Clinical trials of breast and prostate cancer prevention

The janus face of lipids in human breast cancer: how polyunsaturated Fatty acids affect tumor cell hallmarks

For several years, lipids and especially n - 3 and n - 6 polyunsaturated fatty acids (PUFAs) receive much attention in human health. Epidemiological studies tend to correlate a PUFA-rich diet with a reduced incidence of cancer, including breast cancer. However, the molecular and cellular mechanisms supporting the effect of PUFAs in breast cancer cells remain relatively unknown. Here, we review some recent progress in understanding the impact that PUFA may have on breast cancer cell proliferation, apoptosis, migration, and invasion. While most of the results obtained with docosahexaenoic acid and/or eicosapentaenoic acid show a decrease of tumor cell proliferation and/or aggressivity, there is some evidence that other lipids, which accumulate in breast cancer tissues, such as arachidonic acid may have opposite effects. Finally, lipids and especially PUFAs appear as potential adjuvants to conventional cancer therapy.

Diet assessment methods: a guide for oncology nurses

Diet may play a significant role in cancer prevention, disease progression, and treatment tolerance. An in-depth search of the literature revealed limited information geared toward nurses about diet assessment methods used in research. The purpose of this review is to synthesize the evidence regarding diet assessment methods important in oncology studies. The method used varied based on the study size, duration, and research question. For example, studies focusing on mean nutrient intake of a group used a 24-hour dietary recall, estimated food diary or dietary record, or food frequency questionnaire. Studies investigating usual nutrient intake predominately used multiple 24-hour dietary recalls, dietary records, biomarkers, or food frequency questionnaires. Measuring dietary intake accurately in a cost-effective manner is a difficult task. Selection of the appropriate assessment tool is critical for the generation of quality data. Oncology nurses are increasing their involvement in nutrition research, and the findings from this review may promote a better understanding of the published and ongoing research in this important field of study.

Molecular effects of soy phytoalexin glyceollins in human prostate cancer cells LNCaP

Glyceollins are soy-derived phytoalexins that have been proposed to be candidate cancer preventive compounds. The effect of the glyceollins on prostate cancer is unknown. The present study examined the molecular effects of soy phytoalexin, glyceollins, on human prostate cancer cell LNCaP to further elucidate its potential effects on prostate cancer prevention. We found that the glyceollins inhibited LNCaP cell growth similar to that of the soy isoflavone genistein. The growth inhibitory effects of the glyceollins appeared to be due to an inhibition of G1/S progression and correlated with an up-regulation of cyclin-dependent kinase inhibitor 1 A and B mRNA and protein levels. By contrast, genistein only up-regulates cyclin-dependent kinase inhibitor 1A. In addition, glyceollin treatments led to down-regulated mRNA levels for androgen responsive genes. In contrast to genistein, this effect of glyceollins on androgen responsive genes appeared to be mediated through modulation of an estrogen- but not androgen-mediated pathway. Hence, the glyceollins exerted multiple effects on LNCaP cells that may be considered cancer preventive and the mechanisms of action appeared to be different from other soy-derived phytochemicals.

Molecular signatures of soy-derived phytochemicals in androgen-responsive prostate cancer cells: a comparison study using DNA microarray

The present study utilized microarray technology as a tool to elucidate the molecular signatures of soy-derived phytochemicals in the human androgen-responsive prostate cancer cell line LNCaP. Global gene expression pattern analysis of LNCaP cells exposed to 0, 1, 5, or 25 microM of the soy-derived phytochemicals equol and daidzein were conducted and compared. The data were further compared with previously generated data from exposure of LNCaP cells to the same doses of genistein, a soy isoflavone. Multidimensional scaling (MDS) analyses of the expression patterns suggest that these compounds exerted differential effects on gene expression in LNCaP cells. Further examination of specific gene changes revealed that these compounds differentially modulated genes in multiple cellular pathways, including the cell-cycle pathway genes. However, the three compounds also exerted similar effect on genes belonging to several other important cellular pathways. A universal effect of the three compounds on androgen-responsive genes, IGF-1 pathway gene, and MAP kinase-related pathway gene was observed. These results provide the foundation for establishing molecular signatures for equol, daidzein, and genistein. Moreover, these results also allow for the identification of candidate mechanism(s) by which soy phytochemicals and soy may act in prostate cancer cells.

Prevalence and patterns of self-initiated nutritional supplementation in men at high risk of prostate cancer

OBJECTIVE

To define the prevalence and patterns of self-initiated herbal and vitamin supplementation among men at high risk of developing prostate cancer, as there is increasing public awareness of prostate cancer screening, risk-factor assessment and prevention, leading to increasing interest in the use and systematic study of nutritional therapies for prostate cancer prevention.

SUBJECTS AND METHODS

Since 1996 our institution has prospectively maintained a prostate cancer-risk registry through its Prostate Cancer Risk Assessment Program (PRAP). Eligibility includes African-American men, any man with at least one first-degree relative or two or more second-degree relatives with prostate cancer, or men who tested positively for the BRCA1 gene mutation. A 420-item self-administered questionnaire was completed and included the use of nutritional supplements and complementary therapies. We divided men into groups who used supplements to lessen their cancer risk and those who did not. The prevalence and patterns of use were evaluated and the two groups then compared for differences in demographic, socio-economic and risk-perception variables.

RESULTS

In all, 345 high-risk men were enrolled in the PRAP over a 5-year period. Data on the use of dietary or herbal supplements were available on 333 men (97%), of whom over half (170) reported taking one or more supplements to prevent prostate cancer. Supplement use was divided into eight categories, including vitamins, minerals, extracts from fruits/seeds, organic compounds, flowers/bulbs, leaves/bark, roots, or animal products. Most commonly used for self-initiated chemoprevention were vitamins (95%), minerals (28%), and fruit/seed extracts (18%). More than a quarter of men (27%) took three or more agents. Men taking proactive preventative measures were statistically more likely to be Caucasian and aged > 60 years (P < 0.05). African-Americans were less likely to self-initiate preventative steps. Men taking supplements tended to return more often for follow-up and participate in PRAP longer, while those not taking supplements tended to earn less and report less self-perceived risk.

CONCLUSIONS

A significant proportion of men at risk of developing prostate cancer initiate measures they perceive to reduce their risk. Although the chemopreventative efficacy of many of these supplements remains unsubstantiated, they are widely perceived by the public to reduce the risk of developing prostate cancer. These data provide an insight into patient perceptions and misconceptions of chemopreventative strategies, and may help to refine recruitment efforts in multi-institutional prostate cancer prevention trials.