Use of iDXA spine scans to evaluate total and visceral abdominal fat.

OBJECTIVES: Abdominal fat may be a better predictor than body mass index (BMI) for risk of metabolically-related diseases, such as diabetes, cardiovascular disease, and some cancers. We sought to validate the percent fat reported on dual energy X-ray absorptiometry (DXA) regional spine scans (spine fat fraction, SFF) against abdominal fat obtained from total body scans using the iDXA machine (General Electric, Madison, WI), as previously done on the Prodigy model. METHODS: Total body scans and regional spine scans were completed on the same day (N = 50). In alignment with the Prodigy-based study, the following regions of interest (ROI) were assessed from total body scans and compared to the SFF from regional spine scans: total abdominal fat at (1) lumbar vertebrae L2-L4 and (2) L2-Iliac Crest (L2-IC); (3) total trunk fat; and (4) visceral fat in the android region. Separate linear regression models were used to predict each total body scan ROI from SFF; models were validated by bootstrapping. RESULTS: The sample was 84% female, a mean age of 38.5 ± 17.4 years, and mean BMI of 23.0 ± 3.8 kg/m2 . The SFF, adjusted for BMI, predicted L2-L4 and L2-IC total abdominal fat (%; Adj. R2 : 0.90) and total trunk fat (%; Adj. R2 : 0.88) well; visceral fat (%) adjusted R2 was 0.83. Linear regression models adjusted for additional participant characteristics resulted in similar adjusted R2 values. CONCLUSIONS: This replication of the strong correlation between SFF and abdominal fat measures on the iDXA in a new population confirms the previous Prodigy model findings and improves generalizability.

Visceral adiposity and cancer survival: a review of imaging studies.

Although obesity is a well-known risk factor for cancer, the association between obesity and cancer survival remains controversial. This is partially due to the inability of conventional obesity measures to directly assess adiposity or adipose tissue distribution. As a metabolic organ, visceral adipose tissue (VAT) secrets a variety of cytokines and cytokine-like factors, potentially affecting cancer survival. The objective of this review was to investigate the influence of imaging-assessed VAT on cancer survival. A total of 22 studies assessing the impact of visceral adiposity on survival were included. Negative associations between VAT and survival were more frequently observed among patients with colorectal (four of six studies) and pancreatic (three of five studies) cancers, compared to higher VAT predicting longer survival in most studies of renal cell carcinoma patients (four of five studies). Methodological limitations, including unstandardised VAT measurement methods, lack of other body composition measurement (i.e. muscle mass), small sample size and heterogeneous cohort characteristics, may explain controversial findings related to the impact of VAT on cancer survival.

Dual energy X-ray absorptiometry spine scans to determine abdominal fat in postmenopausal women.

Body composition may be a better predictor of chronic disease risk than body mass index (BMI) in older populations. OBJECTIVES: We sought to validate spine fat fraction (%) from dual energy X-ray absorptiometry (DXA) spine scans as a proxy for total abdominal fat. METHODS: Total body DXA scan abdominal fat regions of interest (ROI) that have been previously validated by magnetic resonance imaging were assessed among healthy, postmenopausal women who also had antero-posterior spine scans (n = 103). ROIs were (1) lumbar vertebrae L2-L4 and (2) L2-Iliac Crest (L2-IC), manually selected by two independent raters, and (3) trunk, auto-selected by DXA software. Intra-class correlation coefficients evaluated intra and inter-rater reliability on a random subset (N = 25). Linear regression models, validated by bootstrapping, assessed the relationship between spine fat fraction (%) and total abdominal fat (%) ROIs. RESULTS: Mean age, BMI, and total body fat were 66.1 ± 4.8 y, 25.8 ± 3.8 kg/m2 and 40.0 ± 6.6%, respectively. There were no significant differences within or between raters. Linear regression models adjusted for several participant and scan characteristics were equivalent to using only BMI and spine fat fraction. The model predicted L2-L4 (Adj. R2 : 0.83) and L2-IC (Adj. R2 : 0.84) abdominal fat (%) well; the adjusted R2 for trunk fat (%) was 0.78. Model validation demonstrated minimal over-fitting (Adj. R2 : 0.82, 0.83, and 0.77 for L2-L4, L2-IC, and trunk fat, respectively). CONCLUSIONS: The strong correlation between spine fat fraction and DXA abdominal fat measures make it suitable for further development in postmenopausal chronic disease risk prediction models. Am. J. Hum. Biol. 28:918-926, 2016. © 2016Wiley Periodicals, Inc.

Mismatch repair polymorphisms and risk of colon cancer, tumour microsatellite instability and interactions with lifestyle factors.

BACKGROUND: Germline mutations in DNA mismatch repair (MMR) genes cause Lynch syndrome colon cancers. Less understood is the risk of colon cancer associated with common polymorphisms in MMR genes and the potential interacting role of lifestyle factors known to damage DNA. METHODS: A study was conducted to examine whether MLH1 (-93G>A and Ile219Val) and MSH6 (Gly39Glu) polymorphisms were associated with risk of colon cancer in data from 1609 colon cancer cases and 1972 controls. Genotype data were further stratified by microsatellite instability status, smoking, alcohol, Western diet, alcohol and obesity, to investigate potential heterogeneity. RESULTS: The MSH6 39Glu allele was associated with increased risk of colon cancer among men (Gly/Glu or Glu/Glu vs Gly/Gly, OR 1.27; 95% CI 1.04 to 1.54). Neither MLH1 polymorphism was associated with colon cancer risk overall. When stratified by microsatellite stability status, however, the MLH1 -93A allele was associated with a more than doubling in microsatellite instability (MSI)-positive colon cancer risk (AA vs GG, OR 2.47; 95% CI 1.48 to 4.11); no associations were observed between the MMR polymorphisms examined and MSI-negative colon cancer. Statistically significant interactions were observed between: MLH1 -93G>A and smoking (MSI-negative colon cancer only, p value interaction: 0.005); and MLH1 Ile219Val and Western diet (p value interaction: 0.03). CONCLUSIONS: The MSH6 Gly39Glu and MLH1 -93G>A polymorphisms were associated with risk of overall colon and MSI-positive colon cancers, respectively. Risk for colon cancer, stratified by MMR genotype, was further modified by smoking and Western diet.

The effect of conjugated equine oestrogen on diabetes incidence: the Women's Health Initiative randomised trial.

AIMS/HYPOTHESIS: Recent clinical trials have found that the combination of conjugated equine oestrogen (CEO) and medroxyprogesterone has a protective effect on the incidence of type 2 diabetes. To determine the effect of CEO alone on the incidence of diabetes mellitus in postmenopausal women, we analysed the results of the Women's Health Initiative oestrogen-alone trial. METHODS: The Women's Health Initiative is a randomised, double-masked trial comparing the effect of daily 0.625 mg CEO with placebo during 7.1 years of follow-up of 10,739 postmenopausal women who were aged 50-79 years and had previously had a hysterectomy. Diabetes incidence was ascertained by self-report of treatment with insulin or oral hypoglycaemic medication. Fasting glucose, insulin and lipoproteins were measured in an 8.6% random sample of study participants, at baseline and at 1, 3 and 6 years. RESULTS: The cumulative incidence of treated diabetes was 8.3% in the oestrogen-alone group and 9.3% in the placebo group (hazard ratio 0.88, 95% CI 0.77-1.01, p=0.072). During the first year of follow-up, a significant fall in insulin resistance (homeostasis model assessment of insulin resistance) in actively treated women compared with the control subjects (Year 1 baseline between-group difference -0.53) was seen. However, there was no difference in insulin resistance at the 3- or 6-year follow-up. CONCLUSIONS/INTERPRETATION: Postmenopausal therapy with oestrogen alone may reduce the incidence of treated diabetes. The effect is smaller than that seen with oestrogen plus progestin. CEO should not, however, be used with the intention of preventing diabetes, as its well-described adverse effects preclude long-term use for primary prevention.

MTHFR variants reduce the risk of G:C->A:T transition mutations within the p53 tumor suppressor gene in colon tumors.

5,10-Methylene-tetrahydrofolate reductase (MTHFR) is a key enzyme in folate-mediated 1-carbon metabolism. Reduced MTHFR activity has been associated with genomic DNA hypomethylation. Methylated cytosines at CpG sites are easily mutated and have been implicated in G:C-->A:T transitions in the p53 tumor suppressor gene. We investigated 2 polymorphisms in the MTHFR gene (C677T and A1298C) and their associations with colon tumor characteristics, including acquired mutations in Ki-ras and p53 genes and microsatellite instability (MSI). The study population comprised 1248 colon cancer cases and 1972 controls, who participated in a population-based case-control study and had been analyzed previously for MSI, acquired mutations in Ki-ras, p53, and germline MTHFR polymorphisms. Multivariable-adjusted odds ratios are presented. Overall, MTHFR genotypes were not associated with MSI status or the presence of any p53 or Ki-ras mutation. Individuals with homozygous variant MTHFR genotypes had a significantly reduced risk of G:C-->A:T transition mutations within the p53 gene, yet, as hypothesized, only at CpG-associated sites [677TT vs. 677CC (referent group) OR = 0.4 (95% CI: 0.1-0.8) for CpG-associated sites; OR = 1.5 (0.7-3.6) for non-CpG associated sites]. Genotypes conferring reduced MTHFR activity were associated with a decreased risk of acquired G:C-->A:T mutations within the p53 gene occurring at CpG sites. Consistent with evidence on the phenotypic effect of the MTHFR C677T variant, we hypothesize that this relation may be explained by modestly reduced genomic DNA methylation, resulting in a lower probability of spontaneous deamination of methylated cytosine to thymidine. These results suggest a novel mechanism by which MTHFR polymorphisms can affect the risk of colon cancer.

Meat intake and the recurrence of colorectal adenomas.

A large multicenter randomized controlled trial was re-assessed to check whether meat intake and a reduction in its consumption are associated with recurrence of adenomatous polyps of the large bowel, which are precursors of most colorectal malignancies. All subjects (n = 1905; 958 interventions and 947 controls) had one or more histologically confirmed colorectal adenomas removed during a colonoscopy within 6 months before randomization. The subjects were followed-up for approximately 4 years after randomization and a colonoscopy for detecting adenomas was conducted at the 1st and 4th year after randomization. Dietary variables were assessed at baseline (T0) and in conjunction with annual visits at the end of the 1st (T1), 2nd (T2), 3rd (T3) and 4th (T4) years. Odds ratios using logistic regression models for meat variables were estimated based on the average intake at T0, T1, T2, T3 and T4 (prior to the T4 colonoscopy) as well as change (T0-T4) in intake. In the intervention group, the total reduction in median intake of red meat from T0 to T4 was observed by the end of 1st year itself (30 and 31% for men and women, respectively). The analysis provide no evidence to suggest that lower intake or reduction in total and in red meat consumption during a period of 4 years reduces the risk of adenoma recurrence (including multiple or advanced adenoma), whereas the data suggest that high intake of fish is associated with lower risk of adenoma recurrence.

Habitual tea consumption and risk of osteoporosis: a prospective study in the women's health initiative observational cohort.

The purpose of this study was to prospectively investigate associations of habitual drinking of regular tea with bone mineral density and fracture risk. Study participants were a multiethnic postmenopausal cohort (n = 91,465) from the nationwide Women's Health Initiative Observational Study. These women were recruited in the United States and aged 50-79 years at the time of enrollment (1994-1998). The average follow-up time was 4.1 years. Habitual consumption of regular tea was assessed with a structured questionnaire at baseline. Clinical fractures during the follow-up were reported in questionnaires, and hip fractures were further confirmed by reviewing medical records. Bone mineral density measurements were conducted among a subgroup of women (n = 4,979) at three Women's Health Initiative bone mineral density centers using dual-energy x-ray absorptiometry. Multivariate analyses suggested a positive trend of increased total body bone mineral density with tea drinking (p < 0.05). However, results from the Cox proportional hazard models did not show any significant association between tea drinking and the risk of fractures at the hip and forearm/wrist. In conclusion, the results from this study indicate that the effect of habitual tea drinking on bone density is small and does not significantly alter the risk of fractures among the US postmenopausal population.

Hormone replacement therapy and colorectal adenoma recurrence among women in the Polyp Prevention Trial.

BACKGROUND: Epidemiologic studies have suggested that estrogen may protect against the development of colorectal cancers and adenomatous polyps. We conducted a prospective study to evaluate the association between hormone replacement therapy (HRT) and adenoma recurrence among perimenopausal and postmenopausal women participating in the Polyp Prevention Trial, a randomized dietary intervention study of individuals with colorectal adenomas. METHODS: We used a questionnaire and interviews to collect detailed information, at baseline and at each of four annual study visits, from 620 women regarding hormone use, menopausal status, diet, alcohol consumption, and other risk factors. Adenoma recurrence was ascertained by complete colonoscopy at baseline and after 1 and 4 years. Logistic regression models were used to evaluate the association between hormone use and adenoma recurrence after adjusting for intervention group and for age and body mass index at baseline. All statistical tests were two-sided. RESULTS: Adenomas recurred in 200 women. There was no overall association between adenoma recurrence and either overall hormone use (odds ratio [OR] = 1.01; 95% confidence interval [CI] = 0.70 to 1.45), combined estrogen and progestin use (OR = 0.94; 95% CI = 0.57 to 1.56), or unopposed estrogen use (OR = 1.04; 95% CI = 0.68 to 1.59). HRT use was associated with a reduction in risk for recurrence of distal adenomas (OR = 0.56; 95% CI = 0.32 to 1.00) and a statistically nonsignificant increase in risk for recurrence of proximal adenomas (OR = 1.39; 95% CI = 0.85 to 2.26). We observed a statistically significant interaction between the HRT-adenoma recurrence association and age (P =.02). HRT was associated with a 40% reduced risk of adenoma recurrence among women older than 62 years (OR = 0.58; 95% CI = 0.35 to 0.97) but with an increased risk among women younger than 62 years (OR = 1.99; 95% CI = 1.11 to 3.55). CONCLUSIONS: HRT was not associated with a reduced risk for overall adenoma recurrence in this trial cohort, although there was a suggestion of an age interaction. The effect of age on the association needs to be confirmed in other adenoma recurrence trials.

Implementation of a 4-y, high-fiber, high-fruit-and-vegetable, low-fat dietary intervention: results of dietary changes in the Polyp Prevention Trial.

BACKGROUND: The Polyp Prevention Trial (PPT) was a multicenter randomized clinical trial designed to determine the effects of a high-fiber (4.30 g/MJ), high-fruit-and-vegetable (0.84 servings/MJ), low-fat (20% of energy from fat) diet on the recurrence of adenomatous polyps in the large bowel. OBJECTIVE: Our goal was to determine whether the PPT intervention plan could effect change in 3 dietary goals and to examine the intervention's effect on the intake of other food groups and nutrients. DESIGN: Participants with large-bowel adenomatous polyps diagnosed in the past 6 mo were randomly assigned to either the intervention (n = 1037) or the control (n = 1042) group and remained in the trial for 4 y. Three dietary assessment instruments were used to measure dietary change: food-frequency questionnaires (in 100% of the sample), 4-d food records (in a 20% random cohort), and 24-h dietary recalls (in a 10% random sample). RESULTS: Intervention participants made and sustained significant changes in all PPT goals as measured by the dietary assessment instruments; the control participants' intakes remained essentially the same throughout the trial. The absolute differences between the intervention and control groups over the 4-y period were 9.7% of energy from fat (95% CI: 9.0%, 10.3%), 1.65 g dietary fiber/MJ (95% CI: 1.53, 1.74), and 0.27 servings of fruit and vegetables/MJ (95% CI: 0.25, 0.29). Intervention participants also reported significant changes in the intake of other nutrients and food groups. The intervention group also had significantly higher serum carotenoid concentrations and lower body weights than did the control group. CONCLUSION: Motivated, free-living individuals, given appropriate support, can make and sustain major dietary changes over a 4-y period.

Correlates of serum alpha- and gamma-tocopherol in the Women's Health Initiative.

PURPOSE: There is increasing evidence that vitamin E (primarily alpha- and gamma-tocopherol) may reduce the risk of cardiovascular disease and some cancers, therefore it is important to understand factors that influence blood levels. METHODS: The correlates of serum alpha- and gamma-tocopherol were investigated among participants in the Women's Health Initiative (WHI), a 40-site disease prevention trial. Subjects were 1047 postmenopausal women aged 50-79 years, who provided fasting blood specimens and detailed information on diet, supplement use, and other factors at entry to the study (1994-96). RESULTS: Total serum cholesterol and triglycerides were highly correlated with serum alpha- and gamma-tocopherol concentrations and were controlled for in all analyses along with age, ethnicity and body mass index (BMI). Alpha and gamma-tocopherol were strongly negatively correlated (partial r = -0.69). The strongest predictor of serum tocopherols was average daily intake of vitamin E from supplements (partial r = 0.60 for alpha, r = -0.54 for gamma). Other factors associated with increased alpha- and/or decreased gamma-tocopherol concentrations were serum retinol and carotenoids, supplemental vitamin C, alpha-tocopherol intake from food, dietary fiber, and Hispanic ethnicity. Factors associated with lower alpha- and/or higher gamma-tocopherol concentrations included gamma-tocopherol intake from food, total fat intake, and BMI. Age, income, hormone use, and geographic location were "spuriously" associated with serum tocopherol levels through their association with supplement use, i.e., there was no such association among the subset of women not taking supplements. CONCLUSIONS: Vitamin E intake from supplements and BMI are the major independent predictors of serum tocopherol levels in women, whereas dietary factors only play a small role.

Reduction in fat intake is not associated with weight loss in most women after breast cancer diagnosis: evidence from a randomized controlled trial.

BACKGROUND: A reduction in dietary fat intake has been suggested as a method to promote weight loss in women at risk for breast cancer recurrence. METHODS: Weight change in response to diet intervention was examined in 1010 women who had completed treatment for Stage I, Stage II, or Stage IIIA (American Joint Committee on Cancer staging system) primary operable breast cancer during their first year of participation in a randomized, controlled, diet intervention trial to reduce risk of recurrence. Diet intervention was performed by telephone counseling and promoted a low fat diet that also was high in fiber, vegetables, and fruit. The comparison group was provided with general dietary guidelines to reduce disease risk. Multiple linear regression models were used to examine the relations among demographic and personal characteristics, changes in diet composition and exercise level, and change in body weight or body mass index. RESULTS: The average weight change in the 1-year period was 0.04 kg for the intervention group and 0.46 kg for the comparison group. For the total group, body weight was stable (+/- 5% baseline weight) for 743 women (74%), whereas 114 (11%) lost weight, and 153 (15%) gained weight. These distributions were similar in the two study groups inclusive of all study participants and for only those women with a baseline body mass index of > or = 25 kg/m2. Initial body mass index and changes in fiber and vegetable intakes, but not change in percent of energy obtained from fat, were associated independently with change in weight or body mass index. CONCLUSIONS: For most women at risk for breast cancer recurrence, diet intervention to promote a reduction in fat intake was not associated with significant weight loss. Testing the effect of a substantial change in diet composition on risk for breast cancer recurrence is unlikely to be confounded by weight loss in subjects who were the recipients of intensive intervention efforts.

Low-energy reporting in women at risk for breast cancer recurrence. Women's Healthy Eating and Living Group.

This study examined the extent of low-energy reporting and its relationship with demographic and lifestyle factors in women previously treated for breast cancer. This study used data from a large multisite clinical trial testing the efficacy of a dietary intervention to reduce risk for breast cancer recurrence (Women's Healthy Eating and Living Study). Using the Schofield equation to estimate energy needs and four 24-h dietary recalls to estimate energy intakes, we identified women who reported lower than expected energy intakes using criteria developed by G. R. Goldberg et al. (Eur. J. Clin. Nutr., 45: 569-581, 1991). We examined data from 1137 women diagnosed with stage I, stage II, or stage IIIA primary, operable breast cancer. Women were 18-70 years of age at diagnosis and were enrolled in the Women's Healthy Eating and Living Study between August 19, 1995, and April 1, 1998, within 4 years after diagnosis. The Goldberg criteria classified about one-quarter (25.6%) as low-energy reporters (LERs) and 10.8% as very LERs. Women who had a body mass index >30 were almost twice (odds ratio, 1.95) as likely to be LERs. Women with a history of weight gain or weight fluctuations were one and a half times as likely (odds ratio, 1.55) to be LERs as those who were weight stable or weight losers. Age, ethnicity, alcohol intake, supplement use, and exercise level were also related to LER. Characteristics (such as body mass index, age, ethnicity, and weight history) that are associated with low-energy reporting in this group of cancer survivors are similar to those observed in other populations and might affect observed diet and breast cancer associations in epidemiological studies.

Interplay between dietary inducers of GST and the GSTM-1 genotype in colon cancer.

The purpose of this study is to determine if cruciferous vegetables and coffee, two dietary inducers of glutatione-S-transferases, interact with GSTM-1 genotype to alter risk of colon cancer. Data were available on 1579 incident cases of adenocarcinoma of the colon and 1898 population-based controls. Intake of cruciferous vegetables, specific types of cruciferous vegetable, and coffee were not associated with colon cancer; GSTM-1 genotype did not modify these associations. However, age at diagnosis and cigarette smoking appeared to be important effect modifiers of the associations between GSTM-1, cruciferous vegetables and colon cancer. Among GSTM-1 null individuals, <55 years at diagnosis, we observed an inverse association between colon cancer and high levels of cruciferous vegetable intake relative to people who did not eat cruciferous vegetables (ORs 0.23 95% CI 0.10-0.54); broccoli was the cruciferous vegetable associated with the strongest inverse association (OR 0.30 95% CI 0.13-0.70). Among younger individuals who were GSTM-1 present (relative to those with GSTM-1 null), we observed an inverse association with colon cancer regardless of level of cruciferous vegetable intake (OR 0.74 95% CI 0.30-1.79 for no intake; OR 0.44 95% CI 0.21-0.92 for <4 servings/week; and OR 0. 44 95% CI 0.19-0.99 for >/=4 servings/week). These associations were further modified by cigarette smoking. People <65 years of age who smoked had a greater reduction in risk of colon cancer from consumption of cruciferous vegetables than non-smokers at the same age. In summary, although cruciferous vegetables do not appear to modify colon cancer risk in the total population, there are subgroups of the population for whom these vegetables may be important. These subgroups are defined mostly by age and smoking status.

Calcium, vitamin D, sunshine exposure, dairy products and colon cancer risk (United States).

OBJECTIVE: Epidemiologic studies on calcium, vitamin D and colon cancer are inconsistent, whereas experimental studies more regularly show a protective effect. To evaluate potential sources of inconsistencies, data from a large case-control study were analyzed, stratifying on potential effect modifiers. METHODS: Data were collected by certified interviewers in Northern California, Utah and Minnesota. Analyses included 1993 incident colon cancer cases and 2410 population-based controls. Multivariate logistic regression models included age, sex, BMI, family history, physical activity, intake of energy, dietary fiber, aspirin and NSAIDs. RESULTS: Dietary calcium was inversely associated with colon cancer risk in men (OR highest vs lowest quintile = 0.6, 95% CI = 0.5-0.9) and women (OR = 0.6, 95% CI = 0.4-0.9). No statistically significant associations were observed for dietary vitamin D or sunshine exposure. Consumption of total low-fat dairy products was associated with a statistically significantly decreased risk in men and women (ORs highest vs lowest category of intake = 0.8 and 0.7 respectively). Calcium supplement use was inversely associated with risk in both sexes (ORs use vs non-use = 0.8). Vitamin D supplements were inversely associated with risk in men (OR = 0.5) and women (OR = 0.6) but confidence limits included 1.0. CONCLUSIONS: These data provide additional support of an inverse association between high levels of calcium intake and colon cancer risk.

Lack of effect of a low-fat, high-fiber diet on the recurrence of colorectal adenomas. Polyp Prevention Trial Study Group.

BACKGROUND: We tested the hypothesis that dietary intervention can inhibit the development of recurrent colorectal adenomas, which are precursors of most large-bowel cancers. METHODS: We randomly assigned 2079 men and women who were 35 years of age or older and who had had one or more histologically confirmed colorectal adenomas removed within six months before randomization to one of two groups: an intervention group given intensive counseling and assigned to follow a diet that was low in fat (20 percent of total calories) and high in fiber (18 g of dietary fiber per 1000 kcal) and fruits and vegetables (3.5 servings per 1000 kcal), and a control group given a standard brochure on healthy eating and assigned to follow their usual diet. Subjects entered the study after undergoing complete colonoscopy and removal of adenomatous polyps; they remained in the study for approximately four years, undergoing colonoscopy one and four years after randomization. RESULTS: A total of 1905 of the randomized subjects (91.6 percent) completed the study. Of the 958 subjects in the intervention group and the 947 in the control group who completed the study, 39.7 percent and 39.5 percent, respectively, had at least one recurrent adenoma; the unadjusted risk ratio was 1.00 (95 percent confidence interval, 0.90 to 1.12). Among subjects with recurrent adenomas, the mean (+/-SE) number of such lesions was 1.85+/-0.08 in the intervention group and 1.84+/-0.07 in the control group. The rate of recurrence of large adenomas (with a maximal diameter of at least 1 cm) and advanced adenomas (defined as lesions that had a maximal diameter of at least 1 cm or at least 25 percent villous elements or evidence of high-grade dysplasia, including carcinoma) did not differ significantly between the two groups. CONCLUSIONS: Adopting a diet that is low in fat and high in fiber, fruits, and vegetables does not influence the risk of recurrence of colorectal adenomas.

Western diet, family history of colorectal cancer, NAT2, GSTM-1 and risk of colon cancer.

OBJECTIVE: In this study we examine the combined effects of Western diet, age at diagnosis, and genetic susceptibility. METHODS: We use data collected as part of an incident case-control study of colon cancer. Family history of colorectal cancer, N-acetyltransferase (NAT2), and glutathione-S-transferase (GSTM-1) are studied with Western diet and age at diagnosis. RESULTS: A significant interaction between age at time of diagnosis, Western dietary pattern, and family history of colorectal cancer (p for interaction = 0.03) was detected. Those with a family history of colorectal cancer who ate a predominantly Western diet were at increased risk of colon cancer (OR 14.0, 95% CI 3.9-50.1 for < or = 55 years; OR 7.7, 95% CI 2.0-29.1 for 56-66 years; OR 1.6, 95% CI 0.8-3.2 for > or = 67 years) compared to those without a family history of colorectal cancer and low levels of a Western diet. Associations with the Western diet were stronger than individual components of the dietary pattern. Neither NAT2 nor GSTM-1 showed significant interaction with Western diet. CONCLUSION: The extent to which diet comprising a Western dietary pattern influences risk of colon cancer is dependent on age. This dietary pattern also appears to modulate the colon cancer risk associated with a family history of colon cancer.

Lifestyle and colon cancer: an assessment of factors associated with risk.

Studies of the etiology of colon cancer indicate that it is strongly associated with diet and lifestyle factors. The authors use data from a population-based study conducted in northern California, Utah, and Minnesota in 1991-1995 to determine lifestyle patterns and their association with colon cancer. Data obtained from 1,993 cases and 2,410 controls were grouped by using factor analyses to describe various aspects of lifestyle patterns. The first five lifestyle patterns for both men and women loaded heavily on dietary variables and were labeled: "Western," "moderation," "calcium/low-fat dairy;" "meat and mutagens," and "nibblers, smoking, and coffee." Other important lifestyle patterns that emerged were labeled "body size," "medication and supplementation," "alcohol," and "physical activity." Among both men and women, the lifestyle characterized by high levels of physical activity was the most marked lifestyle associated with colon cancer (odds ratios = 0.42, 95% confidence interval: 0.32, 0.55 and odds ratio = 0.52, 95% confidence interval: 0.39, 0.69, for men and women, respectively) followed by medication and supplementation (odds ratio = 1.68, 95% confidence interval: 1.29, 2.18 and odds ratio = 1.63, 95% CI 1.23, 2.16, respectively). Other lifestyles that were associated with colon cancer were the Western lifestyle, the lifestyle characterized by large body size, and the one characterized by calcium and low-fat dairy. Different lifestyle patterns appear to have age- and tumor site-specific associations.

Hormone replacement therapy and improved survival among postmenopausal women diagnosed with colon cancer (USA).

OBJECTIVES: Hormone replacement therapy (HRT) has been inversely associated with colon cancer incidence in several epidemiologic studies. In this study we used data from a population-based incident case-control study of colon cancer to evaluate the role of HRT use in survival after diagnosis with colon cancer. METHODS: Data from 815 postmenopausal women living in Utah, California, and Minnesota diagnosed between 1 September 1991 and 30 September 1994 were used to examine associations between HRT and survival. RESULTS: After adjusting for age at time of diagnosis, stage of disease at time of diagnosis, study center, and body mass index (BMI), we observed that women who had ever used HRT had a 30% lesser probability of dying of any cause and a 40% lower probability of dying from colon cancer specifically during the follow-up period. Further evaluation by years of HRT use showed that those who had used HRT for 4 or more years had the lowest risk of dying of colon cancer (hazard rate ratio 0.5, 95% confidence interval 0.3-0.9). Evaluation of other lifestyle variables with HRT use did not show significant confounding or effect modification. CONCLUSIONS: These findings suggest that HRT use may improve short-term survival after diagnosis with colon cancer; there is no suggestion that HRT use is detrimental to survival.

Factors associated with weight gain in women after diagnosis of breast cancer. Women's Healthy Eating and Living Study Group.

OBJECTIVE: To identify the factors associated with weight gain after diagnosis of breast cancer in a heterogeneous population of women. DESIGN: Descriptive cross-sectional study. SUBJECTS: 1,116 patients who had been diagnosed with stage I, stage II, or stage IIIA primary, operable breast cancer within the previous 4 years. Patients were recruited during enrollment into a diet intervention trial to reduce risk for breast cancer recurrence. Analysis Demographic data, weight history, and physical activity information obtained by questionnaire and medical information obtained by chart review; dietary assessment based on four 24-hour dietary recalls collected by telephone. Associations between weight change after the diagnosis of breast cancer and prediction variables were examined using univariate and multiple linear regression analyses. RESULTS: Overall, 60% of the subjects reported weight gain, 26% reported weight loss, and 14% reported no change in weight after the diagnosis of breast cancer. The overall mean weight change was a gain of 2.7 kg (6 lb). Factors positively and independently associated with weight gain were time since diagnosis of breast cancer, adjuvant chemotherapy, African-American ethnicity, current energy intake, and postmenopausal status at time of study entry. Factors inversely and independently associated with weight gain were prediagnosis body mass index, age at diagnosis, education level, and exercise index score. APPLICATIONS: Higher energy intake and lower level of physical activity are independently associated with increased risk for weight gain after the diagnosis of breast cancer. Strategies to modify these behaviors are likely to influence the long-term pattern of weight change.