Is there an anti-androgen withdrawal syndrome for enzalutamide?

BACKGROUND: The anti-androgen withdrawal syndrome (AAWS) can be seen in one-third of patients after discontinuation of first-generation non-steroidal anti-androgen therapy. With the introduction of new agents for anti-androgen therapy as well as alternate mechanisms of action, new therapeutic options before and after docetaxel chemotherapy have arisen (Ohlmann et al. in World J Urol 30(4):495-503, 2012). The question regarding the occurrence of an enzalutamide withdrawal syndrome (EWS) has not been evaluated yet. In this study, we assess prostate-specific antigen (PSA) response after discontinuation of enzalutamide. METHODS: In total 31 patients with metastatic castration-resistant prostate cancer (mCRPC) underwent an enzalutamide withdrawal and were evaluated. Data were gathered from 6 centres in Germany. Patients with continuous oral administration of enzalutamide with rising serum PSA levels were evaluated, starting from enzalutamide withdrawal until subsequent therapy was initiated, follow-up ended or death of the patient occurred. Statistical evaluation was performed applying one-sided binomial testing using R-statistical software, version 3.0.1. RESULTS: Mean withdrawal follow-up was 6.5 weeks (range 1-26.1 weeks). None of the 31 patients showed a PSA decline. Mean relative PSA rise over all patients was 73.9 % (range 0.5-440.7 %) with a median of 44.9 %. CONCLUSIONS: If existent, an AAWS is at least very rare for enzalutamide in patients with mCRPC after taxane-based chemotherapy and does not play a clinical role in this setting. This may be attributed to the different pharmacodynamics of enzalutamide. Longer duration of therapy or a longer withdrawal interval may reveal a rare EWS in the future.

An IgG-based bispecific antibody for improved dual targeting in PSMA-positive cancer.

The prostate-specific membrane antigen (PSMA) has been demonstrated in numerous studies to be expressed specifically on prostate carcinoma cells and on the neovasculature of several other cancer entities. However, the simultaneous expression of PSMA on both, tumor cells as well as tumor vessels remains unclear, even if such "dual" expression would constitute an important asset to facilitate sufficient influx of effector cells to a given tumor site. We report here on the generation of a PSMA antibody, termed 10B3, which exerts superior dual reactivity on sections of prostate carcinoma and squamous cell carcinoma of the lung. 10B3 was used for the construction of T-cell recruiting bispecific PSMAxCD3 antibodies in Fab- and IgG-based formats, designated Fabsc and IgGsc, respectively. In vitro, both molecules exhibited comparable activity. In contrast, only the larger IgGsc molecule induced complete and durable elimination of established tumors in humanized mice due to favorable pharmacokinetic properties. Upon treatment of three patients with metastasized prostate carcinoma with the IgGsc reagent, marked activation of T cells and rapid reduction of elevated PSA levels were observed.

A Subpopulation of Stromal Cells Controls Cancer Cell Homing to the Bone Marrow.

Breast and prostate cancer cells home to the bone marrow, where they presumably hijack the hematopoietic stem cell niche. We characterize here the elusive premetastatic niche by examining the role of mesenchymal stromal cells (MSC) in cancer cell homing. Decreasing the number of MSC pharmacologically enhanced cancer cell homing to the bone marrow in mice. In contrast, increasing the number of these MSCs by various interventions including G-CSF administration diminished cancer cell homing. The MSC subpopulation that correlated best with cancer cells expressed stem, endothelial, and pericytic cell markers, suggesting these cells represent an undifferentiated component of the niche with vascular commitment. In humans, a MSC subpopulation carrying markers for endothelial and pericytic cells was lower in the presence of cytokeratin+ cells in bone marrow. Taken together, our data show that a subpopulation of MSC with both endothelial and pericytic cell surface markers suppresses the homing of cancer cells to the bone marrow. Similar to the presence of cytokeratin+ cells in the bone marrow, this MSC subpopulation could prove useful in determining the risk of metastatic disease, and its manipulation might offer a new possibility for diminishing bone metastasis formation.Significance: These findings establish an inverse relationship between a subpopulation of mesenchymal stromal cells and cancer cells in the bone marrow. Cancer Res; 78(1); 129-42. ©2017 AACR.

Microhematuria assessment an IBCN consensus-Based upon a critical review of current guidelines.

RATIONALE: Assessment of patients with asymptomatic microhematuria (aMh) has been a challenge to urologists for decades. The aMh is a condition with a high prevalence in the general population and also an established diagnostic indicator of bladder cancer. Acknowledging aMh needs to be assessed within a complex context, multiple guidelines have been developed to identify individuals at high risk of being diagnosed with bladder cancer. MATERIAL & METHODS: This structured review and consensus of the International Bladder Cancer Network (IBCN) identified and examined 9 major guidelines. These recommendations are partly based on findings from a long-term study on the effects of home dipstick testing, but also on the assumption that early detection of malignancy might be beneficial. RESULTS: Despite similar designs, these guidelines differ in a variety of parameters including definition of aMh, rating of risks, use of imaging modalities, and the role of urine cytology. In addition, recommendations for further follow-up after negative initial assessment are controversial. In this review, different aspects for aMh assessment are analyzed based upon the evidence currently available. DISCUSSION: We question whether adherence to the complicated algorithms as recommended by most guidelines is practical for routine use. Based upon a consensus, the authors postulate a need for better tools. New concepts for risk assessment permitting improved risk stratification and prepone cystoscopy before refined imaging procedures (computed tomography scan and magnetic resonance imaging) are suggested.

Considerations on the use of urine markers in the management of patients with high-grade non-muscle-invasive bladder cancer.

OBJECTIVE: Diagnosis and surveillance of high risk non muscle-invasive bladder cancer (NMIBC) represent specific challenges to urologists. In contrast to low/intermediate risk tumors, these tumors recur more frequently. A significant number will eventually progress to muscle-invasive bladder cancer, a life threatening disease requiring extensive therapeutic efforts. Although clinical risk factors have been identified that may predict tumor recurrence and progression, additional biomarkers are desperately needed to improve tumor diagnosis and guide clinical management of these patients. In this article, the role of molecular urine markers in the management of high risk NMIBC is analyzed. METHODS: In this context, several potential indications (diagnostic, prognostic, predictive) were identified and the requirements for molecular markers were defined. In addition, current knowledge within the different indications was summarized. RESULTS: Significant progress has been made in the last decade studying the impact of molecular urine markers in patients with high risk NMIBC. CONCLUSIONS: Although we may not be ready for the inclusion of molecular markers in clinical decision-making, and many questions remain unanswered, recent studies have identified situations in which the use of molecular markers in particular in high grade tumors may prove beneficial for patient diagnosis and surveillance.

Bladder cancer discussed on the internet: a systematic analysis of gender differences of initial posters on an online discussion board.

OBJECTIVES: To evaluate gender differences of initial posters in threads dealing with bladder cancer on an online discussion board. METHOD: 529 threads opened between 09/2005 and 03/2012 were screened on the largest German speaking bladder cancer online discussion board. 366 threads fulfilled the requirements for this study. Gender, age, number, status of concern and oncological situation of initiating posters as well as their motives and language style were analyzed following a standardized protocol. RESULTS: Threads were initiated in 45% (164/366) by men and in 55% (202/366) by women. Mean age of male initiating posters was 50 years and of female posters 44 years (p < 0.001). Of males 80% (132/164) were concerned patients and 20% (32/164) relatives or friends. Of females they were 39% (78/202) and 61% (124/202), respectively (p < 0.001). In general motives for initial posting were focused on medical information and did not differ between both genders. 81% of the posters asked for medical information or therapeutic recommendations regarding diagnosis, treatment and prognosis. However, women significantly more often expressed their wish for emotional support (p = 0.034) and in tendency wanted to share their experiences with others (p = 0.057). Language analysis revealed that women significantly more often used a tentative language style than men (p = 0.003). CONCLUSION: Even though women are less often affected by bladder cancer, they are more active -especially for their concerned family members - on the evaluated discussion board than men. Whereas both genders equally often ask for medical information, women more often want to share their experiences and look for emotional support.