Prostate cancer: where are we and where are we going?

[Prostate cancer: medicoeconomic aspects]

Prostate cancer is the first cancer in men. Its incidence is constantly increasing. The significant evolution of diagnostic and therapeutic means during the two last decades contrasts with the scarcity of medicoeconomic studies. The aim of this review is to present a synthesis of the different studies published and to respond to questions about the economic aspects of this disease, with the evaluation of its direct and indirect costs. The cost-effectiveness and the benefits of the prevention and the screening are still being studied. The costs of the surgery and the radiotherapy are roughly similar. The new surgical techniques, especially the laparoscopic and the robotic surgeries, are not necessarily associated with higher costs, in condition of a high-volume laparoscopic surgery program and a faster discharge. The indirect costs of prostate cancer concern the loss of economic production associated with the disease and death and are more difficult to determine.

Screening and treatment for prostate cancer: The evidence and implications for practice

Prostate cancer is the second most diagnosed cancer in men, but there is considerable debate over whether or not to screen for the condition. The issues in the debate surrounding screening are clarified in this paper. One of the recommendations of the guidelines for urology from the National Institute for Clinical Excellence (NICE, 2002) is that patients receive balanced information about management options for their condition.

The NICE guidelines also suggest that ‘major improvements' are required in information and support services for patients and carers, and that nurse specialists in the urology cancer team will play a key role in these services. The options for management and treatment are discussed in the light of these recommendations and the relative merits of each are considered.

RRR-alpha-tocopheryl succinate inhibits human prostate cancer cell invasiveness

RRR-alpha-tocopheryl succinate (alpha-vitamin E succinate, VES), one of the vitamin E derivatives, can effectively inhibit the proliferation of human prostate cancer cells. However, little is known about its effect on prostate cancer cell invasive ability. Tumor metastasis is a complex process and the extracellular matrix (ECM) is the first barrier that tumor cells encounter. Therefore, we tested the effect of VES on the invasion of different prostate tumor cells, PC-3, DU-145, and LNCaP, through Matrigel, a reconstituted ECM, using an in vitro cell invasion assay. The invasion of PC-3 and DU-145 cells through Matrigel was inhibited by 20 microM VES after treating for 24 h. The condition did not alter cell survival, cell cycle, cell adhesion or cell motility. We further investigated whether the ability of VES to inhibit prostate cancer cell invasiveness was associated with its ability to inhibit the activity of matrix metalloproteinases (MMPs), the key enzymes in the proteolysis of basement membrane during invasion. PC-3 and DU-145 cells that were treated with VES showed a significant reduction in the levels of MMP-9 in the culture medium. In contrast, LNCaP cells, which did not secrete MMP-9, were poorly invasive in Matrigel and were hardly affected by treatment with VES. This is the first report suggesting that VES inhibits human prostate cancer cell invasiveness and the reduction of secreted MMP-9 activity could be one of the contributory factors, which points to the potential use of VES in the prevention and therapy of prostate cancer invasion.

Resveratrol: a candidate nutritional substance for prostate cancer prevention

The dietary stilbene resveratrol is a major constituent of a variety of edible plant products, including grapes and peanuts. Resveratrol has been identified as an excellent candidate cancer chemopreventive, based on its safety and efficacy in animal models of carcinogenesis. Resveratrol is a prototype of a plethora of bioactive polyphenols in the food supply that has just begun to be mined for cancer preventive agents. For example, polyphenolic grapeseed fractions were shown recently to potently antagonize chemical carcinogenesis. Taking into consideration that the identification of resveratrol as a cancer preventive agent is largely owed to its high abundance in nature (e.g., it accounts for 5-10% of the grapeskin biomass), it is logical to expect that naturally occurring stilbenes that are superior to resveratrol in their cancer preventive properties await identification. Thus, resveratrol may represent the tip of the iceberg of a broad class of stilbene and related polyphenolic natural products that include safe and highly effective agents for cancer prevention. We hypothesize that resveratrol may be especially suitable as a lead agent for prostate cancer prevention given its ability to: 1) inhibit each stage of multistage carcinogenesis, 2) scavenge incipient populations of androgen-dependent prostate cancer cells through androgen receptor antagonism, and 3) scavenge incipient populations of androgen-independent prostate cancer cells by short-circuiting the epidermal growth factor-receptor (EGFR)-dependent autocrine loops in the cancer cells.

A bridge between neuroscience and oncology: prostate cancer genesis. A 'negative' consequence of learning?

Prostate cancer has become the most commonly diagnosed cancer in men over recent years. The initiating mechanism for tumorigenesis within the prostate remains an unknown. The observation, that the cancer incidence in patients with chronic neurological disabilities is significantly lower than in the normal population lead to the hypothesis, that changed processing due to a barrage of aberrant sensory information within a healthy CNS can trigger events within the prostate cell, that cause malignant transformation. There is a broad overlap of cellular mechanism of gene expression, that lead to either long term potentiation, learning and memory storage or deregulated differentiation and malignant transformation.

The development of erectile dysfunction in men treated for prostate cancer

PURPOSE

Erectile dysfunction is a common side effect in men treated for prostate cancer. Previously published studies document the incidence of erectile dysfunction in men treated for prostate cancer to be between 20% and 88%. To our knowledge a prospective evaluation focused on the development of erectile dysfunction in men treated for prostate cancer has not elucidated components of its chronology or risk factors.

MATERIALS AND METHODS

A centralized prospective database of 2,956 patients diagnosed with prostate cancer at a single institution was studied in regard to pretreatment and posttreatment erectile dysfunction. Of these 2,956 patients 802 had sufficient information regarding erectile function and comprise our study population. Factors analyzed in regard to treatment and erectile dysfunction include treatment modality, that is radical prostatectomy, external beam radiation therapy and watchful waiting, and ethnicity, patient age, clinical stage and tumor histological grade.

RESULTS

No significant difference was noted in the posttreatment erectile function between patients treated with radical prostatectomy or external beam radiation (10% versus 15%). Patients selecting watchful waiting had the lowest risk of erectile dysfunction. Clinical stage and race were significant predictors for the development of erectile dysfunction in the watchful waiting and external beam radiation treatment groups.

CONCLUSIONS

Erectile dysfunction develops in greater than 80% of patients treated for prostate cancer. External beam radiation has the same risk for erectile dysfunction as radical prostatectomy.

Antitumor activity of the polyamine analog N(1), N(11)-diethylnorspermine against human prostate carcinoma cells

BACKGROUND

Recent studies indicate that N-terminally bis-ethylated-polyamine analogs have significant antitumor activity in several human solid-tumor models. In this study, the in vitro and in vivo antitumor potential of the polyamine analog N(1), N(11)-diethylnorspermine (DENSpm) in human prostate carcinoma cells was examined.

METHODS

The antiproliferative and biochemical effects of DENSpm were tested in four human prostate cancer cell lines, i.e., PC-3, TSU-pr1, DU-145, and JCA-1. The in vivo antitumor potential was explored in two groups of nude mice bearing small or more developed xenografts of the DU-145 cell line. The mice were treated with 40 mg/kg DENSpm, three times per day for two cycles of 6 days, on days 1-6 and 8-13.

RESULTS

In vitro studies showed that all four tested human prostate carcinoma cell lines were sensitive to DENSpm in micromolar concentrations. In tumor-bearing mice, DENSpm clearly prevented tumor growth in both size groups, which became significant after day 17. Treatment with DENSpm evoked intracellular accumulation of the analog and various regulatory responses, e.g., downregulation of the polyamine biosynthesis, the induction of the catabolic enzyme spermidine/spermine N(1)-acetyltransferase (SSAT), and the depletion or decrease of natural polyamines. The cellular sensitivity to growth inhibition by DENSpm only correlated with the degree of ODC inhibition and SSAT induction.

CONCLUSIONS

DENSpm has sustained inhibitory effects on the growth of human prostate carcinoma cells in vitro as well in vivo. This polyamine analog may provide a new tool in the chemotherapy of prostate cancers with various phenotypes.

Treatment of prostate cancer

Prostate cancer is the leading cause of cancer death among older men in western countries. However, controversy surrounds many issues related to this disease, particularly its most appropriate treatment, with a wide spectrum of opinions ranging from watchful waiting to aggressive therapy. Patients with newly diagnosed prostate cancer, as well as their doctors, will have to make difficult decisions regarding treatment of this disease. In this article we discuss the current available treatment options and some novel therapeutic approaches to tackling the patient with prostate cancer.