Frank Perabo

Soy isoflavone genistein in prevention and treatment of prostate cancer

Dietary habits and incidence of prostate cancer (PCa) are very different in several parts of the world. Among the differences between Eastern and Western diets is the greater intake of soy in the Eastern cultures. This might be one factor contributing to a lower incidence of PCa in Asian men. Many studies using PCa cells and animal studies of chemical carcinogenesis have shown that a wide range of dietary compounds have cancer chemopreventive potential. Therefore, the interest in nutrition-based approaches for prevention and treatment of PCa is increasing. We reviewed all experimental preclinical in vitro and in vivo data as well as clinical trials performed with soy isoflavone genistein for prevention and treatment of PCa. The preclinical data for genistein presented in this review show a remarkable efficacy against PCa cells in vitro with molecular targets ranging from cell cycle regulation to induction of apoptosis. In addition, seemingly well-conducted animal experiments support the belief that genistein might have a clinical activity in human cancer therapy. However, it is difficult to make definite statements or conclusions on clinical efficacy of genistein because of the great variability and differences of the study designs, small patient numbers, short treatment duration and lack of a standardized drug formulation. Although some results from these genistein studies seem encouraging, reliable or long-term data on tumor recurrence, disease progression and survival are unknown. The presented data potentially allow recommending patients the use of genistein as in soy products in a preventive setting. However, at present there is no convincing clinical proof or evidence that genistein might be useful in PCa therapy.

Treatment of penile strangulation caused by constricting devices

Constricting devices placed on the penis present a challenge to urologists. Various nonmetallic and metallic objects are placed on the penis to increase sexual performance or because of autoerotic intentions. We describe five different cases of strangulating objects (wedding ring, metal plumbing cuff, bull ring, hammer- head, and plastic bottle neck) and demonstrate that each case needs individual handling in removing the object. The treatment of penile strangulation is decompression of the constricted penis to facilitate free blood flow and micturition. It requires no particular skill but does require resourcefulness to perform the removal simply and effectively, and with as little discomfort for the patient as possible.

Effect of enzalutamide on health-related quality of life, pain, and skeletal-related events in asymptomatic and minimally symptomatic, chemotherapy-naive patients with metastatic castration-resistant prostate cancer (PREVAIL): results from a randomised, phase 3 trial

BACKGROUND Enzalutamide significantly increased overall survival and radiographic progression-free survival compared with placebo in the PREVAIL trial of asymptomatic and minimally symptomatic, chemotherapy-naive patients with metastatic castration-resistant prostate cancer. We report the effect of enzalutamide on health-related quality of life (HRQoL), pain, and skeletal-related events observed during this trial. METHODS In this phase 3, double-blind trial, patients were randomly assigned (1:1) to receive enzalutamide 160 mg/day (n=872) or placebo (n=845) orally. HRQoL was assessed at baseline and during treatment using the Functional Assessment of Cancer Therapy-Prostate (FACT-P) and EQ-5D questionnaires. Pain status was assessed at screening, baseline, week 13, and week 25 with the Brief Pain Inventory Short Form (BPI-SF). The primary analysis of HRQoL data used a mixed-effects model to test the difference between least square means change from baseline at week 61. We assessed change from baseline, percentage improvement, and time to deterioration in HRQoL and pain, the proportion of patients with a skeletal-related event, and time to first skeletal-related event. Analysis was done on the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT01212991. FINDINGS Median treatment duration was 16·6 months (IQR 10·1-21·1) in the enzalutamide group and 4·6 months (2·8-9·7) in the placebo group. The mixed-effects model analyses showed significant treatment differences in change from baseline to week 61 with enzalutamide compared with placebo for most FACT-P endpoints and EQ-5D visual analogue scale. Median time to deterioration in FACT-P total score was 11·3 months (95% CI 11·1-13·9) in the enzalutamide group and 5·6 months (5·5-5·6) in the placebo groups (hazard ratio [HR] 0·62 [95% CI 0·54-0·72]; p<0·0001). A significantly greater proportion of patients in the enzalutamide group than in the placebo group reported clinically meaningful improvements in FACT-P total score (327 [40%] of 826 vs 181 [23%] of 790), in EQ-5D utility index (224 [28%] of 812 vs 99 [16%] of 623), and visual analogue scale (218 [27%] of 803 vs 106 of [18%] 603; all p<0·0001). Median time to progression in BPI-SF pain at its worst was 5·7 months (95% CI 5·6-5·7) in the enzalutamide group and 5·6 months (5·4-5·6) in the placebo group (HR 0·62 [95% CI 0·53-0·74]; p<0·0001). Progression of pain at its worst was less common in the enzalutamide group than in the placebo group at week 13 (220 [29%] of 769 vs 257 [42%] of 610; p<0·0001), but not at week 25 (225 [32%] of 705 vs 135 [38%] of 360; p=0·068). 278 (32%) of 872 patients in the enzalutamide group and 309 (37%) of 845 patients in the placebo group had experienced a skeletal-related event by data cutoff. Median time to first skeletal-related events in the enzalutamide group was 31·1 months (95% CI 29·5-not reached) and 31·3 months (95% CI 23·9-not reached) in the placebo group (HR 0·72 [95% CI 0·61-0·84]; p<0·0001). INTERPRETATION In addition to improving overall survival relative to placebo, enzalutamide significantly improves patient-related outcomes and delays occurrence of first skeletal-related event in chemotherapy-naive men with metastatic castration-resistant prostate cancer. FUNDING Astellas Pharma and Medivation.

Cell-Free Circulating DNA: Diagnostic Value in Patients With Testicular Germ Cell Cancer

PURPOSE Increased levels of cell-free circulating DNA have been described in various malignancies as a diagnostic and prognostic biomarker. We analyzed the significance of cell-free DNA in patients with testicular cancer. MATERIALS AND METHODS Cell-free DNA was isolated from the serum of 74 patients with testicular cancer, including 39 with seminoma and 35 with nonseminoma, and 35 healthy individuals. Real-time polymerase chain reaction was used to quantify a 106, a 193 and a 384 actin-beta DNA fragment. DNA integrity is expressed as the ratio of large (193 or 384 bp) to short (106 bp) DNA fragments. RESULTS Actin-beta-106/193/384 fragment levels were significantly increased in patients with cancer compared to those in healthy individuals (each p <0.001). DNA integrity was significantly decreased in patients with cancer (p <0.001). Cell-free DNA fragment levels were not different when comparing patients with nonseminoma and seminoma (p >0.24). ROC analysis demonstrated that cell-free DNA levels distinguished patients with cancer from healthy individuals with 87% sensitivity and 97% specificity. Even in 31 patients in whom the established serum tumor markers alpha-fetoprotein, human chorionic gonadotropin, placental alkaline phosphatase and lactate dehydrogenase were normal cell-free DNA levels allowed us to distinguish between patients with cancer and healthy individuals with 84% sensitivity and 97% specificity. Cell-free DNA levels were more frequently increased in patients with clinical stage 3 than in patients with stage 1 or 2 disease (p <0.046). CONCLUSIONS Cell-free DNA levels are increased in patients with testicular cancer and they allow the accurate discrimination of healthy individuals. The high sensitivity of cell-free DNA could facilitate the management of testicular cancer, especially in patients with conventional tumor markers that are not increased.

Enzalutamide monotherapy in hormone-naive prostate cancer: primary analysis of an open-label, single-arm, phase 2 study

BACKGROUND The androgen receptor inhibitor enzalutamide is approved for the treatment of metastatic castration-resistant prostate cancer that has progressed on docetaxel. Our aim was to assess the activity and safety of enzalutamide monotherapy in men with hormone-naive prostate cancer. METHODS This trial is an ongoing open-label, single-arm, phase 2 study, done across 12 European sites. Men aged over 18 years, with hormone-naive prostate cancer for whom hormone therapy was indicated, and who had non-castration levels of testosterone and prostate-specific antigen (PSA) of 2 ng/mL or greater at screening, and an Eastern Cooperative Oncology Group score of 0, received oral enzalutamide 160 mg/day. The primary outcome was the proportion of patients with an 80% or greater decline in PSA at week 25. All analyses included all patients who had received at least one dose of the study drug. This study is registered with ClinicalTrials.gov, number NCT01302041. FINDINGS 67 men were enrolled into the study. 62 patients (92.5%, 95% CI 86.2-98.8) had a decline in PSA of 80% or greater at week 25. The most commonly reported treatment-emergent adverse events up to week 25 were gynaecomastia (n=24), fatigue (n=23), nipple pain (n=13), and hot flush (n=12), all of which were of mild to moderate severity. Nine patients had a treatment-emergent adverse event of grade 3 or higher, most of which were reported in one patient each, except for pneumonia (grade 3, two patients) and hypertension (grade 3, four patients). Five patients reported serious adverse events, none of which were deemed to be treatment related. INTERPRETATION Our findings suggest that enzalutamide monotherapy in men with hormone-naive prostate cancer of varying severity provides a level of disease suppression, and was generally well tolerated. These findings provide a rationale for further investigation of clinical response and outcomes with enzalutamide in non-castrate men with prostate cancer.

Apoptotic DNA fragments in serum of patients with muscle invasive bladder cancer: A prognostic entity

Patients with malignancies often possess increased concentrations of cell-free serum DNA. In this study, we investigated serum DNA levels in each 45 patients with bladder cancer (BCA) undergoing radical cystectomy and with benign prostate hyperplasia. A quantitative real-time PCR was used to amplify a 124 bp (PTGS2; mostly apoptotic origin) and a 271 bp (Reprimo; mostly necrotic origin) DNA fragment. Changes in the origin of DNA fragments were specified as the Apoptosis Index (AI, ratio of 124 bp/271 bp fragments). Small and large fragments were increased (p<0.001 and p=0.041) in BCA patients. The AI increase suggests that DNA fragmentation was mostly (p<0.001) caused by apoptosis. High levels of small DNA fragments distinguished between BCA and BPH with high sensitivity (96%) and moderate specificity (62%). DNA levels and the AI were not correlated with clinicopathological parameters. However, an increased AI was correlated with BCA-specific mortality in a multivariate analysis (p=0.011) indicating that the AI is an independent prognostic factor. Thus, cell-free DNA seems to be a useful prognostic marker in patients with BCA.

Preclinical evaluation of superantigen (staphylococcal enterotoxin B) in the intravesical immunotherapy of superficial bladder cancer.

Superantigens are potent activators of T lymphocytes; therefore, their characteristics can be exploited in diseases where immunomodulation is known to be effective. In this study, we evaluated a new approach for the intravesical therapy of superficial bladder cancer. We investigated in coculture experiments if staphylococcal enterotoxin B (SEB)–activated PBMCs are able to induce apoptosis in human transitional cell carcinoma (TCC) cells. Additionally, we tested the toxicity and efficacy of SEB dissolved in NaCl 0.9% administered intravesically once weekly for 6 weeks in a rat bladder cancer model. To validate the coculture in vitro findings, we evaluated tumor stage, grade, apoptotic cells in the urothelium and stroma of the bladder and infiltration of the bladder wall by lymphocytes, macrophages and mononuclear cells. Coculture experiments revealed that SEB‐activated PBMCs are able to kill TCC cells by inducing apoptosis. The intravesical toxicity study with a maximum dose of 100 μg/ml SEB demonstrated no side effects. In the intravesically SEB‐treated animals (10 μg/ml), only 3 tumors remained vs. 15 persisting tumors in the control group. The remaining tumors of the therapy group showed a significant amount of apoptosis and granulocytes, mainly in the urothelium, whereas no relevant apoptosis or infiltration of the bladder with lymphocytes or macrophages was found in the control group. These preclinical findings suggest that SEB might be an interesting candidate for further clinical evaluation.

Bladder cancer cells acquire competent mechanisms to escape Fas-mediated apoptosis and immune surveillance in the course of malignant transformation

Mechanisms of resistance against Fas-mediated cell killing have been reported in different malignancies. However, the biological response of immune escape mechanisms might depend on malignant transformation of cancer cells. In this study we investigated different mechanisms of immune escape in 2 well-differentiated low-grade (RT4 and RT112) and 2 poorly differentiated high-grade (T24 and TCCSUP) bladder cancer cell lines. Fas, the receptor of Fas-ligand, is expressed and shedded by human transitional bladder carcinoma cell lines RT4, RT112, T24 and TCCSUP. Cytotoxicity and apoptosis assays demonstrate that in spite of the Fas expression, poorly differentiated T24 and TCCSUP cells are insensitive towards either recombinant Fas-ligand or agonistic apoptosis-inducing monoclonal antibody against Fas. In poorly differentiated T24 and TCCSUP cell lines we were able to detect marked Fas-ligand protein by flow cytometry and Western blot analysis. In grade 1 RT4 and RT112 cells only minor expression of Fas-ligand possibly because of proteinase action. Fas-ligand mRNA translation or post-translational processing seems to be regulated differentially in the cancer cell lines depending on malignant transformation. In co-culture experiments we show that poorly differentiated cells can induce apoptosis and cell death in Jurkat cells and activated peripheral blood mononuclear cells. This in vitro study suggests that bladder cancer cells can take advantage of different mechanisms of immune evasion and become more competent in avoiding immune surveillance during transformation to higher-grade malignant disease.

Soluble Fas and Fas-ligand in bladder cancer in vitro and in vivo

Circulating soluble Fas (sFas) and expression of Fas-ligand on cancer cells are mechanisms of immune escape. The aim of the present study was to investigate expression and production of Fas and Fas-ligand on bladder cancer cell lines of different grade as a basic mechanism of their secretion in vivo. sFas and sFas-ligand serum levels of patients with different stage of bladder cancer were examined to determine the possible clinical use of these molecules as tumor markers. Bladder cancer cell lines RT4 (G1), RT112 (G1), T24 (G3) and SUP (G4) were analyzed by flowcytometry for Fas and Fas-ligand expression. To determine if the Fas-ligand gene is transcribed in these bladder cancer cell lines, RT-PCR was performed on mRNA extracted from these cell lines. Production of sFas and sFas-ligand was examined in cell culture supernatants of the cancer cells as well as in the serum of 62 patients with bladder cancer by a specific ELISA test. We demonstrate that Fas is expressed in similar levels on all human bladder carcinoma cell lines. In T24 (G3) and SUP (G4) cell lines we were able to detect the Fas-ligand protein, whereas no Fas-ligand protein could be found in RT4 and RT112 (G1) cells. Fas-ligand mRNA was expressed in all bladder cancer cell lines. Furthermore, all bladder cancer cell lines produce sFas but no sFas-ligand in spite of mRNA expression. The range of sFas levels in the serum of all patients with bladder cancer was large and did not show a correlation to the histopathological stage of bladder cancer. Although there is in vitro evidence that sFas and Fas-ligand play a role in bladder cancer, no correlation between the sFas and s Fas-ligand serum levels and the histopathological stage of bladder cancer could be found. Therefore, serum sFas and sFas-ligand have to date limited clinical relevance.

Squamous cell carcinoma of the penis.

Summary. Squamous cell carcinoma of the penis is a rare disease in Western countries. In geographical locations where infantile circumcision is not routinely practised and genital hygiene is poor, penile cancer may comprise 10–20% of all malignancies. Superficial tumours (Ta‐T1) should be treated with organ‐preserving therapy. Partial or total penectomy is recommended for invasive penile carcinoma (stage T2 or higher). Currently, management of the ilioinguinal lymph nodes is controversial. The value of radiation therapy and chemotherapy is still uncertain; these treatments are only palliative therapy modalities.