Diet and breast cancer

Dietary intake and breast density in high-risk women: a cross-sectional study

Background

Women with a family history of breast cancer may be at higher risk for breast cancer, but few previous studies evaluating diet and breast cancer have focused on such women. The objective of the present study was to determine whether diet, a modifiable risk factor, is related to breast density among women at high genetic risk for breast cancer.

Methods

Women with at least one first-degree or second-degree relative with breast cancer or ovarian cancer participating in the Fox Chase Cancer Center Family Risk Assessment Program completed health history and food frequency questionnaires and received standard screening mammograms. Cranial–caudal mammographic images were classified into the four Breast Imaging Reporting and Data System categories ranging from 'entirely fatty' to 'extremely dense'. Logistic regression analysis using proportional odds models for polychotomous outcomes provided estimates of odds ratios for having a higher category versus a lower category of breast density.

Results

Among 157 high-risk women, breast density was inversely associated with vitamin D intake (odds ratio for third tertile versus first tertile, 0.5; 95% confidence interval, 0.2–1.0). In contrast, intakes above the median level for protein (odds ratio, 3.0; 95% confidence interval, 1.3–6.9) and above the median level for animal protein (odds ratio, 4.3; 95% confidence interval, 1.8–10.3) were associated with higher breast density, but only among women whose family history did not reflect a known familial cancer syndrome or a breast cancer predisposition gene.

Conclusion

For women with a strong family history that was not associated with known cancer syndromes, dietary factors may be associated with breast density, a strong predictor of breast cancer risk. Since women with strong family history are often very motivated to change their lifestyle habits, further studies are needed to confirm whether changes in diet will change the breast density and the subsequent onset of breast cancer in these women.

Consumption of commercial whole and non-fat milk increases the incidence of 7,12-dimethylbenz(a)anthracene-induced mammary tumors in rats

BACKGROUND

Breast cancer has become the most common cancer among women worldwide. Although the consumptions of milk and dairy products were considered to be a risk factor for breast cancer in some epidemiological studies, the results were inconsistent.

METHODS

In the present study, female Sprague-Dawley rats received a single oral dose of 5mg 7,12-dimethylbenz(a)anthracene (DMBA). One week later, the animals were divided into four groups: whole milk (WM), artificial whole milk (A-WM), non-fat milk (NFM) or artificial non-fat milk (A-NFM) mixed with commercial powder chow. Rats were palpated weekly to monitor tumor development. At week 20 after DMBA administration, rats were decapitated and the volume and weight of mammary tumor were recorded.

RESULTS

Tumor incidence, the cumulative number of tumors and the sums of tumor volume were higher in the WM and NFM groups than in the A-WM and A-NFM groups both at palpation and at autopsy.

CONCLUSION

Combining our previous studies, we found the consumption of milk promoted the development of DMBA-induced mammary tumors in rats independent of the fat level.

Comparisons of food intake between breast cancer patients and controls in Korean women

The purpose of this study was to compare food intakes between Korean breast cancer patients and a healthy control group. We compared the intake of nutrients of 117 food items between Korean breast cancer patients (n=97) and age matched healthy controls (n=97). Nutrient intake was estimated using a quantitative food frequency questionnaire. The mean caloric intake of breast cancer patients and healthy controls was not significantly different. Breast cancer patients consumed significantly less fat and antioxidant nutrients such as vitamin A, retinol, beta-carotene, vitamin C and vitamin E when compared to the control subjects. Among the food items, the intake of eggs (p<0.01), legumes (p<0.05), vegetables (p<0.05), seasonings (p<0.001), and oils and fats (p<0.01) in breast cancer patients was significantly lower than that in the controls. These results suggest that Korean breast cancer patients consumed less amount of soy and vegetables, which are rich source of antioxidant nutrients and phytosterols. Thus, dietary guidance to increase intake of these foods may be beneficial in the prevention of breast cancer.

Relation between insulin resistance and breast cancer among Chilean women

PURPOSE

In Chile, diabetes and breast cancer are important public health problems. The association between insulin resistance and breast cancer, however, remains largely unexplored.

METHODS

We conducted a case-control study to assess the relationship of insulin resistance (IR) and breast cancer in Chilean premenopausal and postmenopausal women. We compared 170 women, 33 to 86 years old, with incident breast cancer and 170 normal mammography controls, matched by 5-year age interval. Plasmatic insulin and glucose were measured and IR was calculated by the homeostasis model assessment method. Anthropometric measurements and sociodemographic and behavioral data were also collected. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by multivariable conditional logistic regression.

RESULTS

IR was independently associated with breast cancer in postmenopausal women (OR = 2.70, 95%CI = 1.10-6.63), but not in premenopausal women (OR = 0.84, 95%CI = 0.20-3.52). Obesity was not associated with breast cancer at any age (OR = 0.68, 95%CI = 0.39-1.20).

CONCLUSION

In this sample, IR increased the risk of breast cancer among postmenopausal women.

Alcohol intake and breast cancer risk among young women

INTRODUCTION

Alcohol intake has been consistently associated with breast cancer risk, but the importance of timing of intake and the impact of beverage type are unclear.

METHODS

We evaluated whether early, lifetime or recent alcohol intake was associated with breast cancer risk, and whether risk varied by type of alcoholic drinks in 1,728 newly diagnosed population-based breast cancer patients and 435 control subjects aged 20-49 years. We used multivariable logistic regression models to estimate odds ratios (OR) and 95% confidence intervals (CI) as measures of the relative risk of breast cancer associated with intake of alcoholic drinks.

RESULTS

Intake of alcoholic drinks during the recent five year period before the breast cancer diagnosis was associated with increased breast cancer risk (P (trend) = 0.04). Intake of two or more alcoholic drinks per day during this five year period was associated with an 82% increase in breast cancer risk relative to never drinkers (OR = 1.82, 95% CI = 1.01-3.28). No risk increase was observed for alcohol intake at ages 15-20 years or for lifetime alcohol intake. Risk did not vary by type of alcohol consumed.

CONCLUSIONS

Our results suggest that recent alcohol consumption may be associated with increased breast cancer risk in young women.

Intake of fruits, and vegetables in relation to breast cancer risk by hormone receptor status

SUMMARY

The inconsistent associations between fruit and vegetable intake and breast cancer risk may be due to heterogeneity of associations by estrogen (ER) and progesterone receptor (PR) status of the tumors. We evaluated this hypothesis in a large (2,386 cases and 2,503 controls) population-based case-control study in Poland, conducted between 2000 and 2003. We observed significant associations between reduced overall risk of breast cancer and increasing levels of total fruit intake (odds ratio (OR) for highest versus lowest quartile = 0.76, 95%CI = 0.63-0.91; p-trend = 0.01), but not for total vegetable intake (1.13 (0.93-1.37), p-trend = 0.25), after controlling for age, energy intake and known risk factors for breast cancer. The inverse association with total fruit intake was stronger for risk of ER+ (0.69 (0.54-0.88), p-trend = 0.01) than ER- tumors (0.89 (0.67-1.19), p-trend = 0.57) (p-heterogeneity = 0.02). In conclusion, this study suggests that fruit intake might have differential associations for breast tumor subtypes defined by ER status.

Dietary fat, fiber, vegetable, and micronutrients are associated with overall survival in postmenopausal women diagnosed with breast cancer

Relatively few studies have assessed the relationship between dietary intakes and survival after breast cancer diagnosis. We investigated the influence of diet, including dietary fat (percentage energy), fiber, vegetable, and fruit intakes, and micronutrients (folate, carotenoids, and vitamin C) on overall survival in women diagnosed with breast cancer. Subjects were postmenopausal women diagnosed with breast cancer (N = 516) between 1994 and 1995 with a mean survival time of 80 mo (SD: 18). Subjects completed a food frequency questionnaire for the year prior to diagnosis. Cox proportional hazards models were used to measure the relationship between dietary intakes and death due to any cause after breast cancer diagnosis. In the multivariate analysis, we found that the hazard ratio [HR and 95% confidence interval (CI)] of dying in the highest tertile compared to the lowest tertile of total fat, fiber, vegetable, and fruit was 3.12 (95% CI = 1.79-5.44), 0.48 (95% CI = 0.27-0.86), 0.57 (95% CI = 0.35-0.94), and 0.63 (95% CI = 0.38-1.05), respectively (P <or= 0.05 for trend, except for fruit intake). Other nutrients including folate, vitamin C, and carotenoid intakes were also significantly associated with reduced mortality (P <or= 0.05 for trend). These results suggest that in postmenopausal women diagnosed with breast cancer, reduced dietary fat and increased fiber, vegetable, fruit, and other nutrient intakes associated with a plant-based, high-fiber diet improves overall survival after breast cancer diagnosis.

Associations among maternal soy intake, isoflavone levels in urine and blood samples, and maternal and umbilical hormone concentrations (Japan)

OBJECTIVES

In utero exposure to high levels of endogenous estrogens has been hypothesized to increase breast cancer risk in later life. A high intake of soy has been suggested to protect against breast cancer. We examined the hypothesis that maternal soy intake may be inversely associated with pregnancy hormone levels.

METHODS

The concentrations of hormones (estradiol, estriol, and testosterone) and isoflavones (genistein, deidzein, and equol) were measured in the maternal urine and serum, and umbilical cord blood of 194 women during pregnancy and at delivery. Soy intake during pregnancy was assessed by 5-day diet records at approximately the 29th week of pregnancy.

RESULTS

High correlations were observed for isoflavone levels between maternal samples and umbilical cord blood, indicating that isoflavone can be transferred from the maternal to the fetal compartment. None of the hormones measured in umbilical cord blood was significantly associated with any of the isoflavones measured. There were a few significant associations between maternal hormone levels and isoflavone measures during pregnancy, but their patterns of associations varied by gestational week and differed depending on whether isoflavone exposure was measured by diet records, urine or serum.

CONCLUSION

Our data contain no strong evidence showing that soy intake affects hormone levels during pregnancy.

Dietary fibre and risk of breast cancer in the UK Women's Cohort Study

BACKGROUND

Reports of relationships between dietary fibre intake and breast cancer have been inconsistent. Previous cohort studies have been limited by a narrow range of intakes.

METHODS

Women who developed invasive breast cancer, 350 post-menopausally and 257 pre-menopausally, during 240,959 person-years of follow-up in the UK Women's Cohort Study (UKWCS) were studied. This cohort has 35,792 subjects with a wide range of exposure to dietary fibre with intakes of total fibre in the lowest quintile of <20 g/day up to >30 g/day in the top quintile. Fibre and breast cancer relationships were explored using Cox regression modelling adjusted for measurement error. Effects of fibre, adjusting for confounders were examined for pre- and post-menopausal women separately.

RESULTS

In pre-menopausal, but not post-menopausal women a statistically significant inverse relationship was found between total fibre intake and risk of breast cancer (P for trend = 0.01). The top quintile of fibre intake was associated with a hazard ratio of 0.48 [95% confidence interval (CI) 0.24-0.96] compared with the lowest quintile. Pre-menopausally, fibre from cereals was inversely associated with risk of breast cancer (P for trend = 0.05) and fibre from fruit had a borderline inverse relationship (P for trend = 0.09). A further model including dietary folate strengthened the significance of the inverse relationship between total fibre and pre-menopausal breast cancer.

CONCLUSIONS

These findings suggest that in pre-menopausal women, total fibre is protective against breast cancer; in particular, fibre from cereals and possibly fruit.

Breast cancer risk factors and second primary malignancies among women with breast cancer

PURPOSE

To examine the association between breast cancer risk factors and second primary cancers (independent diagnoses occurring at least 12 months after the initial breast cancer diagnosis) among breast cancer survivors.

METHODS

In this population-based study, cancer outcomes among breast cancer survivors first diagnosed during 1987-2000 were investigated. Invasive breast cancer cases were identified from the statewide tumor registry and interviewed regarding their pre-diagnosis risk factors, including reproductive and lifestyle characteristics, approximately 1 year after diagnosis. Data on second primary cancers (not recurrences) and deaths were obtained by linkage with tumor registry reports and death certificates through December 31, 2002. Hazard ratios (HR) were estimated using proportional hazards regression stratified by age and adjusted for stage and other factors.

RESULTS

Among the 10,953 breast cancer cases, 10.8% experienced a second cancer diagnosis within an average of 7 years (including 488 breast, 132 colorectal, 113 endometrial, and 36 ovarian cancers). Risk of a second primary breast cancer increased according to low parity (P = 0.002), older age at menopause (P = 0.08), greater body mass index (P = 0.003) and adult weight gain (P = 0.02), and a family history of breast cancer-particularly among women with 2 or more first-degree affected relatives (HR = 1.8, 95% CI: 1.1-2.9). Reduced risk of colorectal cancer after breast cancer was observed in relation to older ages at menarche (P = 0.05), younger age at menopause (P = 0.04), postmenopausal hormone use (HR = 0.4, 95% CI: 0.3-0.7), normal body mass index (P = 0.07), and infrequent alcohol consumption (P = 0.01). Second endometrial cancer risk was associated with increasing body mass index (P < 0.01) and adult weight gain (P = 0.03). Risk of second ovarian cancer appeared related to recent alcohol intake and family history of breast cancer. Women who reported consuming any alcohol appeared to have a 55% reduction in ovarian cancer risk (95% CI: 0.2-1.0) compared to non-drinkers, while having 2 or more first-degree relatives with breast cancer was associated with an increased risk of ovarian cancer (HR = 4.3, 95% CI: 1.3-14.6).

CONCLUSION

This study suggests that family history of breast cancer as well as potentially modifiable characteristics including body weight, alcohol intake, and postmenopausal hormone use may be associated with risk of a second cancer diagnosis among breast cancer cases.

Associations of menstrual cycle length with intake of soy, fat, and dietary fiber in Japanese women

A decreased risk of breast cancer has been reported among women who have longer menstrual cycles or anovulatory cycles. The present study examined the relationships between intake of fat, soy, and dietary fiber and length of menstrual cycle among 341 Japanese women aged 18 to 29 yr old at two colleges and three nursing schools. Intake of nutrients and foods including fats, dietary fiber, and soy products was estimated through the use of a validated semi-quantitative food frequency questionnaire. The mean cycle length was determined for each women based on a prospective record of menstruation. Polyunsaturated fat intake was significantly inversely associated with cycle length; the means of cycle length were 33.2 and 31.0 days for the lowest and the highest quintiles of intake, respectively, after controlling for covariates (trend = 0.03). The odds ratio of a long cycle (> 35 days) for the highest vs. lowest quintile of dietary fiber intake was 2.12 (95% confidence interval 1.00-4.47), although the trend was not statistically significant. The data suggest that polyunsaturated fat and dietary fiber intake are associated with the parameters of menstrual cycle length, but further studies are required to better characterize these associations.

Differences in breast cancer mortality worldwide: unsolved problems

Breast cancer mortality remains a major cause of female mortality. Between 1970 and 2000 both important increases and decreases in breast cancer mortality rates occurred. Large differences in breast cancer mortality exist among countries worldwide. Contradictory findings concerning the role of lifestyle, especially nutrition, remain to be explained. Possible explanations for the observed mortality differences will be explored. Breast cancer mortality rates have been correlated with other causes of mortality; both cancer and noncancer, using data obtained from 47 countries worldwide (World Health Organization). They have also been correlated with dietary data, especially concerning fat (animal and vegetal) intake (Food and Agricultural Organization). Highly significant correlations existed between breast cancer mortality and mortality from other cancers (e.g. colon, stomach) obtained from both sexes. These correlations have been confirmed over a period of more than 40 years. Highly significant positive correlations also existed with the intake of animal (saturated) fat, covering a period of 30 years. In multivariate regression, only the relationship with the colon, prostate cancer and total energy intake remained significant. Ecological data point to nutritional factors, especially animal fat, as major promoters of breast cancer mortality worldwide. This contrasts with the results of most cohort studies. These contradictory results and the relationship between breast cancer mortality and other causes of mortality remain to be explained. More refined and standardized dietary data are necessary.

Increases in Plasma Carotenoid Concentrations in Response to a Major Dietary Change in the Women's Healthy Eating and Living Study

BACKGROUND

Cohort studies suggest that higher circulating carotenoid concentrations through food sources may reduce breast cancer events. Other intervention studies have not achieved the level of change in circulating carotenoids required to properly test this hypothesis.

METHODS

In a randomized trial of 2,922 breast cancer survivors, we examined blood and self-reported diet at baseline and 1 year. Intensive telephone counseling encouraged a plant-based diet in the intervention group. Diet was measured via 24-hour recalls, and a panel of plasma carotenoid concentrations was assessed at both time points.

RESULTS

The study intervention was associated with a 51% increase in total carotenoid concentration, from 2.272 +/- 1.294 to 3.440 +/- 2.320 micromol/L, achieved mainly by marked increases in targeted carotenoids: alpha-carotene, beta-carotene, and lutein. For each of these targeted carotenoids, the proportion of the intervention sample remaining below the cutpoint for the lowest baseline quartile decreased by one third to one half. After 1 year of study, half of the intervention group was in the highest baseline quartile. No change in distribution was observed in comparison group. Intervention participants achieved this change by both dietary pattern and vegetable juice consumption. Participants who chose to change dietary pattern without consuming significant quantities of vegetable juice achieved 75% of the level of change observed in other intervention participants.

CONCLUSIONS

Innovative telephone counseling intervention and dietary targets in the Women's Healthy Eating and Living study were associated with the level of change in circulating carotenoid concentration necessary to test the diet and breast cancer hypothesis suggested by cohort studies.

The inhibition of lung colonization of B16-F10 melanoma cells in EFA-deficient animals is related to enhanced apoptosis and reduced angiogenesis

Previous studies conducted in our laboratory showed that the reproduction of spontaneous and experimental metastases was reduced in host animals deprived of essential fatty acids (EFA). In the present study, we have explored the possibility whether apoptosis, proliferation, and angiogenesis might be involved in the antimetastatic effect of EFA deficiency. To this aim, in pulmonary colonies developed from B16-F10 cells in EFA-deficient animals or in animals fed a 5% corn oil diet, we performed an immunohistochemical analysis of bcl-2/bax proteins, PCNA, and VEGF and von Willebrand Factor (vWF), typical markers of apoptosis, proliferation, and angiogenesis, respectively. Apoptosis was also evaluated by detecting DNA fragments in metastatic cells. We found that the reduction of pulmonary colonies grown in EFA-deficient animals was associated with a high expression of apoptotic activity as revealed by the presence of apoptotic nuclei and a high immunoreactivity for bax. Cell proliferation seemed not to be influenced by EFA deficiency in view of the observation that PCNA was highly expressed in pulmonary colonies of control as well as EFA-deficient animals. Pulmonary colonies developed in EFA- deficient animals showed a lower expression of VEGF and a decreased microvessel density, indicating that a reduced angiogenesis contributes to the antimetastatic effects of EFA deficiency. Our analysis of the results invokes the possibility that a relationship between angiogenesis and apoptosis may account for the diminution of the development of experimental metastases in the lungs of EFA-deficient animals.

Role of Lipid Peroxidation in the Epidemiology and Prevention of Breast Cancer

We have recently proposed a common mechanistic pathway by which obesity and hypertension lead to increased renal cell cancer risk. Our hypothesis posits lipid peroxidation, which is a principal mechanism in rodent renal carcinogenesis, as an intermediate step that leads to a final common pathway shared by numerous observed risks (including obesity, hypertension, smoking, oophorectomy/hysterectomy, parity, preeclampsia, diabetes, and analgesics) or protective factors (including oral contraceptive use and alcohol) for renal cell cancer [Cancer Causes Control 2002;13:287-93]. During this exercise, we have noticed how certain risk factors for renal cell carcinoma are protective for breast cancer and how certain protective factors for renal cell carcinoma increase risk for breast cancer. Parity and oophorectomy, for example, are positively associated with renal cell carcinoma but are negatively associated with breast cancer. Similarly, obesity and hypertension are positively associated with renal cell carcinoma, but obesity is negatively associated with breast cancer in premenopausal women and hypertension during pregnancy is negatively associated with breast cancer. Furthermore, alcohol intake, negatively associated with renal cell carcinoma, is also positively associated with breast cancer. We propose here the possibility that lipid peroxidation may represent a protective mechanism in breast cancer. Although this runs counter to the conventional view that lipid peroxidation is a process that is harmful and carcinogenic, we present here the chemical and biological rationale, based on epidemiologic and biochemical data, which may deserve further consideration and investigation.

Associations between breast cancer risk and the catalase genotype, fruit and vegetable consumption, and supplement use

Observed weak or null associations between fruit and vegetable intake and breast cancer risk could be due to heterogeneity in endogenous antioxidant capabilities. The authors evaluated potential relations between a functional polymorphism in catalase, an antioxidant enzyme, and breast cancer risk, particularly in relation to fruit and vegetable intake and supplement use. Women (1,008 cases and 1,056 controls) in the Long Island Breast Cancer Study Project (1996-1997) were interviewed, completed a food frequency questionnaire, and provided blood for genotyping. The high-activity catalase CC genotype was associated with an overall 17% reduction in risk of breast cancer compared with having at least one variant T allele (odds ratio = 0.83, 95% confidence interval: 0.69, 1.00). Vegetable and, particularly, fruit consumption contributed to the decreased risk associated with the catalase CC genotype. Associations were more pronounced among women who did not use vitamin supplements, with a significant multiplicative interaction (p(interaction) = 0.02) for the CC genotype and high fruit intake (odds ratio = 0.59, 95% confidence interval: 0.38, 0.89), and there was no association among supplement users. These results indicate the importance of diet, rather than supplement use, in concert with endogenous antioxidant capabilities, in the reduction of breast cancer risk. CC genotypes were prevalent in approximately 64% of controls; thus, the preventive potential for fruit consumption has widespread implications.

Liposome-encapsulated curcumin: in vitro and in vivo effects on proliferation, apoptosis, signaling, and angiogenesis

BACKGROUND

Because a role for nuclear factor-kappaB (NF-kappaB) has been implicated in the pathogenesis of pancreatic carcinoma, this transcription factor is a potential target for the treatment of this devastating disease. Curcumin (diferuloylmethane) is a phytochemical with potent NF-kappaB-inhibitory activity. It is pharmacologically safe, but its bioavailability is poor after oral administration.

METHODS

The authors encapsulated curcumin in a liposomal delivery system that would allow intravenous administration. They studied the in vitro and in vivo effects of this compound on proliferation, apoptosis, signaling, and angiogenesis using human pancreatic carcinoma cells. NF-kappaB was constitutively active in all human pancreatic carcinoma cell lines evaluated and liposomal curcumin consistently suppressed NF-kappaB binding (electrophoretic mobility gel shift assay) and decreased the expression of NF-kappaB-regulated gene products, including cyclooxygenase-2 (immunoblots) and interleukin-8 (enzyme-linked immunoassay), both of which have been implicated in tumor growth/invasiveness. These in vitro changes were associated with concentration and time-dependent antiproliferative activity (3-[4,5-dimethylthiazol-2-yl]2,5-diphenyltetrazolium bromide assay [MTT assay]) and proapoptotic effects (annexin V/propidium iodide staining [fluorescence-activated cell sorting] and polyadenosine-5'-diphosphate-ribose-polymerase cleavage).

RESULTS

The activity of liposomal curcumin was equal to or better than that of free curcumin at equimolar concentrations. In vivo, curcumin suppressed pancreatic carcinoma growth in murine xenograft models and inhibited tumor angiogenesis.

CONCLUSIONS

Liposomal curcumin down-regulated the NF-kappaB machinery, suppressed growth, and induced apoptosis of human pancreatic cells in vitro. Antitumor and antiangiogenesis effects were observed in vivo. The experiments in the current study provide a biologic rationale for treatment of patients suffering from pancreatic carcinoma with this nontoxic phytochemical encapsulated in liposomes for systemic delivery.

Long-term weight change and breast cancer risk: the European prospective investigation into cancer and nutrition (EPIC)

We examined prospectively the association between weight change during adulthood and breast cancer risk, using data on 1358 incident cases that developed during 5.8 years of follow-up among 40 429 premenopausal and 57 923 postmenopausal women from six European countries, taking part in the European prospective investigation into cancer and nutrition study. Multivariate Cox regression models were used to calculate hazard ratios according to weight change (kg), defined as the weight difference between age at enrolment and age 20 adjusted for other risk factors. Changes in weight were not associated with premenopausal breast cancer risk. In postmenopausal women, weight gain was positively associated with breast cancer risk only among noncurrent hormone replacement therapy (HRT) users (P-trend ⩽0.0002). Compared to women with a stable weight (±2 kg), the relative risk for women who gained 15–20 kg was 1.50 (95% confidence interval (CI) 1.06–2.13). The pooled RR per weight gain increment of 5 kg was 1.08 (95% CI 1.04–1.12). Weight gain was not associated with breast cancer risk in current HRT users, although, overall, these women experienced a much higher risk of breast cancer compared with nonusers. Our findings suggest that large adult weight gain was a significant predictor of breast cancer in postmenopausal women not taking exogenous hormones.

Dietary intakes of fat and fatty acids and risk of breast cancer: a prospective study in Japan

To examine the possible association of dietary fat and fatty acids with breast cancer risk in a population with a low total fat intake and a high consumption of fish, we analyzed data from the Japan Collaborative Cohort (JACC) Study. From 1988 to 1990, 26 291 women aged 40-79 years completed a questionnaire on dietary and other factors. Intakes of fat or fatty acids were estimated by using a food frequency questionnaire. Rate ratios (RR) were computed by fitting proportional hazards models. During the mean follow-up of 7.6 years, 129 breast cancer cases were documented. We found no clear association of total fat intake with breast cancer risk; the multivariate-adjusted RR across quartiles were 1.00, 1.29, 0.95, and 0.80 (95% confidence interval [CI] 0.46-1.38). A significant decrease in the risk was detected for the highest quartile of intake compared with the lowest for fish fat and long-chain n-3 fatty acids; the RR were 0.56 (95% CI 0.33-0.94) and 0.50 (0.30-0.85), respectively. A decreasing trend in risk was also suggested with an increasing intake of saturated fatty acids (trend P = 0.066). Among postmenopausal women at baseline, the highest quartile of vegetable fat intake was associated with a 2.08-fold increase in risk (95% CI 1.05-4.13). This prospective study did not support any increase in the risk of breast cancer associated with total or saturated fat intake, but it suggested the protective effects of the long-chain n-3 fatty acids that are abundant in fish.

The possible role of female sex hormones in milk from pregnant cows in the development of breast, ovarian and corpus uteri cancers

The continued increase in incidence of some hormone-related cancers worldwide is of great concern. Although estrogen-like substances in the environment were blamed for this increase, the possible role of endogenous estrogens from food has not been widely discussed. We are particularly concerned about cows' milk, which contains a considerable quantity of estrogens. When we name cows' milk as one of the important routes of human exposure to estrogens, the general response of Western people is that "man has been drinking cows' milk for around 2000 years without apparent harm." However, the milk that we are now consuming is quite different from that consumed 100 years ago. Unlike their pasture-fed counterparts of 100 years ago, modern dairy cows are usually pregnant and continue to lactate during the latter half of pregnancy, when the concentration of estrogens in blood, and hence in milk, increases. The correlation of incidence and mortality rates with environmental variables in worldwide countries provides useful clues to the etiology of cancer. In this study, we correlated incidence rates for breast, ovarian, and corpus uteri cancers (1993-97 from Cancer Incidence in Five Continents) with food intake (1961-97 from FAOSTAT) in 40 countries. Meat was most closely correlated with the breast cancer incidence (r=0.827), followed by milk (0.817) and cheese (0.751). Stepwise multiple-regression analysis (SMRA) identified meat as the factor contributing most greatly to the incidence of breast cancer ([R]=0.862). Milk was most closely correlated with the incidence of ovarian cancer (r=0.779), followed by animal fats (0.717) and cheese (0.697). SMRA revealed that milk plus cheese make the greatest contribution to the incidence of ovarian cancer ([R]=0.767). Milk was most closely correlated with corpus uteri cancer (r=0.814), followed by cheese (0.787). SMRA revealed that milk plus cheese make the most significant contribution to the incidence of corpus uteri cancer ([R]=0.861). In conclusion, increased consumption of animal-derived food may have adverse effects on the development of hormone-dependent cancers. Among dietary risk factors, we are most concerned with milk and dairy products, because the milk we drink today is produced from pregnant cows, in which estrogen and progesterone levels are markedly elevated.

Dietary fat intake and early mortality patterns--data from The Malmö Diet and Cancer Study

OBJECTIVES

Most current dietary guidelines encourage limiting relative fat intake to <30% of total daily energy, with saturated and trans fatty acids contributing no more than 10%. We examined whether total fat intake, saturated fat, monounsaturated, or polyunsaturated fat intake are independent risk factors for prospective all-cause, cardiovascular and cancer mortality.

DESIGN

Population-based, prospective cohort study.

SETTING AND SUBJECTS

The Malmö Diet and Cancer Study was set in the city of Malmö, southern Sweden. A total of 28,098 middle-aged individuals participated in the study 1991-1996.

MAIN OUTCOME MEASURES

Subjects were categorized by quartiles of relative fat intake, with the first quartile used as a reference point in estimating multivariate relative risks (RR; 95% CI, Cox's regression model). Adjustments were made for confounding by age and various lifestyle factors.

RESULTS

Women in the fourth quartile of total fat intake had a significantly higher RR of cancer mortality (RR 1.46; CI 1.04-2.04). A significant downwards trend was observed for cardiovascular mortality amongst men from the first to the fourth quartile (P=0.028). No deteriorating effects of high saturated fat intake were observed for either sex for any cause of death. Beneficial effects of a relatively high intake of unsaturated fats were not uniform.

CONCLUSIONS

With the exception of cancer mortality for women, individuals receiving more than 30% of their total daily energy from fat and more than 10% from saturated fat, did not have increased mortality. Current dietary guidelines concerning fat intake are thus generally not supported by our observational results.

Dietary patterns and the risk of postmenopausal breast cancer

The association between individual foods and breast cancer has been inconsistent. Therefore, we examined the association between diet and risk of postmenopausal breast cancer by the alternative approach of dietary patterns. Dietary patterns were identified with factor analysis from food consumption data collected from a food frequency questionnaire in 1984. Relative risks were computed using proportional hazard models and adjusted for known risk factors for breast cancer. Between 1984 and 2000, we ascertained 3,026 incident cases of postmenopausal breast cancer. We identified 2 major dietary patterns. The prudent pattern is characterized by higher intake of fruits, vegetables, whole grains, low-fat dairy products, fish and poultry, while the Western pattern is characterized by higher intake of red and processed meats, refined grains, sweets and desserts and high-fat dairy products. Neither of the patterns was associated with overall risk of postmenopausal breast cancer. However, a positive association between the Western pattern score was observed among smokers at baseline (relative risk = 1.44, comparing top to bottom quintiles; 95% CI = 1.02-2.03; p for trend = 0.03). An inverse association was observed between the prudent pattern and estrogen receptor-negative cancer (relative risk = 0.62; 95% CI = 0.45-0.88; p for trend = 0.006). Among the major food groups, higher consumptions of fruits (relative risk for 1 serving/day increase = 0.88; 95% CI = 0.80-0.97; p = 0.009) and vegetables (relative risk = 0.94; 95% CI = 0.88-0.99; p = 0.03) were significantly associated with decreased risk for ER(-) breast cancer. In conclusion, we did not observe an overall association between the prudent or Western pattern and overall breast cancer risk. However, a Western-type diet may elevate risk of breast cancer among smokers, and a prudent diet may protect against estrogen receptive-negative tumors.

Gene-nutrient interactions in cancer etiology

Relationships between dietary components and cancer risk are often unclear, and the results from epidemiologic studies are inconsistent. While some inconsistencies could be due to study design issues, we propose that genetic heterogeneity of study populations could mask associations. In this report, we review the literature regarding meat consumption and risk of colon, breast, and prostate cancers, particularly in relation to phenotypes and genotypes for enzymes that metabolize food-borne promutagens. The role of consumption of fruits and vegetables, as well as the role of genetic variants in oxidative stress genes, in the risk of breast cancer are also discussed.

Behaviour partly explains educational differences in cancer incidence in the south-eastern Netherlands: the longitudinal GLOBE study

Cancer morbidity and mortality vary among socio-economic groups. We investigated whether educational differences in behaviour could explain the variation in cancer incidence. In 1991, a postal questionnaire on socio-economic status, exposure variables, health and health-related behaviour was filled out by 18,973 participants (response rate 70.1%) of the longitudinal GLOBE study. Participants were followed and linked with the regional population-based Eindhoven Cancer Registry. Between 1991 and 1998 a total of 760 new tumours were found. The risk of cancer (all sites combined) was higher in the three quartiles of lower educational level compared with the highest educational level, odds ratios (ORs) varying from 1.25, 1.34, 1.27 to 1.00 from the lowest to the highest category, respectively (P=0.14). The relative risk (RR) for lung cancer for low versus high education was 2.7 [95% confidence interval (CI) 1.3-5.3]; adjustment for smoking, alcohol intake and physical activity decreased the risk to 1.6 (95% CI 0.8-3.3). Smoking alone explained 39% of the association, when alcohol intake and physical exercise were added to the model 61% of the effect was explained. In conclusion, a lower education is associated with increased cancer risks, which can be explained partly by behavioural factors.

Nuclear factor-kappaB and IkappaB kinase are constitutively active in human pancreatic cells, and their down-regulation by curcumin (diferuloylmethane) is associated with the suppression of proliferation and the induction of apoptosis

BACKGROUND

Pancreatic carcinoma is a lethal malignancy, with the best available therapeutic option-gemcitabine-yielding response rates of < 10%. Because nuclear factor-kappaB (NF-kappaB) has been determined to play a role in cell survival/proliferation in human pancreatic carcinoma, this transcription factor is a potential therapeutic target.

METHODS

The authors investigated the ability of curcumin (diferuloylmethane), an agent that is pharmacologically safe in humans, to modulate NF-kappaB activity.

RESULTS

NF-kappaB and IkappaB kinase (IKK) were constitutively active in all human pancreatic carcinoma cell lines examined, and curcumin consistently suppressed NF-kappaB binding (as assessed using an electrophoretic mobility gel-shift assay) and IKK activity. Curcumin decreased the expression of NF-kappaB-regulated gene products, including cyclooxygenase-2 (as assessed using immunoblot analysis), prostaglandin E2, and interleukin-8 (as assessed using an enzyme-linked immunoassay), all of which have been implicated in the growth and invasiveness of pancreatic carcinoma. These changes were associated with concentration- and time-dependent antiproliferative activity (as assessed using a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide [MTT] assay) and proapoptotic effects (as assessed via annexin V/propidium iodide staining [fluorescence-activated cell sorting, as well as with the induction of polyadenosine-5'-diphosphate-ribose polymerase cleavage).

CONCLUSIONS

Curcumin down-regulated NF-kappaB and growth control molecules induced by NF-kappaB in human pancreatic cells. These effects were accompanied by marked growth inhibition and apoptosis. Through these findings, the authors provided a biologic rationale for the treatment of patients with pancreatic carcinoma using this nontoxic phytochemical.

Nutritional fats and the risk of type 2 diabetes and cancer

Dietary factors are important predictors for the risk of diabetes type 2. Increased consumption of fibre-rich foods, fruits and vegetables as well as limited amounts of total and saturated fats are essential elements in the prevention of diabetes type 2. The association between these dietary factors and the appearance of diabetes was not only present in cohort studies but were also major elements in the dietary part of the two large diabetes prevention trials (Finnish Diabetes Prevention Study, Diabetes Prevention Program). There is also strong evidence for a relation between obesity and total fat intake and the incidence of certain types of cancers. There is a significant correlation between total fat intake and the risk of cancer; however, it is much weaker than that of the effect of red meat. Recommendations to decrease red meat intake, particularly processed meat, may decrease the risk of colorectal and prostate cancer and may have beneficial effects on breast cancer as well, although this evidence is less compelling. Overall, recommendations focused on controlling or reducing body weight by regular physical activity and avoidance of excessive energy intake from all sources, particularly from fat and saturated fats, by increasing consumption of fibre-rich carbohydrates, vegetables and fruits are effective in decreasing the risk for type 2 diabetes by more than 50% in high-risk individuals. Similar dietary patterns are likely to diminish the manifestation of certain forms of cancers. These conclusions are in agreement with current recommendations for cancer prevention as propagated by the American Cancer Society.

Long-chain (n-3) fatty acid intake and risk of cancers of the breast and the prostate: recent epidemiological studies, biological mechanisms, and directions for future research

The association between dietary (n-3) fatty acids and hormone-responsive cancers continues to attract considerable attention in epidemiological, clinical, and experimental studies. We previously reviewed the epidemiological literature on the association between hormone-responsive cancers and the long-chain fatty acids eicosapentaenoic acid and docosahexaenoic acid. We concluded that the compelling evidence from ecological studies, animal models, and mechanistic experiments in vitro was not supported clearly by the available epidemiological data. To various degrees, epidemiological studies published more recently attempted to address some of the methodological limitations plaguing earlier studies by using validated questionnaires, examining specific fatty acids and their interrelationships, and adjusting estimates for a wider range of potentially confounding factors than in previous studies. In this review, our aim was to update the previous review with the results of recent epidemiological studies and to discuss possible biological mechanisms and directions for future research.

Fruits, Vegetables, and Micronutrients in Relation to Breast Cancer Modified by Menopause and Hormone Receptor Status

Whether fruit, vegetable, and antioxidant micronutrient consumption is associated with a reduction in breast cancer incidence remains unresolved. To address this issue, we analyzed data from a large population-based case-control study, with consideration given to whether the associations varied with menopausal status or with clinical characteristics of the cases' disease. Study participants completed a modified Block food frequency questionnaire, which included assessment of the frequency and portion sizes of 13 fruits and fruit juices and 16 vegetables and the use of multiple and single vitamin supplements. Statistical analyses were done on 1,463 cases and 1,500 controls. Among postmenopausal women, reduced odds ratios [OR; 95% confidence intervals (95% CI)] were noted for the highest fifth, as compared with the lowest fifth, of intake of any vegetables [0.63 (0.46–0.86); P for trend &lt; 0.01] and leafy vegetables [0.66 (0.50–0.86); P for trend = 0.03] after controlling for age and energy intake. Adjusted ORs (95% CIs) were also decreased for postmenopausal breast cancer in relation to high intake of carotenoids, α-carotene, β-carotene, lutein, and particularly lycopene [0.66 (0.48–0.90); P for trend = 0.03]. Inverse associations for fruits and vegetables were stronger for postmenopausal women with estrogen receptor (ER)+ tumors (OR, 0.65; 95% CI, 0.51–0.82) than ER− tumors (OR, 0.92; 95% CI, 0.64–1.32), but results were less consistent for micronutrients. No similarly reduced associations were observed among premenopausal women. ORs did not appreciably differ by in situ or invasive breast cancer or by whether cases had begun chemotherapy. Our results support an inverse association for fruit and vegetable intake among postmenopausal but not premenopausal breast cancer, which may be more pronounced among women with ER+ tumors.

Body size and breast cancer risk: findings from the European Prospective Investigation into Cancer And Nutrition (EPIC)

The evidence for anthropometric factors influencing breast cancer risk is accumulating, but uncertainties remain concerning the role of fat distribution and potential effect modifiers. We used data from 73,542 premenopausal and 103,344 postmenopausal women from 9 European countries, taking part in the EPIC study. RRs from Cox regression models were calculated, using measured height, weight, BMI and waist and hip circumferences; categorized by cohort-wide quintiles; and expressed as continuous variables, adjusted for study center, age and other risk factors. During 4.7 years of follow-up, 1,879 incident invasive breast cancers were identified. In postmenopausal women, current HRT modified the body size-breast cancer association. Among nonusers, weight, BMI and hip circumference were positively associated with breast cancer risk (all ptrend < or = 0.002); obese women (BMI > 30) had a 31% excess risk compared to women with BMI < 25. Among HRT users, body measures were inversely but nonsignificantly associated with breast cancer. Excess breast cancer risk with HRT was particularly evident among lean women. Pooled RRs per height increment of 5 cm were 1.05 (95% CI 1.00-1.16) in premenopausal and 1.10 (95% CI 1.05-1.16) in postmenopausal women. Among premenopausal women, hip circumference was the only other measure significantly related to breast cancer (ptrend = 0.03), after accounting for BMI. In postmenopausal women not taking exogenous hormones, general obesity is a significant predictor of breast cancer, while abdominal fat assessed as waist-hip ratio or waist circumference was not related to excess risk when adjusted for BMI. Among premenopausal women, weight and BMI showed nonsignificant inverse associations with breast cancer.

Carbohydrates and the Risk of Breast Cancer among Mexican Women

Objective: High carbohydrate intake has been hypothesized to be a risk factor for breast cancer, possibly mediated by elevated levels of free insulin, estrogens, and insulin-like growth factor-1. Therefore, we conducted a population-based case-control study among a Mexican population characterized by relatively low fat and high carbohydrate intakes. Methods: Women ages 20 to 75 years, identified through six hospitals in Mexico City (n = 475), were interviewed to obtain data relating to diet (using a food frequency questionnaire) and breast cancer risk factors. Controls (n = 1,391) were selected from the Mexico City population using a national sampling frame. Results: Carbohydrate intake was positively associated with breast cancer risk. Compared with women in the lowest quartile of total carbohydrate intake, the relative risk of breast cancer for women in the highest quartile was 2.22 [95% confidence interval (95% CI) 1.63-3.04], adjusting for total energy and potential confounding variables (P for trend &lt; 0.0001). This association was present in premenopausal and postmenopausal women (for highest versus lowest quartile, odds ratio 2.31, 95% CI 1.36-3.91 in premenopausal women and odds ratio 2.22, 95% CI 1.49-3.30 in postmenopausal women). Among carbohydrate components, the strongest associations were observed for sucrose and fructose. No association was observed with total fat intake. Discussion: In this population, a high percentage of calories from carbohydrate, but not from fat, was associated with increased breast cancer risk. This relation deserves to be investigated further, particularly in populations highly susceptible to insulin resistance.

Health behavior change among women with recent familial diagnosis of breast cancer

BACKGROUND

Although first-degree female relatives (FDFR) of women with breast cancer are at increased risk for the disease, little is understood about how familial diagnosis impacts health behaviors and what personal factors predict such changes.

METHODS

Six hundred women, ages 18 and over with a FDFR recently diagnosed with breast cancer, were interviewed after the diagnosis and again in 6 months. Participants self-reported changes in physical activity, fruit and vegetable consumption, fat consumption, alcohol and tobacco use. The effect of baseline demographics, health status, perceptions of relative's disease severity, personal risk, control over the disease and the effect of lifestyle behaviors on risk was assessed in relation to behavior changes.

RESULTS

Forty-two percent reported improving one or more behaviors. Perception that the behavior was a risk factor for breast cancer was positively associated with change for all behaviors except smoking. Poor health status, obesity and perception of control over breast cancer were associated with improvements in physical activity, fruit and vegetable consumption and fat consumption.

CONCLUSIONS

Diagnosis of breast cancer in a first-degree relative can provide motivation to improve health behavior. Educational interventions highlighting the importance of these behaviors in reducing breast cancer risk and promoting health in general may be effective in this population.

Consumption of dairy products and the risk of breast cancer: a review of the literature

Differences in eating patterns and breast cancer rates across countries suggest that several dietary components, including dairy products, could affect breast cancer risk. However, dairy products are a diverse food group in terms of the factors that could potentially influence risk. Some dairy products, such as whole milk and many types of cheese, have a relatively high saturated fat content, which may increase risk. Moreover, milk products may contain contaminants such as pesticides, which have carcinogenic potential, and growth factors such as insulin-like growth factor I, which have been shown to promote breast cancer cell growth. In contrast, the calcium and vitamin D contents of dairy products have been hypothesized to reduce breast cancer risk. We reviewed the current epidemiologic literature on the relation between dairy product intakes and breast cancer risk, focusing primarily on the results of cohort and case-control studies. Most of the studies reviewed showed no consistent pattern of increased or decreased breast cancer risk with a high consumption of dairy products as a whole or when broken down into high-fat and low-fat dairy products, milk, cheese, or butter. Measurement error may have attenuated any modest association with dairy products. The available epidemiologic evidence does not support a strong association between the consumption of milk or other dairy products and breast cancer risk.

Role of vitamins in the risk, prevention, and treatment of breast cancer

PURPOSE OF REVIEW

This article presents an overview of the role of vitamins in the risk, prevention, and treatment of breast cancer, with emphasis on current evidence from English-language articles published since 1 August 2002 and indexed in MEDLINE.

RECENT FINDINGS

Findings from epidemiologic studies that have evaluated vitamin A and carotenoids in relation to breast cancer risk have been inconclusive. The available data, especially from prospective studies, do not support an association between vitamins E and C and risk of breast cancer. Recent studies suggest that folate plays an important role in the prevention of breast cancer, particularly among women consuming alcohol. Limited data also support a potential role of vitamin D in the prevention of breast cancer.

SUMMARY

High intake of folate or adequate circulating levels of folate may reduce the risk of breast cancer. Adequate folate levels may be particularly important for women who are at higher risk of breast cancer because of high alcohol consumption. The inverse association between vitamin D and risk of breast cancer needs to be evaluated in more studies.

Weight Change and the Risk of Late-Onset Breast Cancer in the Original Framingham Cohort

OBJECTIVE

Adult weight gain has been associated with a twofold risk of postmenopausal breast cancer. Data are limited regarding whether weight gain at specific periods of marked changes in estrogen- and insulin-related hormones have different risk associations. This study assesses the relation of adult weight change overall and at specific, hormonally relevant times with diagnosis of a first breast cancer after age 55 (late onset).

METHODS

Framingham study data were used to assess premenopausal (25-44 yr), perimenopausal (45-55 yr), postmenopausal (after 55 yr), and adult lifetime (from 25 yr) weight change in relation to late-onset breast cancer in 2,873 women followed for up to 48 yr, with 206 late-onset breast cancers.

RESULTS

Adult lifetime weight gain was associated with an increased risk of late-onset breast cancer (P trend = 0.046). Weight gain during specific time periods was not associated with breast cancer. Data suggested a possible decreased risk of breast cancer with weight loss from ages 25 to 44 and 45 to 55 yr (relative risk = 0.4 [0.2-1.2] and 0.5 [0.3-0.9], respectively).

CONCLUSION

These data confirm prior reports of an association between adult lifetime weight gain and increased risk of late-onset breast cancer and support current recommendations to avoid adult weight gain.

Intakes of plant foods, fibre and fat and risk of breast cancer--a prospective study in the Malmö Diet and Cancer cohort

The objective of this study was to investigate prospectively the associations between intakes of plant foods, fibre and relative fat and risk of breast cancer in a subsample of 11 726 postmenopausal women in the Malmö Diet and Cancer cohort. Data were obtained by an interview-based diet history method, a structured questionnaire, anthropometrical measurements and national and regional cancer registries. During 89 602 person-years of follow-up, 342 incident cases were documented. Cox regression analysis examined breast cancer risks adjusted for potential confounders. High fibre intakes were associated with a lower risk of postmenopausal breast cancer, incidence rate ratio=0.58, 95% CI: 0.40, 0.84, for the highest quintile of fibre intake compared to the lowest quintile. The combination high fibre–low fat had the lowest risk when examining the effect in each cell of cross-classified tertiles of fibre and fat intakes. An interaction (P=0.049) was found between fibre- and fat-tertiles. There was no significant association between breast cancer risk and intakes of any of the plant food subgroups. These findings support the hypothesis that a dietary pattern characterised by high fibre and low fat intakes is associated with a lower risk of postmenopausal breast cancer.

Nutritional genomics: the next frontier in the postgenomic era

The interface between the nutritional environment and cellular/genetic processes is being referred to as “nutrigenomics.” Nutrigenomics seeks to provide a molecular genetic understanding for how common dietary chemicals (i.e., nutrition) affect health by altering the expression and/or structure of an individual’s genetic makeup. The fundamental concepts of the field are that the progression from a healthy phenotype to a chronic disease phenotype must occur by changes in gene expression or by differences in activities of proteins and enzymes and that dietary chemicals directly or indirectly regulate the expression of genomic information. We present a conceptual basis and specific examples for this new branch of genomic research that focuses on the tenets of nutritional genomics: 1) common dietary chemicals act on the human genome, either directly or indirectly, to alter gene expression or structure; 2) under certain circumstances and in some individuals, diet can be a serious risk factor for a number of diseases; 3) some diet-regulated genes (and their normal, common variants) are likely to play a role in the onset, incidence, progression, and/or severity of chronic diseases; 4) the degree to which diet influences the balance between healthy and disease states may depend on an individual’s genetic makeup; and 5) dietary intervention based on knowledge of nutritional requirement, nutritional status, and genotype (i.e., “individualized nutrition”) can be used to prevent, mitigate, or cure chronic disease.

Breast cancer risk associated with genotype polymorphism of the catechol estrogen-metabolizing genes: A multigenic study on cancer susceptibility

Estrogen has been suggested to trigger breast cancer development via an initiating mechanism involving its metabolite, catechol estrogen (CE). To examine this hypothesis, we carried out a multigenic case-control study of 469 incident breast cancer patients and 740 healthy controls to define the role of important genes involved in the different metabolic steps that protect against the potentially harmful effects of CE metabolism. We studied the 3 genes involved in CE detoxification by conjugation reactions involving methylation (catechol-O-methyltransferase, COMT), sulfation (sulfotransferase 1A1, SULT1A1), or glucuronidation (UDP-glucuronosyltransferase 1A1, UGT1A1), one (manganese superoxide dismutase, MnSOD) involved in protection against reactive oxidative species-mediated oxidation during the conversion of CE-semiquinone (CE-SQ) to CE-quinone (CE-Q), and 2 of the glutathione S-transferase superfamily, GSTM1 and GSTT1, involved in CE-Q metabolism. Support for this hypothesis came from the observations that (i) there was a trend toward an increased risk of breast cancer in women harboring a greater number of putative high-risk genotypes of these genes (p < 0.05); (ii) this association was stronger and more significant in those women who were more susceptible to estrogen [no history of pregnancy or older (> or =26 years) at first full-term pregnancy (FFTP)]; and (iii) the risks associated with having one or more high-risk genotypes were not the same in women having experienced different menarche-to-FFTP intervals, being more significant in women having been exposed to estrogen for a longer period (> or =12 years) before FFTP. Furthermore, because CE-Q can attack DNA, leading to the formation of double-strand breaks (DSB), we examined whether the relationship between cancer risk and the genotypic polymorphism of CE-metabolizing genes was modified by the genotypes of DSB repair genes, and found that a joint effect of CE-metabolizing genes and one of the two DSB repair pathways, the homologous recombination pathway, was significantly associated with breast cancer development. Based on comprehensive CE metabolizing gene profiles, our study provides support to the hypotheses that breast cancer can be initiated by estrogen exposure and that increased estrogen exposure confers a higher risk of breast cancer by causing DSB to DNA.

Apolipoprotein E and the Risk of Breast Cancer in African-American and Non-Hispanic White Women

The apolipoprotein genetic polymorphism (APO E) is part of a broader paradigm, highlighting the role of gene-environment interactions as risk factors for human diseases such as cardiovascular disease, Alzheimer’s disease, dementia, atherosclerosis, multiple sclerosis, peripheral artery disease, diabetes, stroke, and most recently, cancer. APO E, a normal constituent of very-low-density lipoproteins and high-density lipoproteins, is involved in many functions, including lipid metabolism, cholesterol transport, tissue repair, immune response and regulation, as well as cell growth and differentiation. The location, frequency and functional effects of this gene have been reviewed elsewhere in terms of cardiovascular disease, Alzheimer’s disease, neuromuscular disease, multiple sclerosis, stroke and diabetes. However, while the majority of studies have examined the significance of APO E as a molecular marker for a variety of diseases in multiethnic populations, few evaluate its role as a putative marker of cancer susceptibility. Fewer explore the importance of APO E on the risk of breast cancer, although some report an association. None have been designed to study its relevance as a marker of breast cancer risk in multiethnic populations. The purpose of this review was to evaluate the association between APO E and the risk for breast cancer in non-Hispanic white and African-American women.

Breast cancer size in postmenopausal women is correlated with body mass index and androgen serum levels

Our objective was to investigate the effects of age, weight, body mass index (BMI), sex steroid receptor status and serum parameters such as estradiol, testosterone, androstenedione, dehydroepiandrosterone sulfate (DHEAS) and leptin on the size of a malignant breast tumor. A total of 62 premenopausal (median age 44.0 years) and 151 postmenopausal (median age 59.1 years) Caucasian women undergoing lumpectomy or mastectomy for invasive breast cancer were examined. Patient parameters (age, body weight, BMI), tumor parameters (tumor size, estrogen and progesterone receptor status) and serum parameters (estradiol, testosterone, androstenedione, DHEAS and leptin) were measured. An increase of BMI and DHEAS levels was associated with larger tumors by partial correlation (rp) analysis (rp = 0.418, p = 0.008; and rp = 0.329, p = 0.041, respectively), whereas higher androstenedione levels corresponded with smaller tumors. Furthermore, BMI, androstenedione and DHEAS levels were correlated: an increase in DHEAS was associated with higher androstenedione serum concentrations (rp = 0.603, p < 0.001), but was also associated with a lower BMI (rp = -0.378, p < 0.001). BMI and androstenedione serum concentrations were also associated (rp = 0.242, p = 0.009), thus closing a circle of mutual interactions. We conclude that, although breast cancer progression is characterized by autonomous growth that has become independent of growth regulatory mechanisms, tumor size at the time of detection is influenced by a complex system of counter-regulatory feedback mechanisms that might represent the body's physiological attempt to control the size of a malignant tumor.

Breast cancer and the uptake of mammography screening services by women with intellectual disabilities

BACKGROUND

It is estimated that approximately 50% of women in Australia with intellectual disability will live to 70 years of age and as a result many will fall within the age group at highest risk for breast cancer (50-69 years).

METHODS

Subjects were identified through the Western Australia Disability Services database. To determine the number of women diagnosed with breast cancer during the period 1982-2000, individual records (n = 2,370) were linked to the Western Australia Cancer Registry and the Mammography Screening Registry.

RESULTS

The incidence of breast cancer among women with intellectual disability was 64.0 per 100,000 person-years, by comparison with 146.7 per 100,000 person-years in the general population. The uptake of breast cancer screening was examined in a subgroup of 380 women, 34.7% of whom had used mammographic screening, as opposed to 54.6% screening uptake in the general population. Failure to use screening services was highest in women who were unmarried, and was positively associated with severity of intellectual disability, presence of physical disabilities, and urban residence.

CONCLUSIONS

The lower incidence of breast cancer in women with intellectual disability may in part be attributable to decreased life expectancy, but it also appears to reflect significant under utilization of the readily available screening services.

Diet and breast cancer: evidence that extremes in diet are associated with poor survival

PURPOSE

Diet has been postulated to influence breast cancer prognosis; however, existing evidence is weak and inconsistent. Previous studies have sought evidence of a linear relationship between diet and breast cancer outcomes. Because of a U-shaped association of body mass index (BMI) with survival in breast cancer, we hypothesized that a nonlinear association also existed for dietary variables.

PATIENTS AND METHODS

Four hundred seventy-seven women with surgically resected T1 to T3, N0/1, M0 breast cancer completed the Block Food Frequency Questionnaire 9.3 +/- 4.6 weeks (mean +/- standard deviation) after diagnosis, reporting intake over the preceding 12 months. Data on tumor-related factors, treatment, and outcomes were obtained prospectively from medical records. A series of Cox models was performed, modeling the association of dietary factors with breast cancer survival linearly and quadratically, adjusting for total energy intake, tumor- and treatment-related variables, and BMI.

RESULTS

Significant nonlinear survival associations were found for protein, oleic acid, cholesterol, polyunsaturated-saturated fat ratio, and for percentage of calories from fat and percentage of calories from carbohydrates in multivariate models. The shape of the survival associations varied across nutrients. Hazard ratios for highest risk quintiles ranged from 2.1 to 6.5. For total fat, adjustment for BMI reduced the multivariate P value obtained from nonlinear Cox models from.05 to.10. No significant linear associations were identified.

CONCLUSION

The association of key dietary variables with breast cancer survival may be U-shaped rather than linear. Our data suggest that midrange intake of most major energy sources is associated with the most favorable outcomes, and extremes are associated with less favorable outcomes.

Measuring dietary fatty acid intake:validation of a food-frequency questionnaire against 7 d weighed records

There are few validated methods of measuring dietary fatty acid intake that are suitable for epidemiological research. The purpose of the present study was to develop and validate a food-frequency questionnaire (FFQ) developed to measure individual dietary fatty acid intakes against 7 d weighed dietary records, in a sample of thirty-one healthy adult volunteers. The FFQ was based on a previously validated questionnaire (DIETQ; Tinuviel Software, Warrington, Ches., UK), adapted to include greater detail on those foods from which the majority of dietary fatty acids are obtained. The FFQ and weighed records were analysed using food nutrient data from McCance and Widdowson's Food Composition Tables, supplemented with a food fatty acid content database (Foodbase, London, UK). Results from the two dietary assessment methods were compared by correlation coefficients and limits of agreement. The mean intake of individual fatty acids tended to be lower when assessed by FFQ. Correlation coefficients comparing unadjusted individual fatty acid intakes assessed by FFQ and weighed records ranged from 0.29 for 18 : 1n-9 to 0.71 for 20 : 4n-6. Adjusting for energy intake tended to increase the correlation coefficients between saturated fatty acids and decrease those between unsaturated fatty acids. In conclusion, this food-frequency method provides reliable estimates of dietary intake of many individual fatty acids for use in epidemiological studies.

Inhibition of proliferation of PC3 cells by the branched-chain fatty acid, 12-methyltetradecanoic acid, is associated with inhibition of 5-lipoxygenase

BACKGROUND

Branched-chain fatty acids or fatty alcohols have been reported to possess anti-tumor activity in various tumor models. Here we study 12-methyltetradecanoic acid (12-MTA), a branched-chain fatty acid, isolated from a sea cucumber extract, on the growth of prostate cancer cells and investigate the underlying mechanisms of its effect.

METHODS

12-MTA was evaluated by MTT assay for its ability to inhibit cell proliferation in various cancer types. The ability of 12-MTA to induce apoptosis of PC3 cells was examined by morphologic changes, propidium iodide (PI) staining, and caspase-3 activation. Furthermore, alteration of eicosanoid metabolism by 12-MTA was examined in PC3 and RBL-1 cells and in purified lipoxygenase (LOX) and cyclooxygenase (COX) enzymes.

RESULTS

12-MTA inhibited proliferation of various cell lines, with IC50s ranging from 17.99 to 35.44 microg/ml. PI staining clearly showed that 12-MTA caused PC3 cell death through induction of apoptosis. At 50 microg/ml, 12-MTA increased caspase-3 activity four to seven-fold compared with that in control cells. Examination of cellular arachidonate metabolism showed that at 25 microg/ml, 12-MTA reduced the level of 5-hydroxyeicosatetraenoic acid (5-HETE) by 45%. Furthermore, exogenous 5-HETE protects PC3 cells from 12-MTA induced cell death.

CONCLUSIONS

12-MTA inhibited proliferation of cancer cells via apoptosis, in which caspase-3 may play a role. At relevant concentrations, 12-MTA can selectively inhibit the formation of 5-HETE, a metabolite of 5-lipoxygenase. This agent may be a novel adjunctive therapy for selected malignancies including prostate cancer.

Nutrition and breast cancer risk by age 50: a population-based case-control study in Germany

Diet is recognized to play a role in the occurrence of breast cancer; however, the data are inconsistent. The goal of this study was to determine the influence of dietary factors on breast cancer risk among women up to 50 yr of age in a German population. A population-based case-control study was conducted including 706 cases and 1,381 controls. In addition to a risk factor questionnaire, a subgroup of 355 cases and 838 controls completed a food frequency questionnaire. Breast cancer risk was inversely associated with vegetable consumption (P for trend = 0.034). The odds ratio for the fourth quartile of vegetable intake compared with the first quartile was 0.64 (95% confidence interval = 0.43-0.96). Breast cancer risk increased with a higher consumption of red meat (P for trend = 0.016); women with the highest consumption level had an 85% elevated breast cancer risk compared with the lowest quartile (95% confidence interval = 1.23-2.78). When only premenopausal women were considered, the protective effect of vegetable intake and the positive association with meat intake were even stronger. These results are compatible with the international recommendations for a breast cancer preventive diet and suggest that the favorable effect of a diet high in vegetables and low in red meat, especially beef, may be stronger in premenopausal women.

Women's perspectives on nutrition, health, and breast cancer

OBJECTIVE

To explore women's beliefs about diet, health, and breast cancer.

DESIGN

Individual interviews exploring women's perceptions of their eating habits, health status, and diet, health, and breast cancer beliefs.

SETTING

Vancouver, British Columbia, Canada.

PARTICIPANTS

A culturally diverse convenience sample of women aged 40 to 60 years, including breast cancer survivors (n = 29) and women who had not had breast cancer (n = 32).

ANALYSIS

Verbatim interview transcripts were coded and themes developed by sorting and summarizing coded transcript segments.

RESULTS

Three perspectives on healthful eating were identified. A "traditional" perspective stressed regular meals of meat, potatoes, and vegetables and made no specific claims about the diet-breast cancer relationship. A "mainstream" perspective stressed increasing vegetables and fruits and decreasing fat intake to improve health, reduce cardiovascular disease risk, and, possibly, reduce breast cancer risk. An "alternative" perspective focused on the role of toxins, carcinogens, and protective factors in food in affecting cancer risk.

CONCLUSIONS AND IMPLICATIONS

Although overall perspectives on healthful eating were not related to participants' breast cancer status, they were related to how participants thought about the relationships between diet and breast cancer. Specific diet-cancer beliefs, degree of conviction about those beliefs, and reasons why foods are believed to be protective or harmful are indicative of overall nutrition perspectives.

The Eating Behavior Patterns Questionnaire predicts dietary fat intake in African American women

OBJECTIVE

To develop a behavioral assessment of eating that would be predictive of fat intake in African American women.

DESIGN

Questionnaires were developed using a three-stage design, involving item generation, item refinement, and questionnaire validation.

SUBJECTS

Focus groups sessions were conducted with 40 African American women, initial questionnaire development employed 80 African American women, and questionnaire validation involved 310 African American women from diverse socioeconomic backgrounds. Statistical analyses Transcripts of focus groups were used to generate 113 behavioral questionnaire items. The initial questionnaire was administered along with a food frequency questionnaire, and the item pool was reduced to 51 items. Factor analysis was used to create subscales. Correlation (r) and multiple regression analysis (R) were used to evaluate construct validity.

RESULTS

Factor analysis revealed six subscales: low-fat eating, emotional eating, snacking on sweets, cultural/ethnic, haphazard planning, and meal skipping. The scales are significant predictors of micronutrient (R values from 0.22 to 0.47) and macronutrient intakes (R values from 0.33 to 0.58) assessed using a food frequency questionnaire and show construct validity in relationship to other measures of eating behavior (r values from 0.22 to 0.65).

APPLICATIONS

The Eating Behavior Patterns Questionnaire (EBPQ) may be a useful tool for clinical assessment, clinical and community nutrition intervention studies, and epidemiologic research with African American women.

A prospective study of adiposity and postmenopausal breast cancer risk: the Malmö Diet and Cancer Study

High BMI is a well-known risk factor for postmenopausal breast cancer. There have been some reports of excess risk in association with weight gain and WHR, but little is known about the influence of body fatness per se. Using data from the Malmö Diet and Cancer Study, a prospective cohort study, 12,159 postmenopausal women (59.9 +/- 7.7 years) were categorized by quintiles of baseline anthropometric and impedance measures and reported weight change since age 20. RRs from multivariate Cox regression models were calculated. All analyses were adjusted for age, height, smoking, alcohol consumption, occupation, marital status, parity, age at first pregnancy, age at menarche and current hormone use. During the 5.7 years of follow-up, there were 246 incident breast cancer cases. Weight, height, BMI and %BF were positively associated with risk of breast cancer (p(trend) <or= 0.02). %BF showed the strongest association, with an RR of 2.01 (95% CI 1.26-3.21) in the highest vs. lowest quintile. There was significant modification of this association by hormone use, suggesting a greater impact of body fatness among nonusers. Fat distribution was not independently associated with breast cancer risk. Women with weight gain >21 kg (top quintile) had an RR of 1.75 (95% CI 1.11-2.77) compared to women with low weight gain. Breast cancer risk in postmenopausal women is predicted by increased body fat and weight gain. %BF is a more discriminating risk factor for breast cancer incidence than the commonly used BMI.

Serum enterolactone concentration is not associated with breast cancer risk in a nested case-control study

The lignan enterolactone produced by the intestinal microflora from dietary precursors has been hypothesized to protect against hormone-dependent cancers. We conducted a nested case-control study to examine the relationship between serum enterolactone concentration and risk of breast cancer. Enterolactone concentrations were measured by time-resolved fluoroimmunoassay in serum collected at 4 independent cross-sectional population surveys from 206 women with breast cancer diagnosed during follow-up (mean 8.0 years) and from 215 controls frequency-matched to cases by study cohort, 5-year age group and study area. Mean serum enterolactone concentration (nmol/l) did not significantly differ between case and control subjects [25.2 (SD 22.2) vs. 24.0 (SD 21.3), respectively]. Odds ratios for breast cancer risk estimated by conditional logistic regression for increasing concentration of enterolactone in quartiles were 1.00 (referent), 1.67 (95% CI 0.95-2.95), 1.71 (95% CI 0.96-3.06) and 1.30 (95% CI 0.73-2.31), and p for trend was 0.48. Our findings do not support the hypothesis that high serum enterolactone concentration is associated with reduced risk of breast cancer.