Overall 179 patients (12.9%) had a PSM, including 6.8% of 847 patients with pT2 and 23% of 522 patients with pT3 disease. A PSM was a significant predictor of cancer recurrence when analyzed using methods 1, 3, 4 and 5 (p=0.005, p=0.014, p=0.0005, p=0.002, respectively). However, it was not a predictor of recurrence using method 2 in which AT was ignored (p=0.283). Using method 5 multivariate analysis demonstrated that a PSM (p=0.002) was an independent predictor of 10-year progression-free probability (PFP) along with Gleason score (p=0.0005), extracapsular extension (p=0.0005), seminal vesicle invasion (p <0.0005), positive lymph nodes (p <0.0005) and preoperative serum prostate specific antigen (p <0.0001). Using method 5 the 10-year PFP was 58% +/- 12% and 81% +/- 3% for patients with and without a PSM, respectively (p <0.00005). The relative risk of recurrence in men with a PSM using method 5 was 1.52 (95% confidence interval 1.06-2.16).

CONCLUSIONS

We confirm that a PSM has a significant adverse impact on PFP after RP in multivariate analysis using multiple statistical methods to account for patients who received AT. While prostate cancer screening strategies have resulted in a majority of men having organ confined disease at RP, surgeons should continue to strive to reduce the rate of positive surgical margins to improve cancer control outcomes.

[First 24 Japanese cases of robotic-assisted laparoscopic radical prostatectomy using the daVinci Surgical System]

In Japan, as of September 2007, prostatectomy is conducted with open surgical procedures in more than 90% of the cases. Following the first reported robotic prostatectomy by Binder, et al. in 2000, a robotic-assisted laparoscopic radical prostatectomy (RALP) using the daVinci Surgical System (Intuitive Surgical, Inc., Sunnyvale, California, USA) has been extensively used as a standard procedure with gratifying results in the United States. In the Asian region, in contrast, RALP is still in an introductory phase. Recently, we introduced RALP in Japan. A total of 24 patients received robotic surgery within a year since August 2006. RALP was completed in all patients without conversion to open surgery, except for the first patient in whom a restriction to a 2-hour operation had been imposed by the Ethical Committee. The mean operative time using the daVinci device and the mean estimated blood loss were 232.0 (range; 136-405) minutes and 313.0 (range; 10-1,000) ml, respectively. The training program we recently developed proved remarkably effective in reducing the learning curve of robotic surgery in Japan, where there is no person with expertise in this operating procedure. In particular, the intraoperative guidance given by the expert was useful after relevant problematic points were delineated by operators who received comprehensive video-based image training and actually performed robot surgery in several cases. With direct intraoperative guidance by the mentor during cases 13 and 14, both the operation time and estimated blood loss was markedly reduced.

Prognostic significance of location of positive margins in radical prostatectomy specimens

OBJECTIVES

Cancer at the resection margin is associated with an increased risk of biochemical recurrence after radical prostatectomy (RP) even after adjusting for other known clinical and pathologic risk factors. In this study, we assessed the prognostic significance of sites of positive surgical margins (+SMs) in RP specimens.

METHODS

We reviewed the data from 2442 patients with clinical Stage T1-T3 prostate cancer treated with RP from 1983 to 2004 who had had tumor maps generated from whole mount sections. The site of +SMs was assigned to six different areas (apex, bladder neck, seminal vesicle, anterior, posterolateral, and posterior).

RESULTS

Of the 2442 patients, 201 (8.2%) had a +SM at a single site and 74 (3.0%) had a +SM at multiple sites in the RP specimen. The posterolateral and apex sections were the most commonly involved sites for a +SM. Those with a +SM had a greater risk of biochemical recurrence than those with negative surgical margins (hazard ratio 1.39, 95% confidence interval 1.004 to 1.92; P = 0.047). We found that a +SM at the posterolateral site was significantly associated with an increased risk of biochemical recurrence (hazard ratio 2.80 for +SMs versus negative SMs at the posterolateral region; 95% confidence interval 1.76 to 4.44).

CONCLUSIONS

The effect on biochemical recurrence was influenced by the site of the +SM, with a posterolateral location having the most significant effect on prognosis. This heterogeneity of margin status has implications for predictive modeling, as well as the recommendation for adjuvant radiotherapy.

Significance of the craniocaudal distribution of cancer in radical prostatectomy specimens

OBJECTIVES

To examine the differences in the distribution of prostate cancer (PCa) in the craniocaudal dimension and their potential significance.

METHODS

We studied 1253 patients with clinically localized PCa treated with radical prostatectomy (RP) from 1983 to 2000. We analyzed the clinicopathological features according to the craniocaudal distribution (apex, mid, base) of the largest cancer focus.

RESULTS

Of these patients, 456 (36%) had the largest cancer focus in the apex, 728 (58%) in the mid, and 69 (6%) in the base. The cancers in the apex were less invasive than those in the mid or base, as evidenced by the lower frequency of extracapsular extension (27% vs 43%, 52%, respectively) and/or seminal vesicle involvement (5% vs 13%, 20%, respectively). The frequency of the largest cancer focus in the apex has increased significantly over time, from 26% before 1995 to 46% after 1995 (P < 0.001). Serum prostate specific antigen non-progression rate at 10 years for patients with a cancer at the apex was 83%, which was better than 76% and 77% of patients with a cancer at the mid or base (P = 0.029, P = 0.14, respectively).

CONCLUSION

The cancers dominant at the apex are increasing over time and represent half of the patients treated by RP in recent years. These cancers tend to be less aggressive compared to those in the mid or base of the prostate. This knowledge may be useful in understanding the biology of and maximizing the detection of PCa.

Highly Efficient Gene Delivery for Bladder Cancers by Intravesically Administered Replication-Competent Retroviral Vectors

PURPOSE

In an attempt to improve viral delivery of potentially therapeutic genes via an intravesical route, we have recently developed murine leukemia virus-based replication-competent retrovirus (RCR) vectors.

EXPERIMENTAL DESIGN

We evaluated the transduction efficiency of intravesically administered RCR vectors to bladder tumor using orthotopic animal models to determine their potential as delivery vectors for bladder cancer.

RESULTS

The RCR vector containing green fluorescent protein (GFP) marker gene achieved efficient in vitro transmission of the GFP transgene. Murine bladder tumor-2 mouse bladder tumors exposed to intravesically administered RCR vectors exhibited 0%, 9.2 +/- 2.9%, and 30.0 +/- 6.2% of GFP expression at 9, 18, and 27 days after exposure in the orthotopic model, respectively. Orthotopic KU-19-19 human bladder tumors exposed to intravesically administered RCR vectors exhibited 3%, 85 +/- 1.0%, and 100% of GFP expression at 7, 21, and 35 days after exposure, respectively. GFP staining was observed only in the tumor cells in the bladder. No detectable PCR products of GFP gene could be observed in distant organs. Treatment with RCR vectors containing yeast cytosine deaminase (CD) gene plus 5-fluorocytosine (5-FC) dramatically inhibited the growth of preestablished murine bladder tumor-2 tumors. A single course of 5-FC treatment resulted in a 50% animal survival in mice exposed to RCR-CD compared with a 0% survival in all controls over a 70-day follow-up period.

CONCLUSIONS

Intravesically administered RCR vectors can efficiently deliver genes to orthotopic bladder tumor without viral spread in distant organs. RCR-CD/5-FC suicide gene therapy promises to be a novel and potentially therapeutic modality for bladder cancer.

Prostate-specific antigen stimulates osteoprotegerin production and inhibits receptor activator of nuclear factor-kappaB ligand expression by human osteoblasts

BACKGROUND

Prostate cancer cells produce a large amount of prostate-specific antigen (PSA), which is widely used as a marker for this cancer. Even though it is widely used in the diagnosis of prostate cancer, many aspects of the pathophysiologic role of PSA in bone metastasis remain obscure. The receptor activator of nuclear factor-kappaB ligand (RANKL) is essential for the activation of osteoclasts, while osteoprotegerin (OPG) neutralizes the action of RANKL. Various substances that act on bone have been shown to modulate the production of RANKL and OPG by osteoblasts.

METHODS

In this study, we investigated the effect of PSA on the expression of OPG and RANKL mRNA and on protein production in human osteoblast-like cells.

RESULTS

After addition of PSA and culture for 72 h, OPG mRNA expression and protein secretion by MG-63 and SaOS-2 cells showed a concentration-dependent increase. When osteoblasts were incubated with PSA (100 ng/ml), OPG mRNA expression and protein secretion increased with the passage of time. alpha1 -antichymotrypsin (ACT), which inactivates the serine protease activity of PSA, inhibited the increase of OPG mRNA expression and protein production in response to PSA, and this effect of PSA was also inhibited by anti-transforming growth factor-beta antibody.

CONCLUSIONS

Based on our findings, PSA acts on human osteoblast-like cells via its own serine protease activity and promotes osteoblast differentiation. In addition, PSA stimulates OPG production and inhibits RANKL expression of osteoblasts, and inhibits bone resorption by osteoclasts, suggesting that it contributes to the characteristic osteoblastic features of bone metastases of prostate cancer.

Role of a cysteine residue in the active site of ERK and the MAPKK family

Kinases of mitogen-activated protein kinase (MAPK) cascades, including extracellular signal-regulated protein kinase (ERK), represent likely targets for pharmacological intervention in proliferative diseases. Here, we report that FR148083 inhibits ERK2 enzyme activity and TGFbeta-induced AP-1-dependent luciferase expression with respective IC50 values of 0.08 and 0.05 microM. FR265083 (1'-2' dihydro form) and FR263574 (1'-2' and 7'-8' tetrahydro form) exhibited 5.5-fold less and no activity, respectively, indicating that both the alpha,beta-unsaturated ketone and the conformation of the lactone ring contribute to this inhibitory activity. The X-ray crystal structure of the ERK2/FR148083 complex revealed that the compound binds to the ATP binding site of ERK2, involving a covalent bond to Sgamma of ERK2 Cys166, hydrogen bonds with the backbone NH of Met108, Nzeta of Lys114, backbone C=O of Ser153, Ndelta2 of Asn154, and hydrophobic interactions with the side chains of Ile31, Val39, Ala52, and Leu156. The covalent bond motif in the ERK2/FR148083 complex assures that the inhibitor has high activity for ERK2 and no activity for other MAPKs such as JNK1 and p38MAPKalpha/beta/gamma/delta which have leucine residues at the site corresponding to Cys166 in ERK2. On the other hand, MEK1 and MKK7, kinases of the MAPKK family which also can be inhibited by FR148083, contain a cysteine residue corresponding to Cys166 of ERK2. The covalent binding to the common cysteine residue in the ATP-binding site is therefore likely to play a crucial role in the inhibitory activity for these MAP kinases. These findings on the molecular recognition mechanisms of FR148083 for kinases with Cys166 should provide a novel strategy for the pharmacological intervention of MAPK cascades.

Delivery of replication-competent retrovirus expressing Escherichia coli purine nucleoside phosphorylase increases the metabolism of the prodrug, fludarabine phosphate and suppresses the growth of bladder tumor xenografts

We have developed unique replication-competent retroviral (RCR) vectors based on murine leukemia virus that provide improved efficiency of viral delivery, allow for long-term transgene expression and demonstrate an intrinsic selectivity for transduction of rapidly dividing tumor cells. The purpose of this study was to evaluate the in vivo transduction efficiency and the therapeutic efficacy of the RCR vector mediated delivery of Escherichia coli purine nucleoside phosphorylase (PNP) in combination with fludarabine phosphate for bladder cancer. We constructed vectors containing green fluorescent protein (GFP) gene (ACE)-GFP) or PNP gene (ACE-PNP). KU-19-19 bladder tumors exhibited 28.3+/-16.1, 46.6+/-5.8 and 93.7+/-7.8% of GFP expression on 14, 18 and 26 days after intratumoral injection of ACE-GFP, respectively. GFP expression could not be observed in normal tissues surrounding the injected tumors. No detectable polymerase chain reaction products of GFP gene could be observed in any distant organs. Intratumoral injection of ACE-PNP, followed by systemically administered fludarabine phosphate, significantly inhibited the growth of pre-established KU-19-19 tumors. Our results indicate that RCR vectors are a potentially efficient gene delivery method and that the RCR vector mediated PNP gene transfer and fludarabine phosphate treatment might be a novel and potentially therapeutic modality for bladder cancer.