Takefumi Satoh

Transrectal high-intensity focused ultrasound for treatment of patients with stage T1b-2n0m0 localized prostate cancer: a preliminary report

OBJECTIVES To present our preliminary clinical results of transrectal high-intensity focused ultrasound (HIFU) in Stage T1b-2N0M0 prostate cancer. Efforts are being made to provide minimally invasive alternative treatment options with equal efficacy and fewer side effects. HIFU delivers ultrasound energy with rapid thermal necrosis of tissue in the focal region without damaging the surrounding tissue. METHODS We performed 28 HIFU treatments in 20 patients with biopsy-proven localized prostate cancer using a modified Sonablate-200 HIFU device. All patient characteristics and the clinical outcome of 20 patients followed up more than 6 months (mean 13.5) were analyzed. RESULTS A complete response was obtained in 100% (20 of 20) of patients, as evidenced by a negative postoperative prostate biopsy and no elevation on three successive prostate-specific antigen (PSA) determinations. Of the 20 patients, 13 (65%), 5 (25%), and 2 (10%) had PSA nadirs of less than 0.50 ng/mL, 0.50 to 1.00 ng/mL, and 1.01 to 2.00 ng/mL, respectively. Rectourethral fistula and urethral stricture were noted in 1 and 2 patients, respectively, and 1 patient underwent transurethral resection of the prostate because of prolonged urinary retention. CONCLUSIONS Our results show that HIFU can be performed without an incision, with a less severe side effect profile, and, unlike most other prostate treatments, is repeatable. Transrectal HIFU may be a useful option for patients with localized prostate cancer. Its long-term efficacy will be determined by additional follow-up and a Phase II trial.

Treatment of localized prostate cancer using high-intensity focused ultrasound

To evaluate the biochemical disease‐free survival (DFS), predictors of clinical outcome and morbidity of patients with localized prostate cancer treated with high‐intensity focused ultrasound (HIFU), a noninvasive treatment that induces complete coagulative necrosis of a tumour at depth through the intact skin.

Five years experience of transrectal high-intensity focused ultrasound using the Sonablate device in the treatment of localized prostate cancer

Background:  High‐intensity focused ultrasound (HIFU) is a minimally invasive technique used in achieve coagulation necrosis. We evaluated biochemical disease‐free survival rates, predictors of clinical outcome and morbidity in patients with localized prostate cancer treated with HIFU.

Prostate-Specific Antigen Response and Systemic T Cell Activation After In Situ Gene Therapy in Prostate Cancer Patients Failing Radiotherapy

In an extended phase I/II study we evaluated 36 prostate cancer patients with local recurrence after radiotherapy who received single or repeated cycles of replication-deficient adenoviral vector (ADV)-mediated herpes simplex virus-thymidine kinase (HSV-tk) plus ganciclovir (GCV) in situ gene therapy with respect to serum PSA levels, alterations in immune cells, and numbers of apoptotic cells in needle biopsies. An initial cycle of HSV-tk plus GCV gene therapy caused a significant prolongation of the mean serum PSA-doubling time (PSADT) from 15.9 to 42.5 months (p = 0.0271) and in 28 of the injected patients (77.8%) there was a mean PSA reduction (PSAR) of 28%. It took a mean of 8.5 months for the PSA to return to the initial PSA (TR-PSA) value. A repeated cycle of gene therapy failed to significantly extend PSADT but did result in significant increases in PSAR (29.4%) and TR-PSA (10.5 months). Moderately increased serum adenovirus antibody titers were generally observed 2 weeks after initial vector injection. Also at this time there was a statistically significant increase in the mean percent of CD8(+) T cells positive for the HLA-DR marker of activation in peripheral blood (p = 0.0088). Studies using prostate biopsies obtained at the same time point demonstrated that vector DNA was detectable by PCR in most samples yet all patients remained positive for prostate cancer in at least one biopsy core. Further analysis demonstrated a correlation between the level of CD8(+) cells and the number of apoptotic cells in biopsies containing cancer cells (p = 0.042). We conclude that repeated cycles of in situ HSV-tk plus GCV gene therapy can be administered to prostate cancer patients who failed radiotherapy and have a localized recurrence. Biological responses to this experimental therapy including increases in PSADT, PSAR, and TR-PSA, and activated CD8(+) T cells present in the peripheral blood, were demonstrated. Interestingly, the density of CD8(+) cells in posttreatment biopsies correlated with the number of apoptotic cells.

Disruption of the Caveolin-1 Gene Impairs Renal Calcium Reabsorption and Leads to Hypercalciuria and Urolithiasis

Using LoxP/Cre technology, we generated a knockout mouse homozygous for a null mutation in exon 2 of Cav1. In male Cav1-/- animals, we observed a dramatic increase in the incidence of urinary calcium stone formation. In 5-month-old male mice, the incidence of early urinary calculi was 67% in Cav1-/- mice compared to 19% in Cav1+/+ animals. Frank stone formation was observed in 13% of Cav1-/- males but was not seen in Cav1+/+ mice. Urine calcium concentration was significantly higher in Cav1-/- male mice compared to Cav1+/+ mice. In Cav1-/- mice, distal convoluted tubule cells were completely devoid of Cav1 and the localization of plasma membrane calcium ATPase was disrupted. Functional studies confirmed that active calcium absorption was significantly reduced in Cav1-/- compared to Cav1+/+ male mice. These results demonstrate that disruption of the Cav1 gene promotes the progressive steps required for urinary calcium stone formation and establish a new mouse model for urinary stone disease.

The Role Of Caveolin-1 In Androgen Insensitive Prostate Cancer

PURPOSE We summarize the literature regarding androgen insensitive prostate cancer and caveolin-1. Caveolin-1 is a major structural component of caveolae, membrane micro-domains known to have important roles in signal transduction and lipid transport. MATERIALS AND METHODS A review of the literature relevant to androgen insensitive caveolin-1 and prostate cancer included the first published report in 1998 through those published in March 2002. RESULTS Caveolin-1 expression is increased in primary and metastatic human prostate cancer with highest levels observed after androgen ablation therapy. Recent studies have documented that caveolin-1 is secreted by prostate cancer cells and can be detected in the serum of men with prostate cancer. CONCLUSIONS The results presented in this review establish that caveolin-1 is an autocrine/paracrine factor associated with androgen insensitive prostate cancer. They show the potential for caveolin-1 as a biomarker therapeutic target for this important malignancy.

Improved predictability of extracapsular extension and seminal vesicle involvement based on clinical and biopsy findings in prostate cancer in Japanese men

OBJECTIVES The accurate preoperative prediction of the extent of cancer by pathologic examination is essential for choosing the optimal treatment for patients with prostate cancer. Currently available clinical staging methods are not adequate and more precise staging is required. METHODS Using the log likelihood ratio test and receiver operating characteristic (ROC) curve analysis, preoperative variables, including biopsy pathologic findings, were assessed for predicting final pathologic stage in prostate cancer. A multivariate model for predicting disease organ confinement status was established for easy clinical use. RESULTS The use of the number of cores with cancer and maximum cancer length in conjunction with the three variables (prostate-specific antigen, clinical stage, and biopsy Gleason score) was found to significantly improve predictability of extracapsular extension and seminal vesicle involvement in clinically resectable (n = 96) and localized prostate cancers (n = 81) (P < 0.05). Areas under ROC curves for the above two parameter sets (five- versus three-variable model) were 0.8395 and 0.7109, respectively, for capacity for extracapsular extension prediction in clinically localized cancer. These values for seminal vesicle involvement were 0.7861 and 0.6927, respectively. The logistic model gave positive and negative predictive values of 73% and 78%, and 64% and 83%, respectively, for extracapsular extension and seminal vesicle involvement in clinically localized cancer at a predicted probability of 0.5 or greater. CONCLUSIONS The present method may be used to predict non-organ-confined prostate cancer with greater accuracy than the previously reported model using three variables.

Clinical significance of p53, mdm2, and bcl-2 proteins in renal cell carcinoma.

OBJECTIVES To improve our understanding of the clinical relevance of p53, mdm2, and bcl-2 protein overexpression in renal cell carcinoma, we retrospectively investigated the immunohistochemical expression of p53, murine double minute 2 (mdm2), and bcl-2 and the relationship of this expression to clinicopathologic characteristics. p53 regulates the transcription of downstream effectors such as the oncoprotein mdm2, and bcl-2 has been shown to inhibit apoptosis triggered by wild-type p53. METHODS The expression of p53, mdm2, and bcl-2 protein was studied by immunohistochemical methods in paraffin-embedded nephrectomy specimens from 112 patients whose clinicopathologic data confirmed renal cell carcinoma. RESULTS The expression of the p53 and bcl-2 protein was recognized in 15 (13.4%) and 52 (42.0%) cases, respectively; the expression of the mdm2 protein, however, was seen in only 2 cases (1.8%). No correlation was noted between these three proteins and any clinicopathologic parameters, except p53 expression and Stage T1-2/T3-4 (P = 0.0208). However, in multivariate analysis, stage (hazard ratio 3.586; P = 0.0002), expression of p53 (hazard ratio 6.090; P = 0.0126) and of mdm2 (hazard ratio 22.016; P = 0.0156), and coexpression of p53/mdm2 (hazard ratio 6.146; P = 0.0005) demonstrated a statistically significant effect on prognosis by proportional hazards regression tests. CONCLUSIONS Our results indicate that stage, p53 expression, mdm2 expression, and coexpression of p53/mdm2 are useful to predict the clinical outcome in patients with renal cell carcinoma.

Adenoviral Vector-Mediated mRTVP-1 Gene Therapy for Prostate Cancer

We previously identified the mouse RTVP-1 (mRTVP-1; related to testes-specific, vespid, and pathogenesis proteins) gene as a direct target of p53 with proapoptotic activities in various cancer cell lines, including prostate cancer. To test the therapeutic potential of mRTVP-1 we constructed an adenoviral vector capable of efficient transduction and expression of mRTVP-1 (AdmRTVP-1) and used this vector in an orthotopic, metastatic mouse model of prostate cancer. A single intratumoral administration of AdmRTVP-1 gene therapy significantly reduced primary tumor wet weight compared with control Adbetagal-injected tumors at two time points after injection with two different vector doses (p < or = 0.01 at 7 and 14 days). Spontaneous metastasis to lung was also significantly reduced (p < or = 0.02). Evaluation of treated tumors revealed increased apoptosis and lower microvessel density counts. In a rat aortic ring sprouting assay, AdmRTVP-1 inhibited endothelial cell sprouting compared with Adbetagal, confirming its antiangiogenic activity. These therapeutic activities were associated with a significant increase in survival from 22.9 to 26.8 days (p = 0.003) in this aggressive model of prostate cancer. Interestingly, there were significant increases in the infiltration of tumor-associated macrophages, dendritic cells, and CD8+ T cells, which persisted at 14 days posttreatment in the AdmRTVP-1-treated tumors compared with Adbetagal control-treated tumors. In addition, significantly increased natural killer and cytotoxic T lymphocyte activities were demonstrated in the mice with AdmRTVP-1-treated tumors. The unique therapeutic properties of AdmRTVP-1 gene therapy demonstrated in this study provide new opportunities for gene and immunotherapy of prostate cancer and potentially other malignancies.

Prevalence of Fluoroquinolone-resistant Escherichia coli Before and Incidence of Acute Bacterial Prostatitis After Prostate Biopsy

OBJECTIVE To study the prevalence of fluoroquinolone-resistant Escherichia coli before transrectal ultrasound (TRUS)-guided prostate biopsy and prospectively analyze the rates of infective complications after biopsy in patients receiving fluoroquinolone prophylaxis. E. coli is the pathogen most commonly associated with infections after TRUS-guided prostate biopsy, and the prevalence of fluoroquinolone-resistant E. coli is increasing. METHODS We analyzed the prospective data from 100 patients who underwent TRUS-guided prostate biopsy from April to December 2010. A stool culture was obtained 1 month before biopsy. Patients received 500 mg levofloxacin orally once daily for 3 days, beginning 2 hours before biopsy. All biopsies were performed as outpatient procedures. RESULTS Of the 100 patients, 13 (13%) had a stool culture positive for fluoroquinolone-resistant E. coli. In 4 (31%) of these 13 patients, acute bacterial prostatitis was detected after TRUS-guided prostate biopsy. Of the 87 patients whose stool culture was negative for fluoroquinolone-resistant E. coli, none had acute bacterial prostatitis. All 13 infected patients were treated with carbapenems immediately after diagnosis of prostatitis and made a complete recovery. CONCLUSION Prophylactic fluoroquinolone is still effective in preventing acute bacterial prostatitis after TRUS-guided prostate biopsy. The incidence is relatively low in patients with fluoroquinolone-sensitive E. coli. However, the prevalence of fluoroquinolone-resistant E. coli is about 13% in this population. Stool cultures for the detection of fluoroquinolone-resistant E. coli might be obtained before TRUS-guided prostate biopsy.