Clinically localised prostate cancer

Theranostic Nanoseeds for Efficacious Internal Radiation Therapy of Unresectable Solid Tumors

Malignant tumors are considered “unresectable” if they are adhere to vital structures or the surgery would cause irreversible damages to the patients. Though a variety of cytotoxic drugs and radiation therapies are currently available in clinical practice to treat such tumor masses, these therapeutic modalities are always associated with substantial side effects. Here, we report an injectable nanoparticle-based internal radiation source that potentially offers more efficacious treatment of unresectable solid tumors without significant adverse side effects. Using a highly efficient incorporation procedure, palladium-103, a brachytherapy radioisotope in clinical practice, was coated to monodispersed hollow gold nanoparticles with a diameter about 120 nm, to form ¹⁰³Pd@Au nanoseeds. The therapeutic efficacy of ¹⁰³Pd@Au nanoseeds were assessed when intratumorally injected into a prostate cancer xenograft model. Five weeks after a single-dose treatment, a significant tumor burden reduction (>80%) was observed without noticeable side effects on the liver, spleen and other organs. Impressively, >95% nanoseeds were retained inside the tumors as monitored by Single Photon Emission Computed Tomography (SPECT) with the gamma emissions of ¹⁰³Pd. These findings show that this nanoseed-based brachytherapy has the potential to provide a theranostic solution to unresectable solid tumors.

Surrogate end points: how well do they represent patient-relevant end points?

This review takes a critical look at the concept of replacing patient-relevant end points, such as morbidity or mortality, with surrogate end points in clinical trials. Surrogate end points can be measured earlier in the course of a clinical trial and so are thought to accelerate the drug development process. Furthermore, they might be beneficial to the patients themselves by allowing faster adjustment of therapeutic strategies. However, the fact that in the past several promising surrogate end points have not fulfilled their expectations emphasizes the importance of applying strict evaluation criteria. The evaluation of the candidate surrogate end point prostate-specific antigen using the Prentice criteria and a meta-analytic approach is discussed. Prostate-specific antigen is often used to replace overall or progression-free survival in prostate cancer trials testing the benefit of medical interventions.

Functionalized radioactive gold nanoparticles in tumor therapy

The development of new treatment modalities that offer clinicians the ability to reduce sizes of tumor prior to surgical resection or to achieve complete ablation without surgery would be a significant medical breakthrough in the overall care and treatment of prostate cancer patients. The goal of our investigation is aimed at validating the hypothesis that Gum Arabic-functionalized radioactive gold nanoparticles (GA-(198) AuNP) have high affinity toward tumor vasculature. We hypothesized further that intratumoral delivery of the GA-(198) AuNP agent within prostate tumor will allow optimal therapeutic payload that will significantly or completely ablate tumor without side effects, in patients with hormone refractory prostate cancer. In order to evaluate the therapeutic efficacy of this new nanoceutical, GA-(198) AuNP was produced by stabilization of radioactive gold nanoparticles ((198) Au) with the FDA-approved glycoprotein, GA. This review will describe basic and clinical translation studies toward realization of the therapeutic potential and myriad of clinical applications of GA-(198) AuNP agent in treating prostate and various solid tumors in human cancer patients.

FGF-8b induces growth and rich vascularization in an orthotopic PC-3 model of prostate cancer

Fibroblast growth factor 8 (FGF-8) is expressed at an increased level in a high proportion of prostate cancers and it is associated with a poor prognosis of the disease. Our aim was to study the effects of FGF-8b on proliferation of PC-3 prostate cancer cells and growth of PC-3 tumors, and to identify FGF-8b-associated molecular targets. Expression of ectopic FGF-8b in PC-3 cells caused a 1.5-fold increase in cell proliferation in vitro and a four- to fivefold increase in the size of subcutaneous and orthotopic prostate tumors in nude mice. Tumors expressing FGF-8b showed a characteristic morphology with a very rich network of capillaries. This was associated with increased spread of the cancer cells to the lungs as measured by RT-qPCR of FGF-8b mRNA. Microarray analyses revealed significantly altered, up- and downregulated, genes in PC-3 cell cultures (169 genes) and in orthotopic PC-3 tumors (61 genes). IPA network analysis of the upregulated genes showed the strongest association with development, cell proliferation (CRIP1, SHC1), angiogenesis (CCL2, DDAH2), bone metastasis (SPP1), cell-to-cell signaling and energy production, and the downregulated genes associated with differentiation (DKK-1, VDR) and cell death (CYCS). The changes in gene expression were confirmed by RT-qPCR. In conclusion, our results demonstrate that FGF-8b increases the growth and angiogenesis of orthotopic prostate tumors. The associated gene expression signature suggests potential mediators for FGF-8b actions on prostate cancer progression and metastasis.

The psychological aftermath of prostate cancer treatment choices: a comparison of depression, anxiety and quality of life outcomes over the 12 months following diagnosis

OBJECTIVE

To assess the psychological impact of the different treatments for localised prostate cancer (PCA).

DESIGN, PARTICIPANTS AND SETTING

Observational, prospective study of consecutive patients with PCA attending clinics in public hospitals and private practices in metropolitan Melbourne between 1 April 2001 and 30 December 2005. Data were collected at initial diagnosis of histologically confirmed localised PCA, and close to the commencement of definitive treatment (Time 1), and 12 months later (Time 2). Patients were stratified according to treatment type (radical prostatectomy [RP], hormone therapy [HT] or other early treatment including radiation therapies [OET]). Patients who elected to undergo active surveillance/watchful waiting (WW) rather than active treatment were treated as a naturalistic control group.

MAIN OUTCOME MEASURES

Levels of depression and anxiety were assessed by the Brief Symptom Inventory, and physical and psychosocial aspects of health-related quality of life (HRQOL) were assessed by the 36-item Short-Form Health Survey.

RESULTS

211 patients with PCA were recruited; 193 completed the Time 1 questionnaires (38 RP, 56 HT, 38 OET and 61 WW); and 172 completed the Time 2 questionnaires (33 RP, 51 HT, 33 OET and 55 WW). At Time 1, the three active treatment groups all reported greater dysfunction in work role and daily activities compared with the WW group. The RP group also reported worse social and emotional role functioning, while the HT and OET groups reported poorer vitality levels. The HT group reported significantly higher depression scores. At Time 2, the RP and OET groups did not differ from the WW group on either HRQOL or psychological status. By contrast, the HT group reported significantly worse HRQOL (physical functioning, role-physical and vitality domains) and greater psychological distress compared with the WW group.

CONCLUSIONS

Compared with the other active treatments for localised PCA, HT appears to be associated with poorer HRQOL and greater psychological distress 12 months after commencing treatment.

Harmonic motion detection in a vibrating scattering medium

Elasticity imaging is an emerging medical imaging modality that seeks to map the spatial distribution of tissue stiffness. Ultrasound radiation force excitation and motion tracking using pulse-echo ultrasound have been used in numerous methods. Dynamic radiation force is used in vibrometry to cause an object or tissue to vibrate, and the vibration amplitude and phase can be measured with exceptional accuracy. This paper presents a model that simulates harmonic motion detection in a vibrating scattering medium incorporating 3-D beam shapes for radiation force excitation and motion tracking. A parameterized analysis using this model provides a platform to optimize motion detection for vibrometry applications in tissue. An experimental method that produces a multifrequency radiation force is also presented. Experimental harmonic motion detection of simultaneous multifrequency vibration is demonstrated using a single transducer. This method can accurately detect motion with displacement amplitude as low as 100 to 200 nm in bovine muscle. Vibration phase can be measured within 10 degrees or less. The experimental results validate the conclusions observed from the model and show multifrequency vibration induction and measurements can be performed simultaneously.

The clinical management of patients with a small volume of prostatic cancer on biopsy: what are the risks of progression? A systematic review and meta-analysis

Clinically localized prostate cancer is associated with a wide variation in biologic behavior, and men with the less aggressive form of the disease may never develop symptoms. There has been a rise in prostate cancer incidence in countries in which the blood test for prostatic-specific antigen (PSA) is common, and concerns have been expressed that this may be because of the increased detection of indolent disease, subjecting these men to unnecessary treatment and associated side effects. For the current review, the authors conducted a systematic evaluation of the literature regarding the outcomes of men who were diagnosed on the basis of a small volume of cancer in prostatic biopsies. The results indicated that, despite differences in study design and reporting, a significant proportion of patients with microfocal cancer, regardless of how it was defined, had adverse pathologic findings and a significant risk of PSA recurrence after undergoing radical prostatectomy. Biochemical and clinical recurrences also were observed after radiotherapy or watchful waiting. The authors concluded that patients with microfocal carcinoma on biopsy should be advised that their disease is not necessarily "insignificant" and should be counseled accordingly.