Complementary and alternative medicine use among women at increased genetic risk of breast and ovarian cancer

Use of complementary and alternative medicines (CAM) among Malaysian cancer patients for the management of chemotherapy related side effects (CRSE)

OBJECTIVES

Chemotherapy-related side effects (CRSE) are among the most distressing events cancer patients face. Some patients seek complementary and alternative medicines (CAM), increasing the risk of undesirable drug- CAM interactions. This study aims to identify the prevalence and type of CAM used for CRSE among cancer patients and patient's disclosure of CAM use to their prescribers.

METHODS

This was a questionnaire-based, cross-sectional study. Data was collected from cancer patients attending to three departments: surgical, medical and gynaecology at a local hospital in Malaysia. Ethical approval was obtained from the Medical Research Ethics Committee, Ministry of Health, Malaysia.

RESULTS

A total of 273 patients were recruited. Prevalence of CAM used for CRSE management was 166 (60.8%). Of the CAM users, 144 (86.7%) were female, 102 (61.4%) were employed and 123 (74.1%) were married. Breast cancer patients were found to be the highest users of CAM (n=76; 45.8%). The top three CAM used by patients in managing CRSE were dietary supplements (n=166; 100%); herbal products (n=154; 92.8%) and traditional Malay therapy (n=147; 88.6%). About 83% (n=137) patients disclosed CAM use to their prescribers. Among these, 58 (42.3%) reported that their doctors encouraged the use, whereas 89 (65.0%) patients claimed their doctors disagreed the use of CAM.

CONCLUSIONS

Prescribers still have doubt in combining chemotherapy with CAM, hence patients use CAM discreetly. Increasing the awareness and understanding of CAM use are mandatory to distinguish its possible synergistic or adverse reactions with cancer patients.

Contextualizing geneticization and medical pluralism: How variable institutionalization of traditional, complementary, and alternative medicine (TCAM) conditions effects of genetic beliefs on utilization

As genetic models are increasingly incorporated in medicine, health service users seem to accept these models to varying degrees. To appreciate these differences, this paper examines how health service users' genetic beliefs of health are associated with their use of traditional, complementary, and alternative medicine (TCAM) via responses from 31 countries in the 2011 ISSP survey. It finds an interesting contrast between East Asian countries and other countries in the world. The negative association between genetic beliefs and TCAM use is strong in the latter, whereas it is weak in the former. More intriguingly, the analysis demonstrates significant cross-national differences within East Asian countries. Chinese and Koreans reveal a negative relationship between genetic beliefs and TCAM use, while Japanese show a positive relationship. The paper provides an explanation to these cross-national differences by drawing on comparative studies of medical systems. When TCAM is institutionalized as valid and distinct medical resources, and when TCAM is practically available to everyday use, health service users who subscribe to genetic beliefs are likely to use TCAM as well. These findings contribute to revealing the pragmatic nature of health-seeking action and the institutional context in which geneticization and medical pluralism are conditioned to form.

Utilization of Complementary Alternative Medicine, Diet, and Exercise Among Women at High Risk for Developing Breast Cancer

Background: Women diagnosed as having a high risk for breast cancer (HR-BC) often seek different health behaviors (HBs) such as complementary and alternative medicine (CAM), diet, and exercise to improve their health and cancer outcome. Methods: Women already enrolled in a multimodality screening study for patients at HR-BC (gene mutation carrier or >20% cumulative lifetime risk) were given a questionnaire to evaluate their use of CAM therapies, diet, and exercise before and after a diagnosis of HR-BC. Patients were also asked to complete the Short-Form 36, State-Trait Anxiety Inventory, and Beck Depression Inventory. Results: A total of 134 (67%) subjects completed the survey from the original cohort. General characteristics included a median age of 46 years (range = 24-73 years), majority were White (91%), BRCA1/2 gene mutation carrier (49%), and prior diagnosis of breast and/or ovarian cancer (30%). Almost all of the patients reported a lifetime prevalence of any HB (97%) and CAM utilization (91%). Subjects also had a high lifetime utilization of exercise (83%), herbs and supplements(72%), and diet programs (58%). All of these HBs declined in utilization after diagnosis of HR-BC by as much as 30%. After diagnosis of a HR-BC, a personal history of breast and/or ovarian cancer was significantly correlated with increased use of CAM (odds ratio [OR] = 5.9, P < .01), herbs and supplements (OR = 4.3, P < .01), and diet program (OR = 4.4, P < .01) in multivariate analysis. Conclusions: HBs such as CAM, diet, and exercise are highly prevalent among women with HR-BC, and the utilization of HB decreases significantly after diagnosis of HR-BC.

High use of complementary and alternative medicine among a large cohort of women with a family history of breast cancer: the Sister Study

Use of complementary and alternative medicine (CAM) is high among U.S. women, yet information is limited on use among women at increased breast cancer risk. We analyzed CAM use among women with a family history of breast cancer. CAM use was analyzed among women enrolled 2003-2009 in the Sister Study cohort. Eligible women were aged 35-74, U.S. or Puerto Rican residents, no personal history of breast cancer, and had ≥1 sister with breast cancer. Baseline data on CAM use in the past year were available for 49,734 women. Logistic regression models examined the association between CAM use and Gail Model breast cancer risk score. Results were compared to female participants in the 2007 National Health Interview Survey (n = 7965). Among Sister Study participants, there was high use of vitamin/mineral supplements (79 %), mind-body practices (41 %), manipulative/body-based practices (32 %), and botanicals (23 %). Overall use was higher than the U.S. female population. No association was observed between familial breast cancer risk and CAM use. Black women were more likely to use spirituality/meditation-based CAM modalities, while non-Hispanic white and Asian women were high users of dietary supplements. In a cohort of women with increased breast cancer risk due to family history, CAM use is higher than women in the general U.S. population and is associated with race/ethnicity. Use was not associated with breast cancer risk. Given the high prevalence of CAM use among women at risk for breast caner, research on the effectiveness of CAM use for disease prevention is needed.

Positive effects of oral β-glucan on mucositis and leukopenia in colorectal cancer patients receiving adjuvant FOLFOX-4 combination chemotherapy

The present study aimed to determine the effect of oral β-glucan on mucositis and leukopenia in 62 consecutive patients with colorectal cancer treated with an adjuvant FOLFOX-4 regimen. The patients were retrospectively evaluated in 2 groups: one group received β-glucan and the other did not (control group). Leucocytes, neutrophils, and platelets were evaluated before and 1 week after chemotherapy and oral mucositis and diarrhea were noted. Leucocyte and neutrophil counts after chemotherapy in the β-glucan group were 7,300/mm3 and 3,800/mm3, respectively, and the reductions, as compared to baseline, were not significant (p=0.673 and 0.784). The median platelet count was 264,000/mm3 after chemotherapy in the β-glucan group and the reduction, as compared to baseline, was borderline significant (p=0.048). In the control group, reduction in leucocyte, neutrophil, and platelet counts was statistically significant. Oral mucositis and diarrhea were less common in the β-glucan group. We conclude that β-glucan can be used to reduce the adverse effects of chemotherapy.

Hot flashes severity, complementary and alternative medicine use, and self-rated health in women with breast cancer

CONTEXT

Hot flashes (HF) are a common distressing symptom in women with breast cancer (BC). Current pharmacologic options are moderately effective and are associated with bothersome side effects. Complementary and alternative medicine is commonly used by cancer patients. However, information on the association of hot flashes severity with such use and self-rated health is lacking.

OBJECTIVE

To examine the hot flashes severity in women with breast cancer and its association with complementary and alternative medicine use and self-rated health (SRH).

DESIGN

Longitudinal multicenter study to assess information needs of cancer outpatients.

PARTICIPANTS

Patients with a diagnosis of breast cancer who were scheduled to undergo chemotherapy and/or radiotherapy.

OUTCOME MEASURES

Hot flashes severity (0 = not present and 10 = as bad as you can imagine), use of complementary and alternative medicine (yes/no), and self-rating of health (SRH) status post-treatment and six-months thereafter (1-5, higher score = better SRH).

RESULTS

The majority of women with HF (mean age = 54.4 years) were Caucasian and married, with higher education, and 93% had received surgical treatment for BC. At the end of treatment, 79% women reported experiencing HF [mean severity = 5.87, standard deviation (SD) = 2.9]; significantly more severe HF were reported by younger women with poor SRH, poor performance status, and those reporting doing spiritual practices. At follow-up, 73% had HF (mean severity = 4.86, SD = 3.0), and more severe HF were reported by younger women with poor self-rated health who had undergone chemotherapy plus radiotherapy, used vitamins, and did not exercise.

CONCLUSIONS

A high percentage of women experienced hot flashes at the end of treatment and at six-month follow-up. A significant association of hot flashes severity with spiritual practice, increased vitamin use, and reduced exercise emphasize the need for future studies to confirm the results. This can facilitate safe use of complementary and alternative medicine and favorable outcomes while managing cancer-related hot flashes.

A single-center, randomized double-blind placebo-controlled study evaluating the effects of poly-gamma-glutamate on human NK cell activity after an 8-week oral administration in healthy volunteers

A randomized double-blind placebo-controlled immunity study involving 99 healthy volunteers was performed to investigate the effect of poly- γ -glutamate ( γ -PGA) on human natural killer (NK) cell activity in peripheral blood. The volunteers were randomly assigned to one of three groups and orally treated with solutions (25 mL) containing 0 mg (placebo), 250 mg (low dosage), or 500 mg (high dosage) of γ -PGA. Each volunteer took one dose every 12 hours for 8 weeks. Blood samples were drawn before the initial treatment and at the 4th and the 8th weeks of treatment. NK cell activity was assessed by measuring its degranulation, cytokine production, and cytotoxicity against the K562 cell line. Our results revealed that the cytotoxic activities of NK cells from the high-dosage γ -PGA group were significantly higher (P < 0.05 for all comparisons) compared to the low dosage and placebo groups at weeks 4 and 8 after the initial treatment. This increase in the NK cell activity among peripheral blood mononuclear cells (PBMCs) of healthy individuals was also confirmed in vitro (as assessed by the degranulation and cytokine production). These results suggest that the oral administration of γ -PGA induces a cell-mediated immunity by increasing the NK cell activity in humans.

Adverse events associated with complementary and alternative medicine use in ovarian cancer patients

INTRODUCTION

Many women with ovarian cancer are choosing to include complementary and alternative medicine (CAM) substances in conjunction with their conventional treatment for ovarian cancer. Many oncologists express concern that the adjunct use of CAM substances may be detrimental to the achievement of therapeutic levels of chemotherapy leading to increases in drug toxicity, under-treatment of disease or other adverse events. In an effort to ascertain the extent of the potential problem with simultaneous use of CAM with conventional treatment we undertook comprehensive systematic review of published case reports describing CAM-related adverse events among ovarian cancer patients.

STUDY DESIGN

This article describes a systematic literature review.

METHODS

The Natural Medicines Comprehensive Database (NMCD). PubMed, EMBASE® and the Cochrane Central Register of Controlled Trials (CCTR) were systematically reviewed for research articles pertaining to case reports describing adverse events in patients, and clinical trials which examined the effects of herbs and supplements used during cancer treatment.

RESULTS

Only one case report and one clinical trial were identified which met our inclusion criteria and were relevant to the current investigation.

CONCLUSION

Although there are concerns about the potential for adverse events related to concurrent use of CAM substances during conventional treatment we found few case reports and clinical trials in the literature which support this.

The Relationship between Complementary and Alternative Medicine Use and Breast Cancer Early Detection: A Critical Review

Objective. Complementary and alternative medicine (CAM) use is prevalent. Concurrently, breast cancer is the most common cancer in women worldwide, with early detection techniques widely available. This paper examined the overlap between participation in allopathic breast cancer early detection activities and CAM use. Methods. A systematic review examined the association between breast screening behaviors and CAM use. Searches were conducted on the PubMed, Embase, CINAHL, and NCCAM databases and gray literature between 1990 and 2011. STROBE criteria were used to assess study quality. Results. Nine studies met the search criteria. Four focused on CAM use in women at high breast cancer risk and five on average risk women. CAM use in women ranged from 22% to 82% and was high regardless of breast cancer risk. Correlations between CAM use and breast cancer early detection were not strong or consistent but significant relationships that did emerge were positive. Conclusions. Populations surveyed, and measures used to assess CAM, breast cancer screening, and correlates, varied widely. Many women who obtained allopathic screening also sought out CAM. This provides a foundation for future interventions and research to build on women's motivation to enhance health and develop ways to increase the connections between CAM and allopathic care.

Use of complementary and alternative medicine for physical performance, energy, immune function, and general health among older women and men in the United States

We examined use of complementary and alternative medicine (CAM) for health and well-being by older women and men. Data were from the 2007 National Health Interview Survey, representing 89.5 million Americans ages 50+. Multivariate logistic regression accounted for the survey design. For general health, 52 million people used CAM. The numbers for immune function, physical performance, and energy were 21.6, 15.9, and 10.1 million respectively. In adjusted results, women were much more likely than men to use CAM for all four reasons, especially energy. Older adults, particularly women, could benefit from research on CAM benefits and risks.

Predictors of Use of Complementary and Alternative Medicine by Non-Hodgkin Lymphoma Survivors and Relationship to Quality of Life

Hypotheses. This study hypothesized that non-Hodgkin lymphoma (NHL) patients who used complementary and alternative medicine (CAM) would have higher health-related quality of life (HRQOL) and a greater perceived sense of control than nonusers. However, since CAM may predict HRQOL, and perceived control may be both associated with CAM use as well as being an independent predictor of HRQOL, the authors also sought to test whether perceived control mediated the relationship between CAM use and HRQOL. Study design. This was a cross-sectional study design. NHL survivors diagnosed between June 1, 1998 and August 31, 2001 were selected from the population-based SEER (Surveillance, Epidemiology, and End Results) cancer registry for Los Angeles County and were mailed a survey in 2003 that assessed CAM use and predictors of CAM use. The response rate was 54.8%; 319 provided complete data for analysis. Methods. Categories of CAM were defined according to the National Center for Complementary and Alternative Medicine guidelines. The authors measured survivors’ cancer-related control using the Perceived Personal Control scale, a 4-question scale that was adapted from previously validated scales. HRQOL was measured using the mental component summary and physical component summary scores from the SF-36 v2.0. Bivariate and multivariable logistic and linear regression models were used to assess factors associated with CAM use and the association of CAM use with psychosocial health outcomes, respectively. Results. Sixty-one percent of respondents reported using at least one CAM modality within the past 4 weeks, and 40% did so after excluding personal prayer and support groups. Younger age and higher education were significantly associated with greater CAM use as were higher perception of cancer-related control ( P = .004) and more positive mental functioning ( P = .016). Perception of control significantly mediated the association between CAM use and mental functioning ( P < .001). Conclusions. CAM use may be related to more positive mental health–related quality of life by increasing patients’ perception of perceived control over their health; however, cause and effect cannot be determined. Physicians should be aware that cancer survivors have a need to take an active role in improving their health.

Use of Chinese medicine by cancer patients: a review of surveys

Chinese medicine has been used to treat a variety of cancer-related conditions. This study aims to examine the prevalence and patterns of Chinese medicine usage by cancer patients. We reviewed articles written in English and found only the Chinese medicine usage from the studies on complementary and alternative medicine (CAM). Seventy four (74) out of 81 articles reported rates of CAM usage ranging from 2.6 to 100%. Acupuncture was reported in 71 out of 81 studies. Other less commonly reported modalities included Qigong (n = 17), Chinese herbal medicine (n = 11), Taichi (n = 10), acupressure (n = 6), moxibustion (n = 2), Chinese dietary therapy (n = 1), Chinese massage (n = 1), cupping (n = 1) and other Chinese medicine modalities (n = 19). This review also found important limitations of the English language articles on CAM usage in cancer patients. Our results show that Chinese medicine, in particular Chinese herbal medicine, is commonly used by cancer patients. Further research is warranted to include studies not written in English.

Use of multivitamins, folic acid and herbal supplements among breast cancer survivors: the black women's health study

BACKGROUND

Complementary and alternative medicine (CAM) use, including herbals and multivitamin supplements, is quite common in the U.S., and has been shown to be highest in breast cancer survivors. However, limited data are currently available for CAM usage among African Americans. Thus, we sought to determine the prevalence of multivitamins, folic acid and herbal supplement usage in African American breast cancer survivors, and to compare the characteristics of users and nonusers.

METHODS

A cohort study of breast cancer survivors, who completed the 1999 Black Women's Health Study questionnaire and self-reported having been diagnosed with breast cancer between 1995 and 1999, comprised the study population. In this study, the intake of natural herbs, multivitamins and folic acid at least three days per week within the past two years was used as a proxy for typical usage of this complimentary alternative medicine (CAM) modality.

RESULTS

A total of 998 breast cancer survivors were identified. Overall, 68.2% had used either herbals or multivitamin supplements or both. The three most frequently used herbals were garlic (21.2%), gingko (12.0%), and echinacea (9.4%). The multivariate analysis determined that single marital status (OR=1.58; 95%CI: 1.04-2.41), and alcohol consumption of 1-3 drinks per week (OR=1.86, 95%CI: 1.28-2.68) were significantly associated with increased herbal use. Multivitamin use was significantly lower among obese women (OR=0.66, 95%CI: 0.46-0.94) and current smokers (OR=0.53, 95%CI: 0.34-0.82).

CONCLUSIONS

A significant number of African American breast cancer survivors are using herbals and multivitamins as CAM modality. Additional research is needed to understand the impact of herbals and multivitamins in African American breast cancer survivors.

Beliefs of New Zealand doctors about integrative medicine for cancer treatment

AIMS. This study aimed to give an up-to-date description of the views and knowledge that health professionals in New Zealand (NZ) have about complementary and alternative medicine (CAM) and its use in the context of integrative medicine.

STUDY DESIGN

A self-administered questionnaire.

METHODS

Doctors in the Otago region of New Zealand (n = 235 out of 395, 59% response rate) answered questions addressing attitudes toward the principle of integrative medicine, attitudes indigenous Ma-ori holistic views of health, and attitudes about CAM. Information on physician demographics was also gathered.

RESULTS

Almost all doctors (95%) agreed that they should address all aspects of a patient's health, whereas around 60% agreed that CAM can be integrated into a treatment regime to provide the best care for a patient. Most (93%) agreed that in a NZ context, it is important to be aware of Ma-ori holistic views of health. Doctors had many concerns about CAM, and only 26% personally used any CAM therapies themselves. However, many doctors wanted to learn more about CAM (58%) and Ma-ori holistic views of health (62%). Doctors who believed that they "knew enough" about CAM were more likely to ask about it and to recommend it to patients.

CONCLUSION

Integrative medicine is increasingly being accepted in medical practice, although many doctors still do not agree with the use of CAM. There is a need for increased patient-doctor discussions of CAM use. Doctors' lack of knowledge about CAM may be a barrier to communication and should be addressed with specific medical training.

Hormone replacement therapy in gynecologic cancer survivors: why not?

PURPOSE

As a result of treatment, many women with gynecologic malignancies will go through menopause and display climacteric symptoms at an earlier age than occurs naturally. Iatrogenic menopause may adversely affect quality of life and health outcomes in young female cancer survivors. Hormone replacement therapy (HRT) has often been withheld from women with gynecologic cancer because of concern that it might increase the risk of relapse or the development of new primary cancers. The purpose of this review was to examine the published literature on menopause management in gynecologic cancer survivors and highlight the risks and benefits of conventional and alternative HRT in this population.

METHODS

A comprehensive literature search of English language studies on menopause management in gynecologic cancer survivors and women with a hereditary predisposition to a gynecologic malignancy was performed in MEDLINE databases through December 2010.

RESULTS

Both our review and a 2008 Cochrane review of randomized trials on the effects of long-term HRT demonstrate that for menopausal women in their 40s or 50s with and without gynecologic cancer, the absolute risks of estrogen-only HRT are low. Several prospective observational studies and randomized trials on HRT use in women with a genetic predisposition for or development of a gynecologic malignancy suggest benefits in quality of life with no proven adverse oncologic effects as a result of short-term HRT use.

CONCLUSION

In select women, it is reasonable to discuss and offer conventional HRT for the amelioration of menopausal symptoms and to improve quality of life. HRT does not appear to increase the risk of gynecologic cancer recurrences; however, this conclusion was largely based on observational data and smaller prospective studies.

Diet and predictors of dietary intakes in women with family history of breast and/or ovarian cancer

BACKGROUND

Dietary intakes of vegetable, fruit, fiber, folate, and B vitamins have been associated with reduced breast and/or ovarian cancer risk. However, few studies have assessed dietary intakes and factors associated with diet in women with family history of breast and/or ovarian cancer (FHBOC). We examined dietary intakes and predictors of diet in women with FHBOC (n=211) enrolled in a population-based cancer family registry.

METHODS

We assessed diet via a food frequency questionnaire, family history by telephone and demographic variables by questionnaire. Descriptive statistics were performed, and multivariate linear regression analyses were conducted to examine variables [body mass index (BMI), age, parity, energy intake, alcohol use, smoking and education] associated with dietary intakes.

RESULTS

Mean daily intakes were: 2.57 vegetable servings [+/-standard deviation (SD) 1.22], 1.56 fruit servings (+/-0.9), 11.21g fiber (+/-5.32) and 33.85% energy from fat (+/-9.05), 241.98microg folate (+/-120.80) and 1.33mg vitamin B6 (+/-0.62). Regression analyses showed that younger age, smoking, lower education and higher BMI had a significant association with decreasing vegetable, fruit and/or fiber intakes. BMI had a significant positive association with % energy from fat. Similar results were observed when assessing independent variables with micronutrient intakes studied.

CONCLUSIONS

These data suggest that women with FHBOC should be encouraged to meet dietary guidelines for cancer prevention. Specifically, public health dietary interventions should target women with FHBOC who are smokers, less educated, have a higher BMI and are younger. Such interventions may potentially reduce breast and/or ovarian cancer risk in this population.

Characteristics of health information gatherers, disseminators, and blockers within families at risk of hereditary cancer: implications for family health communication interventions

OBJECTIVES

Given the importance of the dissemination of accurate family history to assess disease risk, we characterized the gatherers, disseminators, and blockers of health information within families at high genetic risk of cancer.

METHODS

A total of 5466 personal network members of 183 female participants of the Breast Imaging Study from 124 families with known mutations in the BRCA1/2 genes (associated with high risk of breast, ovarian, and other types of cancer) were identified by using the Colored Eco-Genetic Relationship Map (CEGRM). Hierarchical nonlinear models were fitted to characterize information gatherers, disseminators, and blockers.

RESULTS

Gatherers of information were more often female (P<.001), parents (P<.001), and emotional support providers (P<.001). Disseminators were more likely female first- and second-degree relatives (both P<.001), family members in the older or same generation as the participant (P<.001), those with a cancer history (P<.001), and providers of emotional (P<.001) or tangible support (P<.001). Blockers tended to be spouses or partners (P<.001) and male, first-degree relatives (P<.001).

CONCLUSIONS

Our results provide insight into which family members may, within a family-based intervention, effectively gather family risk information, disseminate information, and encourage discussions regarding shared family risk.

Associations of herbal and specialty supplements with lung and colorectal cancer risk in the VITamins and Lifestyle study

Millions of Americans use dietary supplements with little knowledge about their benefits or risks. We examined associations of various herbal/specialty supplements with lung and colorectal cancer risk. Men and women, 50 to 76 years, in the VITamins And Lifestyle cohort completed a 24-page baseline questionnaire that captured duration (years) and frequency (days per week) of use of commonly used herbal/specialty supplements. Dose was not assessed due to the lack of accurate potency information. Supplement exposure was categorized as "no use" or "any use" over the previous 10 years. Hazard ratios (HR) were estimated by multivariate Cox regression models. Incident lung (n = 665) and colorectal cancers (n = 428) were obtained from the Surveillance, Epidemiology, and End Results cancer registry. Any use of glucosamine and chondroitin, which have anti-inflammatory properties, over the previous 10 years, was associated with significantly lower lung cancer risk: HR 0.74 [95% confidence interval (95% CI), 0.58-0.94] and HR 0.72 (95% CI, 0.54-0.96) and colorectal cancer risk: HR 0.73 (95% CI, 0.54-0.98) and HR 0.65 (95% CI, 0.45-0.93), respectively. There were also statistically significantly inverse associations of fish oil: HR 0.65 (95% CI, 0.42-0.99), methylsulfonylmethane: HR 0.46 (95% CI, 0.23-0.93), and St. John's wort: HR 0.35 (95% CI, 0.14-0.85) with colorectal cancer risk. In contrast, garlic pills were associated with a statistically significant 35% elevated colorectal cancer risk. These results suggest that some herbal/specialty supplements may be associated with lung and colorectal cancer risk; however, these products should be used with caution. Additional studies examining the effects of herbal/specialty supplements on risk for cancer and other diseases are needed.

The effects of beta-glucan on human immune and cancer cells

Non-prescriptional use of medicinal herbs among cancer patients is common around the world. The alleged anti-cancer effects of most herbal extracts are mainly based on studies derived from in vitro or in vivo animal experiments. The current information suggests that these herbal extracts exert their biological effect either through cytotoxic or immunomodulatory mechanisms. One of the active compounds responsible for the immune effects of herbal products is in the form of complex polysaccharides known as beta-glucans. beta-glucans are ubiquitously found in both bacterial or fungal cell walls and have been implicated in the initiation of anti-microbial immune response. Based on in vitro studies, beta-glucans act on several immune receptors including Dectin-1, complement receptor (CR3) and TLR-2/6 and trigger a group of immune cells including macrophages, neutrophils, monocytes, natural killer cells and dendritic cells. As a consequence, both innate and adaptive response can be modulated by beta-glucans and they can also enhance opsonic and non-opsonic phagocytosis. In animal studies, after oral administration, the specific backbone 1-->3 linear beta-glycosidic chain of beta-glucans cannot be digested. Most beta-glucans enter the proximal small intestine and some are captured by the macrophages. They are internalized and fragmented within the cells, then transported by the macrophages to the marrow and endothelial reticular system. The small beta-glucans fragments are eventually released by the macrophages and taken up by other immune cells leading to various immune responses. However, beta-glucans of different sizes and branching patterns may have significantly variable immune potency. Careful selection of appropriate beta-glucans is essential if we wish to investigate the effects of beta-glucans clinically. So far, no good quality clinical trial data is available on assessing the effectiveness of purified beta-glucans among cancer patients. Future effort should direct at performing well-designed clinical trials to verify the actual clinical efficacy of beta-glucans or beta-glucans containing compounds.