Prostate cancer mortality predictions for Ireland up to 2015

Forced LIGHT expression in prostate tumors overcomes Treg mediated immunosuppression and synergizes with a prostate tumor therapeutic vaccine by recruiting effector T lymphocytes

BACKGROUND

LIGHT, a ligand for lymphotoxin-β receptor (LTβR) and herpes virus entry mediator, is predominantly expressed on activated immune cells and LTβR signaling leads to the recruitment of lymphocytes. The interaction between LIGHT and LTβR has been previously shown to activate immune cells and result in tumor regression in a virally-induced tumor model, but the role of LIGHT in tumor immunosuppression or in a prostate cancer setting, where self antigens exist, has not been explored. We hypothesized that forced expression of LIGHT in prostate tumors would shift the pattern of immune cell infiltration toward an anti-tumoral milieu, would inhibit T regulatory cells (Tregs) and would induce prostate cancer tumor associated antigen (TAA) specific T cells that would eradicate tumors.

METHODS

Real Time PCR was used to evaluate expression of forced LIGHT and other immunoregulatory genes in prostate tumors samples. For in vivo studies, adenovirus encoding murine LIGHT was injected intratumorally into TRAMP-C2 prostate cancer cell tumor bearing mice. Chemokine and cytokine concentrations were determined by multiplex ELISA. Flow cytometry was used to phenotype tumor infiltrating lymphocytes and expression of LIGHT on the tumor cell surface. Tumor-specific lymphocytes were quantified via ELISpot assay. Treg induction and Treg suppression assays determined Treg functionality after LIGHT treatment.

RESULTS

LIGHT in combination with a therapeutic vaccine, PSCA TriVax, reduced tumor burden. LIGHT expression peaked within 48 hr of infection, recruited effector T cells that recognized mouse prostate stem cell antigen (PSCA) into the tumor microenvironment, and inhibited infiltration of Tregs. Tregs isolated from tumor draining lymph nodes had impaired suppressive capability after LIGHT treatment.

CONCLUSION

Forced LIGHT treatment combined with PSCA TriVax therapeutic vaccination delays prostate cancer progression in mice by recruiting effector T lymphocytes to the tumor and inhibiting Treg mediated immunosuppression. Prostate 75:280-291, 2015. © 2014 Wiley Periodicals, Inc.

Challenges in generating costs and utilisation rates associated with castration-resistant prostate cancer

BACKGROUND

Prostate cancer (PCa), the most commonly diagnosed cancer among men in the United States and Europe, is an escalating resource allocation issue across healthcare systems in the Western world. The impact of skeletal-related events, associated with castration-resistant prostate cancer (CRPC), is considerable with many new therapies being sought to treat these events in a cost-effective manner.

AIMS

The aim of this paper is to provide insight into the level of constraints associated with devising cost frameworks for economic analysis of CRPC in the Irish healthcare setting.

METHODS

An informal questionnaire was devised to obtain estimates of utilisation to populate a decision tree model; existing parameters from the literature were also employed. Cost parameters included Irish reference costs, and a costs literature review was undertaken; a healthcare payer perspective was adopted. Pharmacy dosages used for modelling costs were calculated for an average 75 kg male.

RESULTS

The estimated average cost of care associated with adverse events in CRPC was €23,264. Approximately 40% of the costs of CRPC are attributed to skeletal-related events; therefore, reducing the number of skeletal-related events could significantly reduce the cost of care. In attempting to generate accurate and reliable cost parameters, this study highlights the challenges of conducting economic analysis in the Irish healthcare setting.

CONCLUSION

This study presents leading treatments and associated costs for CRPC patients in the Republic of Ireland (RoI), which are expected to steadily increase with demographic shifts. Further research is warranted in this area due to the limitations encountered in the study.

Novel predictive tools for Irish radical prostatectomy pathological outcomes: development and validation

AIMS

We developed and validated prostate cancer predictive models for Irish patients, allowing individualised predictions of radical prostatectomy pathological outcomes.

METHODS

Retrospective review of the Irish Prostate Cancer Research Consortium database from 2003 to 2008 was performed. Two predictive models were formulated: a replica of the Partin tables (n = 169) and a look-up table based on PSA and biopsy Gleason Score (n = 253). Clinico-pathological parameters were compared to the Partin data set. Internal validation was performed.

RESULTS

In total, 70% of patients were at clinical stage T1c. 5.8% had a PSA less than 4.1 ng/ml, whereas 25% of the Partin patients had a PSA in this range. Maximal predictive accuracy was seen for seminal vesicle invasion (area under the curve = 72%). Prediction of extra-prostatic extension and lymph node involvement was only equivalent to that of a chance phenomenon.

CONCLUSIONS

Our current results do not support the introduction of the formulated predictive models into routine clinical practice.