Critical review of complementary therapies for prostate cancer

Preparation of PCL Electrospun Fibers Loaded with Cisplatin and Their Potential Application for the Treatment of Prostate Cancer

Prostate cancer is a global fatal type of cancer. It is a type of cancer that affect men. Signs and symptoms of the disease include blood in the urine, pain when one micturates, and difficulties in penis erection. Cisplatin chemotherapy is a principal treatment normally given to the prostate cancer patients. Nonetheless, on its own, cisplatin loses efficacy once administered due to liver pass effects and other biochemical attacks. In this paper, we looked at preparation of PCL nanoparticles loaded with cisplatin and their potential for the treatment of prostate cancer. PCL nanoparticles protect cisplatin from biochemical attack, thus increasing drug efficacy. Incorporation of P-glycoprotein inhibitors in PCL nanoparticles (NPs) loaded with cisplatin could improve prostate cancer treatment even more.

Changes in Bronchoalveolar Lavage Cells after Intratracheal Instillation of Dimethyl Selenide in Mice

CD-1 mice were exposed to a single intratracheal instillation of either 0.025 or 0.075 mg Se/kg wt of dimethyl selenide (DMSe). They were studied over 4 weeks to define the cellular inflammatory response of the airways to DMSe. Bronchoalveolar (BAL) lavage was used to collect the DMSe-induced inflammatory exudates. The DMSe instillation resulted in phlogistic responses that had the neutrophil as the main leukocyte; they were present in BAL samples, mostly at days 1 and 7. Macrophages were also increased during DMSe-induced inflammation. The lower DMSe dose resulted in an inflammatory reaction lasting for 2 weeks. Mice treated with the higher DMSe dose still showed elevated numbers of neutrophils and macrophages 4 weeks after instillation. DMSe did not change the number of lymphocytes harvested from the airways. An early increase in total protein of BAL, and late enhancement in lactate dehydrogenase was observed in mice treated with the high DMSe dose. We conclude that inhalation of DMSe triggers a moderate and dose-dependent inflammatory reaction in the mouse airways, and that this phlogistic reaction is likely to participate in the damage of respiratory epithelia that occurs upon DMSe inhalation.

MD-miniRNA could be a more accurate biomarker for prostate cancer screening compared with serum prostate-specific antigen level

Prostate cancer and prostatic hyperplasia detection remains a great challenge, lacking of effective non-invasive and specific diagnostic biomarkers. In the current study, we aimed to identify the relative expression of plasma MD-miniRNA and its diagnostic performance in differentiating prostate cancer and prostatic hyperplasia patients from healthy controls, compared with serum prostate-specific antigen (PSA) level. All of the clinical participants (63 prostate cancer patients, 32 prostatic hyperplasia patients, and 50 healthy controls) were obtained from the Third Affiliated Hospital of Suzhou University in China between January 2013 and April 2014. Clinical characteristics were well matched. Plasma samples were extracted to test the relative expression of MD-miniRNA using the method of qRT-PCR. SPSS 22.0 statistical software package was used to analyze the data and GraphPad Prism 6.0 was used to generate the graphs. Relativity expression of plasma MD-miniRNA was significantly upregulated in prostate cancer, compared with prostatic hyperplasia patients and healthy controls. Serum PSA level revealed similar differences among these groups. MD-miniRNA presented a relatively high diagnostic accuracy with AUC of 0.86 (95 % CI 0.80-0.93) in differentiating prostate cancer patients from healthy controls. Simultaneously, MD-miniRNA was able to discriminate prostate cancer patients from prostatic hyperplasia controls with AUC of 0.79 (95 % CI 0.70-0.88). In addition, MD-miniRNA displayed a better diagnostic performance than PSA level. However, the panel of these two biomarkers revealed the best diagnostic performance, compared with either single biomarker. Results of this study showed that plasma MD-miniRNA could serve as a promising and noninvasive biomarker for diagnosing prostate cancer. Further large-scale studies are needed to confirm its clinical diagnosis accuracy.

How can I help myself? A critical review of modifiable behaviors, medications, and complementary alternative medicine for men receiving radiotherapy for prostate cancer

Men receiving radiation for prostate cancer frequently want to know what steps they can take to optimize their chance of cure and reduce their risk of side effects. A variety of modifiable behaviors, medications, and complementary alternative medicine interventions have been investigated in this regard. In this review, we summarize data on tobacco use, exercise, statins and aspirin, and vitamins. There is limited randomized data supporting any of the interventions and additional studies are needed before clinicians can confidently inform their patients regarding what steps to take to improve their outcomes.

A panel of five circulating microRNAs as potential biomarkers for prostate cancer

BACKGROUND

Circulating microRNA (miRNAs) have been shown to have the potential as noninvasive diagnosis markers in several types of cancers. In this study, we investigated whether circulating miRNAs could be used in the diagnosis of prostate cancer (CaP) in a Chinese patient population.

METHODS

Illumina's Human v2 miRNA microarray was used to analyze miRNAs levels in a small set of patients [25 CaP, 17 benign prostatic hyperplasia (BPH)] in an effort to identify CaP-specific miRNAs. The identified miRNAs were further examined by quantitative real-time PCR (qRT-PCR) in the same small set of patients. After the training phase of screening and selecting, the candidate miRNAs were validated in a larger independent cohort (80 CaP, 44 BPH, and 54 healthy controls) with qRT-PCR in the verification phase.

RESULTS

Five miRNAs were confirmed by qRT-PCR analysis in validation sets. Receiver operating characteristic (ROC) curve analysis showed all 5 miRNAs had diagnostic value. More importantly, further principal component analysis indicated component 1 extracted from expression data of the 5 miRNAs could differentiate CaP from BPH and healthy controls with high diagnosis performance, with an AUC of 0.924 and 0.860, respectively.

CONCLUSIONS

Our data suggested that circulating miRNAs could serve as biomarkers for CaP, and compared to single miRNA, the 5 miRNAs panel can accurately discriminate CaP from BPH and healthy controls with high sensitivity and specificity, and therefore, combined with routine PSA test, these 5 CaP-specific miRNAs may help improve CaP diagnosis in clinical application.

Lycopene for the prevention of prostate cancer

BACKGROUND

Prostate cancer is a common cause of death in developed countries, yet the benefits of screening for prostate cancer still remain controversial. A prostate-specific antigen (PSA) test result greater than 4 ng/mL (nanograms/millilitre) has commonly been used as the cut-off level for seeking further tests to diagnose the presence (or absence) of prostate cancer. An increase in PSA levels may not necessarily be associated with an increased risk of prostate cancer, as PSA levels may also be increased in men with benign prostatic hyperplasia and prostatitis. Despite the uncertainty of the net benefit of early detection and treatment, safe and effective methods to prevent prostate cancer are of value. Consumers, seeking greater involvement in their healthcare, are increasingly turning to lifestyle modification and complementary and alternative medicines (CAMs) to maintain their health and prevent disease. Lycopene is a member of the carotenoid family, which is found abundantly in tomatoes, tomato-based products, strawberries, and watermelon. It has been hypothesised that lycopene is a strong antioxidant, which may lower the risk of cancer (including prostate cancer) in people who have diets rich in lycopene.

OBJECTIVES

To determine whether lycopene reduces the incidence of prostate cancer and prostate cancer-specific mortality. Secondary objectives include changes in PSA levels, prostate symptoms and the nature of adverse events associated with lycopene use.

SEARCH METHODS

Electronic searches were conducted across MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) databases. No language or other limitations were imposed.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that investigated the use of lycopene for the prevention of prostate cancer were eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

A search of electronic databases, performed in August 2011, identified 64 citations. All articles were selected for full-text review. From these citations, three studies were identified as meeting the inclusion criteria. Handsearching did not provide any additional studies.

MAIN RESULTS

Three RCTs, with a total of 154 participants were included in this review. None of the studies reported data on prostate cancer mortality. All of the included studies differed with respect to design, participants included and allocation of lycopene. This clinical heterogeneity limits the value on the pooled estimated of the meta-analyses. The methodological quality of two of the three included studies was assessed as posing a 'high' risk of bias. Meta-analysis indicated no statistical difference in PSA levels between men randomised to receive lycopene and the comparison group (MD (mean difference) -0.34, 95% CI (confidence interval) -2.01, 1.32). Only one study reported incidence of prostate cancer (10% in the lycopene group versus 30% in control group). The level of lycopene was also not statistically different in men randomised to receive lycopene and the comparison group (MD 0.39 µg/mL (micrograms/millilitre), 95% CI -0.19, 0.98). No other meta-analyses were possible since other outcomes assessed only had one study contributing data.

AUTHORS' CONCLUSIONS

Given that only three RCTs were included in this systematic review, and the high risk of bias in two of the three studies, there is insufficient evidence to either support, or refute, the use of lycopene for the prevention of prostate cancer. Similarly, there is no robust evidence from RCTs to identify the impact of lycopene consumption upon the incidence of prostate cancer, prostate symptoms, PSA levels or adverse events.

Use of Chinese medicine among prostate cancer patients in Taiwan: a retrospective longitudinal cohort study

The National Health Insurance (NHI) covers Western medicine and Chinese medicine (CM) in Taiwan. The present study aimed to investigate the trends and characteristics of CM use among prostate cancer patients before and after diagnosis. A retrospective longitudinal cohort study was carried out using the NHI research database. The present study cohort consisted of 4720 prostate cancer patients diagnosed in 2004. Claims of CM services of these patients between 2003 and 2008 were analyzed. The prevalence of CM use of this cohort was 25.8%, 26.8%, 23.6%, 22.4%, 22.0% and 21.1% in 2003-2008, respectively. Overall, 52.6% of this cohort had ever used CM. In the first year of diagnosis, there was the greatest increase of new CM users (12.1%). The total number of CM users and visits reached the peak in 2004 and decreased in the subsequent years (2005-2008). The average number of CM visits per user was 6.7, 6.7, 7.0, 7.1, 7.3 and 7.2 in 2003-2008, respectively. The most frequently recorded principal diagnosis of CM visits was musculoskeletal diseases (21.4%), symptoms/signs (17.6%) and neoplasms (11.7%). Chinese herbal medicine (75.1%) was the most commonly used, followed by acupuncture/traumatological manipulative therapies (29.7%). Patients using CM before diagnosis tended to be CM users after diagnosis. The increase of CM use over the first year of prostate cancer diagnosis can be primarily attributed to an increase of new CM users, rather than of CM visits per users.

Trends in Chinese medicine use among prostate cancer patients under national health insurance in Taiwan: 1996-2008

BACKGROUND

Taiwan National Health Insurance (NHI) provides Western medicine and Chinese medicine (CM). This study aims to explore the trends of CM use among prostate cancer patients under NHI.

METHODS

Claims of CM outpatient services from 1996 to 2008 were obtained from NHI Research Database. CM visits of prostate cancer patients were identified. Claims with diagnosis code of prostate cancer were defined as cancer-specific visits.

RESULTS

Among 78 323 prostate cancer patients identified during 1996-2008, there were 30 383 (38.8%) CM users and 327 063 CM outpatient visits. The prevalence of CM use in each cross-sectional year increased slightly from 24.9% to 25.6%. Most CM visits (92.7%) were non-cancer-specific. There were greater increases in the proportion of cancer-specific CM visits (from 2.3% to 10.6%) and high-utility CM users (from 3.1% to 19.7%). Most CM services were provided by private clinics (68.1% to 79.2%). The most frequently used CM therapies were Chinese herbal medicine (72.8% to 78.8%), followed by acupuncture/traumatology manipulative therapies (28.1% to 36.8%). Total CM cost increased from $122 247 to $825 454. The average cost per CM visit increased from $14.0 to $19.6. The annual cost per CM user increased from $88.0 to $134.4. Copayment accounted for 6.6% to 11.7%.

CONCLUSIONS

There was a trend of increased CM use among prostate cancer patients under NHI. Although prostate cancer patients used CM mostly for noncancer diseases, CM visits for prostate cancer increased remarkably. The utilization patterns of CM visits for cancer and for noncancer diseases were distinctly different.

Synergistic antimicrotubule therapy for prostate cancer

Prostate cancer has been widely viewed as a chemoresistant neoplasm. Perhaps, the most prevalent antimicrotubule strategy involves docetaxel administration at its maximum-tolerated dose (MTD). Although the goal is to obtain total eradication of cancer cells, debilitating toxicities are presented by docetaxel therapy, including myelosuppression, immunosuppression, gastrointestinal toxicity and peripheral neuropathy. In addition, solubility limitations necessitate infusion of high-doses intravenously once or twice a week followed by a rest period, which allows recovery of normal proliferating cells to counter-balance efficacy. An emerging notion is that more of a toxic drug at its MTD is not necessarily better. It is likely that combinatorial antimicrotubule therapy with drugs occupying different sites on tubulin may enhance efficacy while reducing toxicity. Here we show that bromonoscapine (EM011), a microtubule-modulating noscapine analog, displays synergism with docetaxel as seen by cell viability and proliferation assays. Cell-cycle data demonstrated that lower dose-levels of docetaxel (25nM) in combination with EM011 caused an additive increase in proapoptotic activity. Since docetaxel alone caused severe mitotic arrest followed by mitotic slippage and endoreduplication, we strategized a sequential treatment regime that involved initial pretreatment with docetaxel followed by addition of EM011 to maximize mitotic arrest and subsequent apoptosis. In vivo studies with docetaxel and EM011 in combination showed a marked inhibition of tumor growth compared to docetaxel or EM011 as single-agents. Our studies suggest the potential usefulness of EM011 in the clinic to enhance docetaxel activity. This would reduce toxicity, thus improving the quality of life of docetaxel-treated patients.

Diet and dietary supplement intervention trials for the prevention of prostate cancer recurrence: a review of the randomized controlled trial evidence

PURPOSE

We review the effect of diet and dietary supplement interventions on prostate cancer progression, recurrence and survival.

MATERIALS AND METHODS

A literature search was conducted in MEDLINE, EMBASE and CINAHL to identify diet and dietary supplement intervention studies in men with prostate cancer using prostate specific antigen or prostate specific antigen doubling time as a surrogate serum biomarker of prostate cancer recurrence and/or survival.

RESULTS

Of the 32 studies identified 9 (28%) were randomized controlled trials and the focus of this review. In these studies men had confirmed prostate cancer and elevated or increasing prostate specific antigen. Only 1 trial included men with metastatic disease. When body mass index was reported, men were overweight or obese. A significant decrease in prostate specific antigen was observed in some studies using a low fat vegan diet, soy beverage or lycopene supplement. While not often reported as an end point, a significant increase in prostate specific antigen doubling time was observed in a study on lycopene supplementation. In only 1 randomized controlled trial in men undergoing orchiectomy was a survival end point of fewer deaths with lycopene supplementation reported.

CONCLUSIONS

A limited number of randomized controlled trials were identified in which diet and dietary supplement interventions appeared to slow disease progression in men with prostate cancer, although results vary. Studies were limited by reliance on the surrogate biomarker prostate specific antigen, sample size and study duration. Well designed trials are warranted to expand knowledge, replicate findings and further assess the impact of diet and dietary supplement interventions on recurrence and treatment associated morbidities.

Differences in prognostic factors and survival among white and Asian men with prostate cancer, California, 1995-2004

BACKGROUND

There are very limited data concerning survival from prostate cancer among Asian subgroups living in the U.S., a large proportion of whom reside in California. There do not appear to be any published data on prostate cancer survival for the more recently immigrated Asian subgroups (Korean, South Asian [SA], and Vietnamese).

METHODS

A study of prognostic factors and survival from prostate cancer was conducted in non-Hispanic whites and 6 Asian subgroups (Chinese, Filipino, Japanese, Korean, SA, and Vietnamese), using data from all men in California diagnosed with incident prostate cancer during 1995-2004 and followed through 2004 (n = 116,916). Survival was analyzed using Cox proportional hazards models.

RESULTS

Whites and Asians demonstrated significant racial differences in all prognostic factors: age, summary stage, primary treatment, histologic grade, socioeconomic status, and year of diagnosis. Every Asian subgroup had a risk factor profile that put them at a survival disadvantage compared with whites. Overall, the 10-year risk of death from prostate cancer was 11.9%. However, in unadjusted analyses Japanese men had significantly better survival than whites; Chinese, Filipino, Korean, and Vietnamese men had statistically equal survival; and SA men had significantly lower survival. On multivariate analyses adjusting for all prognostic factors, all subgroups except SA and Vietnamese men had significantly better survival than whites; the latter 2 groups had statistically equal survival.

CONCLUSIONS

Traditional prognostic factors for survival from prostate cancer do not explain why most Asian men have better survival compared with whites, but they do explain the poorer survival of SA men compared with whites.

Lifestyle during and after cancer treatment

The aim of this overview was to examine the evidence for links between lifestyle during and after cancer treatment and quality of life, risk of treatment side-effects, rate of progression and prevention of relapse. The reviewed studies were divided into categories according to the role lifestyle plays in progression, during treatment, and in relapse prevention. The evaluated evidence was utilised to show potential lifestyle interventions to facilitate well-being and quality-of-life initiatives. There is now persuasive evidence that dietary choice and exercise can improve the physical and psychological function of patients with cancer. There is also persuasive evidence that lifestyle choice can prevent cancer or the reoccurrence of cancer in susceptible individuals, and possibly improve survival.

Dietary agents in the chemoprevention of prostate cancer

Nutritional factors have been estimated to contribute 20-60% of cancers around the globe, and almost one-third of deaths are being reported in Western countries. According to estimates by the American Cancer Society, during the year 2005 about 232,090 new cases of prostate cancer will be diagnosed alone in the United States and 30,350 men will die of this disease. The high incidence and long latency period of prostate cancer offer plenty of time to pursue strategies toward prevention and/or treatment to suppress or revert this disease. Epidemiological evidence suggests that plant-based dietary agents decrease the risk of some types of human cancer, including prostate cancer. Intake of 400-600 g/day of fruits and vegetables is associated with reduced risk of several cancers. The use of micronutrients and/or other phenolic agents in the diet or synthetic exogenous supplements to prevent neoplastic transformation of normal cells or to slow the progression of established malignant changes in cancer cells is termed "chemoprevention." Considerable attention has been devoted to identify plant-based dietary agents that may serve as natural inhibitors of prostate carcinogenesis. Much progress has been made in the last decade in this area of investigation through identification of pathways that play important roles in prostate tumorigenesis. This article summarizes epidemiological, clinical, and mechanistic studies and the significance of plant-derived dietary agents such as flavonoids, indoles, isothiocyanates, phenolics, monoterpenes, and complementary and alternative agents in the management of prostate cancer with recommendations for future studies to advance this area of research.

Use of complementary therapies among breast and prostate cancer patients during treatment: a multisite study

PURPOSE

The purpose of this study was to compare the use of complementary therapies (CT) among breast and prostate cancer patients during active cancer treatment. The authors compared use and beliefs about the role of CT in cancer recovery.

METHODS

A self-report survey was completed by 126 breast cancer patients and 82 prostate cancer patients as part of a multisite research project. The self-report questionnaire inquired about the use of various CTs, sources of information about CT, reasons for using CT, beliefs about the benefits and risks of CT, demographic characteristics, and cancer treatment history.

RESULTS

Most of the respondents were older than 50 years, Caucasian, married, had attended or completed college, and were less than 1 year post-diagnosis. Prostate cancer patients were significantly older than the breast cancer patients (P < .001). Several differences emerged between the groups. Compared to the prostate cancer patients, significantly more of the breast cancer patients reported using CT because they wanted to reduce the risk of recurrence (P < .01), play a more active role in recovery (P < .01), help manage stress (P < .01), take a more holistic approach (P < .01), or boost the immune system (P < .01). More of the prostate cancer patients reported using CT to have more control of their recovery (P < .05). The 2 groups also differed significantly (P < .01) on several beliefs about the potential benefits and risks of using CT.

CONCLUSIONS

Most of the patients in this study had used some form of CT since the time of their diagnosis. Differences among breast and prostate cancer patients with regard to their use of CT during cancer treatment should be considered by oncology professionals who are discussing this topic with their patients.

Total and specific complementary and alternative medicine use in a large cohort of men with prostate cancer

OBJECTIVES

To assess specific complementary and alternative medicine (CAM) use in the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE), a large, community-based national registry of men with prostate cancer.

METHODS

We examined more than 50 types of CAM use in a large, national, community-based registry of men with prostate cancer (CaPSURE). Participants completed biannual surveys within 2 years of diagnosis and treatment. We analyzed associations of CAM use with sociodemographic and clinical features, using chi-square tests and multivariate logistic regression.

RESULTS

One third of 2582 respondents reported using CAM. Common practices included vitamin and mineral supplements (26%), herbs (16%), antioxidants (13%), and CAM for prostate health (12%; eg, saw palmetto, selenium, vitamin E, lycopene). In multivariate analyses, users were more likely to have other comorbid conditions, worse cancer grade at diagnosis, higher incomes, more education, and to live in the West.

CONCLUSIONS

Complementary and alternative medicine use was associated with sociodemographic and clinical characteristics in this large sample of men with prostate cancer. These results should be considered by health care professionals counseling men with prostate cancer regarding diet and secondary prevention.

Opening the dialogue: Herbal supplementation and chemotherapy

Presently, healthcare providers have little scientific evidence on which to base recommendations about use of herbal supplements with chemotherapy. Lack of product standardization and definitive knowledge about herb interaction with chemotherapy may expose patients with cancer to potentially serious side effects. Patients continue to use herbal supplements with their cancer treatments, often without informing their healthcare providers. Research currently is ongoing to study the effects of the concomitant administration of herbal supplements and chemotherapy.

The tomato as a functional food

Tomatoes are the fourth most commonly consumed fresh vegetable and the most frequently consumed canned vegetable in the American diet. There is emerging epidemiology data supporting the connection between increased tomato consumption and reduced risk for both cardiovascular disease and prostate cancer. Here we will summarize the nutrient and the phytochemical content of tomatoes and tomato products, and how these bioactive components might act together to modulate disease development. Recent animal studies have investigated tomatoes, lycopene, and prostate cancer using the N-methyl-N-nitrosourea and Dunning rat models. These animal studies also suggest that diets containing tomatoes may decrease the risk or the progression of prostate cancer. Due to the frequency and the extent of tomato consumption, the supporting epidemiological and animal data, which connect increased intakes with decreased cancer and cardiovascular disease risk, tomato's role in the American diet is of undeniable importance as part of a healthy diet.

A hidden cause of hypokalemic paralysis in a patient with prostate cancer

Hypokalemic paralysis is a medical emergency due to the risks of cardiac arrhythmia, respiratory failure, and rhabdomyolysis. Besides supplementing patients with KCl to hasten recovery, the astute physician must search for the underlying cause to avoid missing a treatable and curable disorder. We report on an elderly Korean man who presented with marked limb paralysis, myalgias, and mild hypertension. He had prostate cancer treated with orchiectomy and hormone therapy 2 years previously. The major biochemical abnormalities were hypokalemia (K+: 1.7 mmol/l) associated with high renal K+ wasting and metabolic alkalosis (HCO3-: 42.6 mmol/l). Low plasma renin activity, low aldosterone concentration, and normal cortisol concentration pointed to a state of pseudohyperaldosteronism. While reviewing his drug history, the patient revealed he had been consuming eight packs (100 ml/pack) of a Korean herbal tonic daily to treat his prostate cancer for the past 2 months. A significant amount of glycyrrhizic acid (0.23 mg/ml), an active ingredient of licorice, was detected in the tonic. Discontinuation of the herbal tonic along with KCl supplementation achieved recovery in 2 weeks. As many complementary/alternative medicines for cancer contain licorice, this must be kept in mind as a cause of hypokalemia in cancer patients.

Herbal remedies in the United States: potential adverse interactions with anticancer agents

PURPOSE

Interest in the use of herbal products has grown dramatically in the Western world. Recent estimates suggest an overall prevalence for herbal preparation use of 13% to 63% among cancer patients. With the narrow therapeutic range associated with most anticancer drugs, there is an increasing need for understanding possible adverse drug interactions in medical oncology.

METHODS

In this article, a literature overview is provided of known or suspected interactions of the 15 best-selling herbs in the United States with conventional allopathic therapies for cancer.

RESULTS

Herbs with the potential to significantly modulate the activity of drug-metabolizing enzymes (notably cytochrome p450 isozymes) and/or the drug transporter P-glycoprotein include garlic (Allium sativum), ginkgo (Ginkgo biloba), echinacea (Echinacea purpurea), ginseng (Panax ginseng), St John' s wort (Hypericum perforatum), and kava (Piper methysticum). All of these products participate in potential pharmacokinetic interactions with anticancer drugs.

CONCLUSION

It is suggested that health care professionals and consumers should be aware of the potential for adverse interactions with these herbs, question their patients on their use of them, especially among patients whose disease is not responding to treatments as expected, and urge patients to avoid herbs that could confound their cancer care.

Environmental, genetic, and molecular features of prostate cancer

Prostate cancer is the sixth most common cancer in the world and the third leading cause of cancer in men. The increase in the understanding of prostate carcinogenesis over the past 15 years has helped to define crucial steps in the natural history of the disease, namely initiation and progression to androgen independence. This heterogeneous disease encompasses a range of environmental and familial factors, which provides strong support for the use of chemopreventive strategies. Most patients with advanced prostate cancer are treated with androgen-deprivation therapy, which leads to a striking regression of androgen-responsive cancer cells. A transition from an androgen-responsive to an androgen-unresponsive stage is seen during the clinical course in almost all patients with prostate cancer. This transition also signals a substantial worsening of prognosis. Here, we review the most important findings in prostate carcinogenesis and the molecular anomalies associated with the androgen-refractory stage.

Estrogens and anti-estrogens: Key mediators of prostate carcinogenesis and new therapeutic candidates

Despite the historical use of estrogens in the treatment of prostate cancer (PCa) little is known about their direct biological effects on the prostate, their role in carcinogenesis, and what mechanisms mediate their therapeutic effects on PCa. It is now known that estrogens alone, or in synergism with an androgen, are potent inducers of aberrant growth and neoplastic transformation in the prostate. The mechanisms of estrogen carcinogenicity could be mediated via induction of unscheduled cell proliferation or through metabolic activation of estrogens to genotoxic metabolites. Age-related changes and race-/ethnic-based differences in circulating or locally formed estrogens may explain differential PCa risk among different populations. Loss of expression of estrogen receptor (ER)-beta expression during prostate carcinogenesis and prevention of estrogen-mediated oxidative damage could be exploited in future PCa prevention strategies. Re-expression of ER-beta in metastatic PCa cells raises the possibility of using ER-beta-specific ligands in triggering cell death in these malignant cells. A variety of new estrogenic/anti-estrogenic/selective estrogen receptor modulator (SERM)-like compounds, including 2-methoxyestradiol, genistein, resveratrol, licochalcone, Raloxifene, ICI 182,780, and estramustine are being evaluated for their potential in the next generation of PCa therapies. Increasing numbers of patients self-medicate with herbal formulations such as PC-SPES. Some of these compounds are selective ER-beta ligands, while most of them have minimal interaction with ER-alpha. Although many may inhibit testosterone production by blockade of the hypothalamal-pituitary-testis axis, the most effective agents also exhibit direct cytostatic, cytotoxic, or apoptotic action on PCa cells. Some of them are potent in interfering with tubulin polymerization, blocking angiogenesis and cell motility, suppressing DNA synthesis, and inhibiting specific kinase activities. Further discovery of other compounds with potent apoptotic activities but minimal estrogen action should promote development of a new generation of effective PCa preventive or treatment regimens with few or no side-effects due to estrogenicity. Further advancement of our knowledge of the role of estrogens in prostate carcinogenesis through metabolic activation of estrogens and/or ER-mediated pathways will certainly result in better preventive or therapeutic modalities for PCa.