Association of NAT and GST polymorphisms with non-Hodgkin's lymphoma: a population-based case-control study

Several chemicals have been associated with risk of non-Hodgkin's lymphoma (NHL), many of which are substrates for N-acetyltransferase (NAT) and glutathione S-transferase (GST) enzymes. We investigated the association between polymorphisms in genes coding for these enzymes and NHL risk in a population-based study (389 cases and 535 controls). NAT1 slow genotype was associated with a slightly increased risk in women [odds ratios (OR) = 1.4; 95% confidence interval (CI) = 0.9-2.3], but not in men. NAT2 slow genotype was not associated with risk in either sex. The two slow genotypes of NAT1 and NAT2 combined were associated with a minor increase of risk in women (OR = 1.4; 0.8-2.4). There was no association with the GSTM1 or GSTT1 null genotype in either sex, irrespective of histological subtypes. Individuals with GSTP1 Val homozygotes had non-significant excessive risk of marginal zone lymphoma (OR = 1.8; 0.6-5.1) and 'other' B-cell NHLs (OR = 1.6; 0.7-3.6), but lower risk of diffuse large B-cell lymphoma (OR = 0.2; 0.1-0.96). Risk did not elevate with an increasing number of high-risk GST alleles in either sex. In summary, although NAT1, NAT2, GSTM1, GSTT1, or GSTP1 polymorphisms do not appear to be associated with NHL risk overall, there might be gender-specific and subtype-specific associations that require confirmation.

Longitudinal Associations of Age, Anthropometric and Lifestyle Factors with Serum Total Insulin-Like Growth Factor-I and IGF Binding Protein-3 Levels in Black and White Men: the CARDIA Male Hormone Study

Although several studies have assessed cross-sectional correlates of serum insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3), there are no longitudinal studies of the correlates of long-term changes in these measures. We examined the 8-year longitudinal associations of age, body mass index (BMI), waist circumference, physical activity, number of cigarettes smoked per day, and alcohol intake with serum total IGF-I and IGFBP-3 concentrations in 622 Black and 796 White male participants of the Coronary Artery Risk Development in Young Adults Study who were ages 20 to 34 years at the time of the first IGF measurement. In generalized estimating equation analyses, IGF-I decreased by 5.6 and 5.9 ng/mL per year increase in age for Black and White men, respectively (P< 0.0001), and there was an age-related decline in IGFBP-3 that was stronger in Whites (P < 0.0001) than Blacks (P = 0.21). Average IGF-I (β = −17.51 ng/mL) and IGFBP-3 (β = −355.4 ng/mL) levels across all three exams were lower in Blacks than Whites (P < 0.0001). Increased BMI was associated with decreased IGF-I (P < 0.0002), but was not associated with IGFBP-3. There were no meaningful associations with waist circumference. Increased physical activity was associated with a decrease in IGFBP-3 (P < 0.05), but was not associated with IGF-I. In White men, there were weak inverse associations between the number of cigarettes smoked per day with IGF-I (P=0.15) and with IGFBP-3 (P = 0.19), and in Black men, increased alcohol intake was associated with a decrease in IGF-I (P = 0.011). In conclusion, these results support an age-related decline and Black-White difference in serum IGF-I and IGFBP-3 levels. Importantly, they suggest that IGF-I and/or IGFBP-3 levels could be influenced by changes in BMI, and perhaps by physical activity, alcohol intake, and cigarette smoking.

Longitudinal associations of age, anthropometric and lifestyle factors with serum total insulin-like growth factor-I and IGF binding protein-3 levels in Black and White men: the CARDIA Male Hormone Study

Although several studies have assessed cross-sectional correlates of serum insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3), there are no longitudinal studies of the correlates of long-term changes in these measures. We examined the 8-year longitudinal associations of age, body mass index (BMI), waist circumference, physical activity, number of cigarettes smoked per day, and alcohol intake with serum total IGF-I and IGFBP-3 concentrations in 622 Black and 796 White male participants of the Coronary Artery Risk Development in Young Adults Study who were ages 20 to 34 years at the time of the first IGF measurement. In generalized estimating equation analyses, IGF-I decreased by 5.6 and 5.9 ng/mL per year increase in age for Black and White men, respectively (P< 0.0001), and there was an age-related decline in IGFBP-3 that was stronger in Whites (P < 0.0001) than Blacks (P = 0.21). Average IGF-I (beta = -17.51 ng/mL) and IGFBP-3 (beta = -355.4 ng/mL) levels across all three exams were lower in Blacks than Whites (P < 0.0001). Increased BMI was associated with decreased IGF-I (P < 0.0002), but was not associated with IGFBP-3. There were no meaningful associations with waist circumference. Increased physical activity was associated with a decrease in IGFBP-3 (P < 0.05), but was not associated with IGF-I. In White men, there were weak inverse associations between the number of cigarettes smoked per day with IGF-I (P=0.15) and with IGFBP-3 (P = 0.19), and in Black men, increased alcohol intake was associated with a decrease in IGF-I (P = 0.011). In conclusion, these results support an age-related decline and Black-White difference in serum IGF-I and IGFBP-3 levels. Importantly, they suggest that IGF-I and/or IGFBP-3 levels could be influenced by changes in BMI, and perhaps by physical activity, alcohol intake, and cigarette smoking.

Insulin-like growth factor-1, insulin-like growth factor binding protein-3, and cardiovascular disease risk factors in young black men and white men: the CARDIA Male Hormone Study

Cross-sectional studies have found associations between components of the insulin-like growth factor (IGF) system and hypertension, total cholesterol, and low density lipoprotein cholesterol. Using partial correlation analysis and longitudinal analysis of data collected at the year 2, year 7, and year 10 examinations, the authors assessed the associations of IGF-1 and IGF binding protein-3 (IGFBP-3) with cardiovascular disease risk factors in 544 Black and 747 White male participants in the Coronary Artery Risk Development in Young Adults (CARDIA) Male Hormone Study who were aged 20-34 years at year 2 (1987-1988). There were no consistent independent associations with blood pressure. Cross-sectionally, there were some inverse associations between IGF-1 and lipid levels in White men (strongest r = -0.095 (p = 0.02) for total cholesterol at year 7) and positive associations between IGFBP-3 and lipid levels in Black and White men (for log(triglycerides), r = 0.072-0.136). Longitudinally, a 1,000-ng/ml increase in IGFBP-3 was associated with 3.7-mg/dl and 2.6-mg/dl higher total cholesterol levels and 2.6-mg/dl and 1.7-mg/dl higher low density lipoprotein cholesterol levels in Black men and White men (p < 0.05), respectively. These findings do not support a strong link between IGF-1 and IGFBP-3 and blood pressure, but they do support the possibility of important relations between IGFBP-3 and lipid levels in young adult men.

Results of mujeres felices por ser saludables: a dietary/breast heafth randomized chnicail trial for latino women

BACKGROUND

Data are limited on the efficacy of health-focused interventions for young, low-acculturated Latino women. Because breast cancer is the most commonly diagnosed cancer and the most common cause of cancer mortality in this population, combined interventions that address both early detection and dietary patterns could help reduce both morbidity and mortality associated with breast cancer in this underserved population.

PURPOSE

Mujeres Felices por ser Saludables was randomized intervention study designed to assess the efficacy of an 8-month combined dietary and breast health intervention to reduce fat and increase fiber intake as well as to increase the frequency and proficiency of breast self-examination (BSE) and reduce anxiety related to BSE among Latinas.

METHODS

Blocked randomization in blocks of 6 was used to randomize 256 20- to 40-year-old Latinas to the intervention (n = 127) or control group (n = 129). The intervention group attended an 8-month multicomponent education program designed specifically for low-acculturated Latinas. The control group received mailed health education material on a schedule comparable to the intervention. A total of 195 women (76.2%) completed both the baseline and 8-month follow-up interviews.

RESULTS

The intervention and control groups were similar on baseline sociodemographic characteristics. At the 8-month follow up, the intervention group reported lower dietary fat (P < .001) and higher fiber intake (p = .06); a higher proportion reported practicing BSE at the recommended interval (p < .001) and showed improved BSE proficiency (p < .001) compared to the control group. BSE-related anxiety was low for both groups at baseline, and no difference in reduction was observed.

CONCLUSIONS

This project provides a successful model for achieving dietary change and improving breast health behavior in young, low-acculturated Latinas.

Changes in Diet During Adult Life and Risk of Colorectal Adenomas

To evaluate the associations of changes in diet during adult life with adenoma risk, data from a case-control study of 146 colorectal adenomas and 226 controls were analyzed. Dietary habits during the year before sigmoidoscopy and when subjects were 30 yr old were collected using a food-frequency questionnaire. Change in frequency of consumption during adulthood was calculated by subtracting frequency of consumption of specific foods or food groups at age 30 yr from frequency of consumption during the previous year (recent consumption). Associations with changes in frequency of consumption were estimated by odds ratios (ORs) and 95% confidence intervals (CIs). There was no association for foods or food groups consumed at age 30 yr. For recent consumption, more frequent consumption of red meat, breakfast sausage, and pork chops/ham steaks and less frequent consumption of fish, chicken/turkey, and vegetables were related to a higher risk. Compared with individuals with the highest reduction in consumption since age 30 yr, risks were higher for those with smallest reduction in red meat intake (OR = 2.8; CI = 1.1-7.3), particularly for hamburgers/cheeseburgers (OR = 2.8; CI = 1.2-6.8) and pork chops/ham steaks (OR = 3.7; CI = 1.6-8.7). In contrast, individuals in the highest quartile of increased consumption of fish (OR = 0.6; CI = 0.3-1.1) and vegetables (OR = 0.5; CI = 0.3-1.1) had a lower risk compared with those with minimal increase in consumption. In conclusion, irrespective of frequency of consumption at age 30 yr, a greater reduction in consumption of red meat and a larger increase in consumption of vegetables since age 30 yr were associated with a decreased risk of colorectal adenomas later in life.

Agricultural pesticide use, familial cancer, and risk of non-Hodgkin lymphoma

To investigate whether the association between agricultural pesticide use and the risk of non-Hodgkin's lymphoma (NHL) is modified by a family history of hematopoietic cancer, including leukemia, myeloma, and lymphoma, we analyzed pooled data on white men from three population-based, case-control studies of NHL conducted in Iowa/Minnesota, Kansas, and Nebraska. Information on the agricultural use of insecticides, fungicides, and herbicides; a family history of cancer; and other risk factors was obtained by interviewing 973 cases and 2,853 controls or, if deceased, their next-of-kin (37% of cases, 43% of controls). The NHL risk was estimated by odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for age, state of residence, type of respondent, and use of hair dye. Compared to men with no family history of cancer, the ORs (95% CIs) of NHL was 1.5 (1.3-1.8) for men with a family history of nonhematopoietic cancer, and 2.7 (1.9-3.7) for those with a history of hematopoietic cancer among first-degree relatives. This positive association was noted for each group of NHL defined according to the Working Formulation, and was most pronounced for small lymphocytic NHL. Among direct respondents, farmers who used pesticides and had a positive family history of cancer or hematopoietic cancer were not at elevated risk of NHL, compared to nonfarmers who had no family cancer history. However, among proxy respondents, ORs were elevated for farmers who had a positive family history of hematopoietic cancer and used animal insecticides (OR = 4.6; 1.9-11.2), crop insecticides (OR = 4.7; 1.6-13.4), or herbicides (OR = 4.9; 1.7-14.2), although the interaction of family history of cancer and agricultural pesticide use was not statistically significant. In summary, the joint effects of the family cancer history and pesticide use were limited to proxy respondents with wide CIs and, thus, provide little evidence that a family history of cancer modifies the association of agricultural exposures with NHL.

Agricultural Pesticide Use, Familial Cancer, and Risk of Non-Hodgkin Lymphoma

To investigate whether the association between agricultural pesticide use and the risk of non-Hodgkin's lymphoma (NHL) is modified by a family history of hematopoietic cancer, including leukemia, myeloma, and lymphoma, we analyzed pooled data on white men from three population-based, case-control studies of NHL conducted in Iowa/Minnesota, Kansas, and Nebraska. Information on the agricultural use of insecticides, fungicides, and herbicides; a family history of cancer; and other risk factors was obtained by interviewing 973 cases and 2,853 controls or, if deceased, their next-of-kin (37% of cases, 43% of controls). The NHL risk was estimated by odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for age, state of residence, type of respondent, and use of hair dye. Compared to men with no family history of cancer, the ORs (95% CIs) of NHL was 1.5 (1.3–1.8) for men with a family history of nonhematopoietic cancer, and 2.7 (1.9–3.7) for those with a history of hematopoietic cancer among first-degree relatives. This positive association was noted for each group of NHL defined according to the Working Formulation, and was most pronounced for small lymphocytic NHL. Among direct respondents, farmers who used pesticides and had a positive family history of cancer or hematopoietic cancer were not at elevated risk of NHL, compared to nonfarmers who had no family cancer history. However, among proxy respondents, ORs were elevated for farmers who had a positive family history of hematopoietic cancer and used animal insecticides (OR = 4.6; 1.9–11.2), crop insecticides (OR = 4.7; 1.6–13.4), or herbicides (OR = 4.9; 1.7–14.2), although the interaction of family history of cancer and agricultural pesticide use was not statistically significant. In summary, the joint effects of the family cancer history and pesticide use were limited to proxy respondents with wide CIs and, thus, provide little evidence that a family history of cancer modifies the association of agricultural exposures with NHL.

Physical inactivity and percent breast density among Hispanic women

Results of epidemiologic studies suggest an inverse association between breast cancer risk and physical activity; this is one of the few modifiable breast cancer risk factors identified to date. However, only 2 previous studies assessed the association between physical activity and the extent of mammographically-detected fibroglandular breast density, a marker of breast cancer risk. Moreover, there has been no study of physical inactivity and percent breast density, nor a study of this relationship in Hispanic women, who are less physically active than non-Hispanic whites. In the Chicago Breast Health Project, we collected information on sociodemographic, reproductive, medical and lifestyle factors and percent breast density, assessed quantitatively using full-field digital mammography, from 294 Hispanic women. In our study, we examined the independent associations of hours per day of physical inactivity with percent breast density using multivariate linear regression analysis adjusting for age, education, body mass index, parity, menopausal status, use of hormone replacement therapy and smoking status. Overall, the mean percent breast density was low (i.e., 17.7%) and ranged from 1.9% to 54.6%. There was no difference in percent breast density for women who reported 1.5-3.0 hr of physical inactivity per day compared to women who reported 0-1 hr per day (beta = -0.08, p = 0.95), but percent density was marginally significantly higher for women who were reported at least 3.5 hr per day of physical inactivity (beta = 3.18, p = 0.056). Results were similar, albeit less statistically significant, in analyses of pre/perimenopausal and postmenopausal women separately. These results support the need for further research investigating the effect of physical activity on breast cancer risk.

Cigarette smoking and colorectal carcinoma mortality in a cohort with long-term follow-up

BACKGROUND

Evidence suggests that colorectal carcinoma (CRC) may be a tobacco-associated malignancy.

METHODS

In the current study, the authors examined the association between cigarette smoking and CRC mortality in the Chicago Heart Association Detection Project in Industry study, a cohort of 39,299 men and women with an average of 26 years of follow-up. To assess whether the association was stronger in participants with a potentially long history of smoking, the authors also stratified the analysis using a baseline age > or = 50 years versus < 50 years.

RESULTS

Using multivariate Cox regression analysis, there was a marginally significant trend (P = 0.06) for men and women combined between smoking and CRC mortality. In the age-stratified analysis in the older participant group, there was no apparent association for men, women, or men and women combined. In the younger participant group, there appeared to be dose-response relations for women and for men and women combined (P value for trend = 0.008 and 0.03, respectively) between smoking and CRC mortality. The relative risk for women who smoked >20 cigarettes/day compared with never smokers was 2.49 (95% confidence interval [95% CI], 0.87-7.12), and was 1.87 for men and women combined (95% CI, 1.08-3.22).

CONCLUSIONS

The results of the current study support an association between cigarette smoking and CRC mortality, particularly in women age < 50 years.

The effects of a low-fat/high-fiber diet on sex hormone levels and menstrual cycling in premenopausal women: a 12-month randomized trial (the diet and hormone study)

BACKGROUND

Reduction of cumulative exposure to endogenous ovarian steroid hormones is a postulated method for reducing the risk of carcinoma of the breast and other malignancies. Although there are data from trials evaluating the effect of low-fat and high-fiber diets on sex hormone levels in premenopausal women, to the authors' knowledge none of these trials has combined a relatively large number of participants, follow-up of > 2-3 months, parallel controls receiving a usual diet, and careful timing of blood sampling within the menstrual cycle.

METHODS

A total of 213 healthy women, ages 20-40 years, were randomly assigned to follow their usual diet or to adopt an isocaloric diet with goals of 20% calories as fat, total fiber of 25 g/day, and at least 8 fruit or vegetable servings per day. Serum levels of total estradiol (E2), sex hormone-binding globulin (SHBG), non-SHBG-bound estradiol (NSBE2), SHBG, and progesterone were evaluated during a menstrual cycle at baseline, and at 4 cycles (C4) and 12 cycles (C12) after the start of the intervention. Serum was collected during each test cycle 7-9 days after the detection of an luteinizing hormone peak in the urine. One hundred eighty-nine women provided serum at C4 and 176 women at C12.

RESULTS

Serum E2 decreased by an average of 7.5% or 7.8 pg/mL (95% confidence interval [95% CI], -16.0-0.04) at C12 in the intervention group, versus a decrease of 0.9% or 0.9 pg/mL (95% CI, -9.5-7.7) in the control group (the P value for the difference between the treatment groups was 0.25). Results for NSBE2 were very similar to those for total estradiol. There were no material effects found to result from intervention with regard to SHBG or progesterone. The results did not differ by baseline age, body mass index, or baseline hormone level above or below the median, and were not likely to be affected by weight change, which amounted to a mean loss of only 0.23 kg in the diet group versus a gain of 0.17 kg in the control group. The decrease in serum E2 associated with intervention was not greater when subjects were stratified by self-reported adherence to the dietary goals.

CONCLUSIONS

The results of the current study suggest that the effects of this isocaloric low-fat, high-fiber diet pattern on circulating ovarian steroids were modest or nonexistent. However, the observed 7.5% reduction in estradiol could have biologic significance if it persisted over many years. Moreover, underestimation of the true dietary effect could have occurred because of incomplete adherence to assigned diets. Weight loss and weight control through midlife could be a more effective and feasible approach to dietary intervention in reducing the risk of breast carcinoma.

Associations of breast cancer risk factors with breast density in Hispanic women

Although there has been much research on the factors associated with breast density, most studies did not include Hispanic women or relied on semiquantitative methods of assessing density. Using data from the Chicago Breast Health Project, which targeted Hispanic women and assessed density quantitatively using full-field digital mammography, we assessed cross-sectional associations of breast cancer risk factors with percentage of breast density. Between November 2000 and June 2002, 296 Hispanic women recruited from three community health centers in Chicago, Illinois completed a health and lifestyle questionnaire, had their height and weight measured, and underwent screening mammography. The average percentage of total breast area occupied by fibroglandular tissue was computed from each mammographic view. Associations of breast cancer risk factors with percentage of breast density were assessed using multivariate linear regression analyses. Overall, the mean percentage of breast density was 17.6%. In multivariate analysis, older age was associated with lower density (P = 0.03), and density was lower among postmenopausal than premenopausal women (beta = 5.2%; P = 0.002). Body mass index was significantly inversely related to percentage of breast density (P < 0.00001). Women currently taking hormone replacement therapy had a higher percentage of breast density (beta = 3.3%; P = 0.03). In premenopausal women, cigarette smokers had a marginally higher percentage of density (beta = 6.23%; P = 0.06) compared with nonsmokers, but there was no relationship for postmenopausal women. Other breast cancer risk factors were not associated with density. In summary, breast density was strongly and inversely associated with age, body mass index, and menopausal status, and positively associated with hormone replacement therapy use and cigarette smoking. Additional research focusing on relationships of other, potentially modifiable, factors with the extent of breast density is warranted to better understand the interindividual variability in density among Hispanic women.

Mujeres felices por ser saludables: a breast cancer risk reduction program for Latino women

BACKGROUND

Breast cancer is the most commonly diagnosed cancer and the most common cause of cancer mortality among Latino women. Several behavioral factors such as early detection and dietary practices could help decrease morbidity and mortality associated with breast cancer in this population. Unfortunately, there are few data regarding the efficacy of health-related interventions for young Latino women.

METHODS

Mujeres Felices por ser Saludables is a randomized intervention project designed to assess breast cancer risk reduction behavior among Latino women ages 20-40 years. The primary objectives of the project were to determine whether an 8-month integrated dietary/breast health intervention could lead to a greater reduction in dietary fat, increase in dietary fiber, increase in the frequency and proficiency of breast self examination (BSE), and reduction in anxiety related to BSE compared to controls. Herein we describe the overall design of the project and present baseline characteristics of the 256 randomized women.

RESULTS

Our results suggest that the average daily intake of dietary fat (percentage of total energy) was slightly below 30% (percentage of total energy) among the women randomized. While over half of these women reported that they practice BSE, and few reported anxiety related to BSE, less than 27% of women were proficient in the recommended BSE technique.

CONCLUSIONS

There are few data on the dietary and breast health behaviors of young low-acculturated Latino women. This study documents the feasibility of recruiting, randomizing, and obtaining both baseline dietary and breast health data on this unique and underserved population.

Reducing disparities in breast cancer survival: a Columbia University and Avon Breast Cancer Research and Care Network Symposium

On November 8th, 2001, faculty from Universities, government and non-profit community organizations met to determine how, separately and together, they could address disparities in survival of women with breast cancer in the diverse patient populations served by their institutions. Studies and initiatives directed at increasing access had to date met modest success. The day was divided into three sections, defining the issues, model programs, government initiatives and finally potential collaborations. By publishing these proceedings, interested readers will be aware of the ongoing programs and studies and can contact the investigators for more information. The Avon Foundation funded this symposium to bring together interested investigators to share programmatic experiences, data and innovative approaches to the problem.

Interaction of dietary folate intake, alcohol, and risk of hormone receptor-defined breast cancer in a prospective study of postmenopausal women

Alcohol intake is an established risk factor for breast cancer, but the underlying mechanism remains unknown. Four recent studies have described interactions of alcohol and low folate intake. We examined this interaction on the risk of postmenopausal breast cancer stratified by tumor receptor status for estrogen (ER) and progesterone (PR). The Iowa Women's Health Study is a prospective cohort study of 34,393 at-risk women. Alcohol use and folate intake from diet and supplements were estimated at baseline in 1986 through a semiquantitative food frequency questionnaire. Through 1999, 1,875 cases of breast cancer were identified through linkage to the Iowa Surveillance, Epidemiology, and End Results registry. Compared with nondrinkers with folate intakes above the 50(th) percentile, women with low folate and high alcohol were at 1.43-fold greater risk (1.02-2.02). When stratified by tumor receptor status for ER or PR, the risks for low folate/high alcohol were 2.1 (1.18-3.85), 1.0 (0.76-1.42), 1.2 (0.88-1.70), and 1.2 (0.69-2.02) for ER-, ER+, PR+, and PR- tumors, respectively. Because the results were limited primarily to ER- tumors, one plausible interpretation of these data is that alcohol influences breast cancer through its metabolite, acetaldehyde, rather than through effects on ER levels and receptor-mediated pathways.

Serum androgen concentrations in young men: a longitudinal analysis of associations with age, obesity, and race. The CARDIA male hormone study

Serum testosterone concentration appears to be higher in black men than white men, particularly at younger ages. The higher incidence of prostate cancer in blacks has been attributed, at least in part, to this difference. Other factors associated with androgen levels in men include age and obesity. However, most of the studies of adult androgen levels are limited by their cross-sectional design. We conducted longitudinal analyses (Generalized Estimating Equation) of the associations of age, body mass index (BMI), and waist circumference with total and free testosterone and sex hormone-binding globulin (SHBG) concentrations during an 8-year period and compared these hormonal factors between black (n = 483) and white (n = 695) male participants of the Coronary Artery Risk Development in Young Adults (CARDIA) Study. For men ages 24 years and older at the time of the first hormone measurement, increasing age was associated with a statistically significant decrease in serum total and free testosterone and an increase in SHBG (P < 0.05). BMI and waist circumference were inversely associated with total testosterone and SHBG, but only BMI was inversely associated with free testosterone. After adjustment for age and BMI, total testosterone was higher in blacks (0.21 ng/ml; P = 0.028) than whites, an approximately 3% difference. However, after further adjustment for waist circumference, there was no black-white difference (0.05 ng/ml; P = 0.62). These results indicate that the age-associated decrease in circulating testosterone and increase in SHBG begin during the 3rd decade of life, and that increasing obesity, particularly central obesity, is associated with decreasing total testosterone and SHBG. Results also suggest that the previously observed difference in total testosterone between black and white men could be attributed, for the most part, to racial differences in abdominal obesity.

Colorectal cancer mortality and factors related to the insulin resistance syndrome

It has been proposed that hyperinsulinemia is involved in colon carcinogenesis. An association between post-load plasma glucose (PLG) levels and risk of colorectal cancer mortality would be consistent with this hypothesis. We used data from the Chicago Heart Association Detection Project in Industry to examine the associations of nonfasting PLG and other variables related to the insulin resistance syndrome (i.e., systolic blood pressure, body mass index, uric acid, and resting heart rate) with colorectal cancer mortality. After excluding participants reporting a history of diabetes, 191 and 126 colorectal cancer deaths occurred among 20,433 men and 15,149 women, respectively. In multivariate Cox regression analysis, there was a positive relationship between PLG levels and colorectal cancer mortality for women (P for trend = 0.08) but not for men. When men and women were combined, a trend (P = 0.05) for PLG remained. Examination of clustering of insulin resistance syndrome-related risk factors revealed that men with at least 3 of 4 risk factors (i.e., in the highest quartile of the sex-specific distribution for PLG, systolic blood pressure, body mass index, or resting heart rate) had a relative risk (RR) of 1.67 [95% confidence interval (CI), 1.04-2.70] as compared with men who were not in the upper quartile for any of these factors. For women, the RR was 1.29 (95% CI, 0.70-2.37). For men and women combined, the RR was 1.50 (95% CI, 1.03-2.19). These findings provide evidence for a modest association of PLG and insulin resistance syndrome with colorectal cancer mortality and support the insulin hypothesis.

Alcohol and breast cancer: review of epidemiologic and experimental evidence and potential mechanisms

The association of alcohol consumption with increased risk for breast cancer has been a consistent finding in a majority of epidemiologic studies during the past 2 decades. Herein, we summarize information on this association from human and animal investigations, with particular reference to epidemiologic data published since 1995. increased estrogen and androgen levels in women consuming alcohol appear to be important mechanisms underlying the association. Other plausible mechanisms include enhanced mammary gland susceptibility to carcinogenesis, increased mammary carcinogen dna damage, and greater metastatic potential of breast cancer cells, processes for which the magnitude likely depends on the amount of alcohol consumed. Susceptibility to the breast cancer-enhancing effect of alcohol may also be affected by other dietary factors (such as low folate intake), lifestyle habits (such as use of hormone replacement therapy), or biological characteristics (such as tumor hormone receptor status). Additional progress in understanding alcohol's enhancing effect on breast cancer will depend on a better understanding of the interactions between alcohol and other risk factors and on additional insights into the multiple biological mechanisms involved.

Postload plasma glucose concentration and 27-year prostate cancer mortality (United States)

OBJECTIVE

Findings from epidemiologic studies on the association between diabetes and prostate cancer risk are inconsistent. However, data from at least three studies suggest that the direction and strength of this association differs according to duration of diabetes. To determine the potential effects of early-stage abnormal glucose metabolism on risk, we assessed the relationship of postload glycemia in the absence of self-reported diabetes with risk of prostate cancer mortality.

METHODS

Data from the Chicago Heart Association Detection Project in Industry were used to examine this relationship. Between 1967 and 1973 some employees of 84 Chicago area organizations underwent a health screening examination. Blood was drawn for measurement of plasma glucose concentration approximately 1 h after a 50-g oral glucose load among 20,433 men. After a mean length of follow-up of 27 years, 176 men died of prostate cancer. Cox regression was used to compute adjusted relative risks (RRs) and 95% confidence intervals (CIs).

RESULTS

After controlling for age, body mass index, heart rate, education, and race, the RRs of prostate cancer mortality for postload plasma glucose levels of 6.7-8.8, 8.9-11, and > or = 11.1 mmol/L compared to < or = 6.6 mmol/L were 1.64, 1.37, and 1.64. respectively (p for trend=0.19). The RR (95% CI) associated with a 2.2 mmol/L (1 standard deviation) higher glucose concentration was 1.1 (0.95-1.2).

CONCLUSIONS

These results provide weak evidence of an association between hyperglycemia and prostate cancer mortality.

Dietary folate intake, alcohol, and risk of breast cancer in a prospective study of postmenopausal women

Low B-vitamin intake may increase risk of breast cancer through decreased DNA repair capacity. Alcohol intake increases risk for breast cancer, with evidence from prospective studies of an interaction between alcohol and folate. We explored dietary intake of folate and other B vitamins with risk of breast cancer in a cohort study of 34,387 postmenopausal women. To measure diet, we mailed a food frequency questionnaire; we estimated nutrient intakes and categorized them into four levels: <10th, 11th-30th, 31st-50th, and >50th percentiles. Through 12 years of follow-up, we identified 1,586 cases of breast cancer in the cohort at risk. We estimated relative risks (RRs) and 95% confidence intervals (CIs) through Cox regression models adjusted for age, energy, and other risk factors. Women in the lowest 10th percentile of folate intake from diet alone were at modestly increased risk of breast cancer relative to those above the 50th percentile: RR = 1.21 (95% CI = 0.91--1.61). We examined the joint association of folate intake and alcohol use on risk of breast cancer, with the reference group defined as women with high folate (>50th percentile) and no alcohol use. The RRs of breast cancer associated with low dietary folate intake were 1.08 (95% CI = 0.78--1.49) among nondrinkers, 1.33 (95% CI = 0.86--2.05) among drinkers of < or = 4 gm per day, and 1.59 (95% CI = 1.05--2.41) among drinkers of > 4 gm per day. These results suggest that the risks of postmenopausal breast cancer may be increased among women with low intakes of folate if they consume alcohol-containing beverages.

Lack of association between the -308 polymorphism of the tumor necrosis factor-alpha gene and the insulin resistance syndrome

BACKGROUND

Previous studies have demonstrated a role for tumor necrosis factor-alpha (TNF-alpha) in insulin resistance. A polymorphic variant of the TNF-alpha gene, the TNF2 allele, which is a guanine to adenine polymorphism at position -308 in the TNF-alpha promoter, is associated with higher basal and inducible promoter activity. The present study examined whether the TNF2 allele was associated with altered levels of different components of the insulin resistance syndrome, clustering of these components, or the 10-year change in the level of these components.

METHODS

Components of the insulin resistance syndrome included insulin resistance, as determined by fasting insulin levels, body mass index, systolic blood pressure, triglycerides, uric acid, and high density lipoprotein-cholesterol. The study population was a subsample of participants from the Coronary Artery Risk Development in (Young) Adults (CARDIA) study, which included African American and white men and women aged 18-30. The sample included 243 black women, 142 black men, 392 white women, and 386 white men. Subjects were typed at the TNF-alpha locus.

RESULTS

The frequency of the TNF2 allele was 12% in blacks and 16% in whites. Age-adjusted levels of the different components examined were not different at either baseline or year 10 in carriers of the TNF2 allele versus homozygotes for the wild-type allele, and the 10-year change in the level of different components was not different between the two genotype groups. There also was no evidence of increased clustering of components of the insulin resistance syndrome in carriers of the TNF2 allele. Moreover, there was no evidence of an association between the TNF2 allele and clustering across quartiles of BMI or quartiles of dietary fat intake (i.e., Key's score).

CONCLUSIONS

In African Americans and whites, neither the TNF2 allele nor another polymorphism in the TNF-alpha gene or a neighboring gene with which the TNF2 allele is in linkage disequilibrium is associated with differences in the level of or increased clustering of components of the insulin resistance syndrome.

Abnormal glucose metabolism and pancreatic cancer mortality

CONTEXT

Previous studies reported an increased risk of pancreatic cancer among persons with diabetes. Few data exist, however, on the association of postload plasma glucose concentration with pancreatic cancer, which could provide insight into the role of abnormal glucose metabolism in the etiology of pancreatic cancer.

OBJECTIVE

To determine the independent association between postload plasma glucose concentration and risk of pancreatic cancer mortality among persons without self-reported diabetes.

DESIGN

Prospective cohort study.

SETTING AND PARTICIPANTS

Employees of 84 Chicago-area organizations, with an average age of 40 years at baseline, were screened from 1963 to 1973 and followed up for an average of 25 years. A total of 96 men and 43 women died of pancreatic cancer among 20,475 men and 15,183 women, respectively.

MAIN OUTCOME MEASURES

Relationship of pancreatic cancer mortality with postload plasma glucose levels.

RESULTS

Compared with a postload plasma glucose level of 6.6 mmol/L (119 mg/dL) or less and after adjusting for age, race, cigarette smoking, and body mass index, the relative risks (95% confidence intervals) of pancreatic cancer mortality were 1.65 (1.05-2.60) for postload plasma glucose levels between 6.7 (120) and 8.8 (159) mmol/L (mg/dL); 1.60 (0.95-2.70) for levels between 8.9 (160) and 11.0 (199); and 2.15 (1.22-3.80) for levels of 11.1 (200) or more; P for trend=.01. An association appeared to be stronger for men than women. Estimates were only slightly lower after excluding 11 men and 2 women who died of pancreatic cancer during the first 5 years of follow-up. In men only, higher body mass index and serum uric acid concentration also were independently associated with an elevated risk of pancreatic cancer mortality.

CONCLUSION

These results suggest that factors associated with abnormal glucose metabolism may play an important role in the etiology of pancreatic cancer. JAMA. 2000;283:2552-2558

Factors associated with axillary lymph node metastasis from breast carcinoma: descriptive and predictive analyses

BACKGROUND

Although axillary lymph node metastasis is one of the most important prognostic determinants of breast carcinoma prognoses, the reasons why tumors vary in their capability to produce for axillary metastases remain unclear.

METHODS

The authors used data from the nationwide Patient Care Evaluation (PCE) survey of the American College of Surgeons to evaluate the correlations between patient/tumor characteristics and lymph node status, and to explore the use of these factors, which are all known prior to axillary dissection, in predicting lymph node status. The PCE data set contained 18,025 breast carcinoma cases diagnosed in 1990 after exclusion of women older than 79 years or with fewer than 6 lymph nodes examined.

RESULTS

In a multivariate logistic regression model, larger tumor size, young age, African American or Hispanic race, outer half tumor location, poor or moderate differentiation, aneuploidy, and infiltrating ductal histology were independently associated with a higher likelihood of one or more positive lymph nodes. Contrary to expectation, cases negative for estrogen receptor (ER) and progesterone receptor (PR) had a lower risk of positive lymph nodes when adjusted for other factors (odds ratio = 0.82; 95% confidence interval: 0.74-0.91) compared with cases positive for both receptors. This model accurately predicted lymph node status in 2 validation data sets (a 50% random sample of 1990 PCE data and 1992 data from the National Cancer Data Base), but was less accurate in a third, older data set (1983 PCE data). However, the percentage of cases (1990 validation set) with predicted probabilities less than 0.05 or greater than 0.95 were only 4.6% and <0.1%, respectively.

CONCLUSIONS

The authors concluded that 1) most variation in axillary lymph node metastatic status can be explained by routinely available data, 2) ER and PR status may be involved in the mechanism of this behavior, and 3) the difficulty of using prediction models to avert axillary dissection should not be underestimated.

Factors associated with axillary lymph node metastasis from breast carcinoma: descriptive and predictive analyses

BACKGROUND

Although axillary lymph node metastasis is one of the most important prognostic determinants of breast carcinoma prognoses, the reasons why tumors vary in their capability to produce for axillary metastases remain unclear.

METHODS

The authors used data from the nationwide Patient Care Evaluation (PCE) survey of the American College of Surgeons to evaluate the correlations between patient/tumor characteristics and lymph node status, and to explore the use of these factors, which are all known prior to axillary dissection, in predicting lymph node status. The PCE data set contained 18,025 breast carcinoma cases diagnosed in 1990 after exclusion of women older than 79 years or with fewer than 6 lymph nodes examined.

RESULTS

In a multivariate logistic regression model, larger tumor size, young age, African American or Hispanic race, outer half tumor location, poor or moderate differentiation, aneuploidy, and infiltrating ductal histology were independently associated with a higher likelihood of one or more positive lymph nodes. Contrary to expectation, cases negative for estrogen receptor (ER) and progesterone receptor (PR) had a lower risk of positive lymph nodes when adjusted for other factors (odds ratio = 0.82; 95% confidence interval: 0.74-0.91) compared with cases positive for both receptors. This model accurately predicted lymph node status in 2 validation data sets (a 50% random sample of 1990 PCE data and 1992 data from the National Cancer Data Base), but was less accurate in a third, older data set (1983 PCE data). However, the percentage of cases (1990 validation set) with predicted probabilities less than 0.05 or greater than 0.95 were only 4.6% and <0.1%, respectively.

CONCLUSIONS

The authors concluded that 1) most variation in axillary lymph node metastatic status can be explained by routinely available data, 2) ER and PR status may be involved in the mechanism of this behavior, and 3) the difficulty of using prediction models to avert axillary dissection should not be underestimated.