Reproductive factors, exogenous hormone use and bladder cancer risk in a prospective study.

Sex is a consistent predictor of bladder cancer: men experience 2-4-fold higher age-adjusted rates than women in the U.S. and Europe.

Diet and sex hormones in boys: findings from the dietary intervention study in children.

Context: Diet reportedly alters serum sex hormone concentrations in adults, but little is known about the influence of diet during puberty on these hormones.

Objective: We aimed to determine whether an intervention to lower fat intake during adolescence alters serum sex hormone concentrations and progression through puberty.

Design: In 1990-1997, we conducted an ancillary study to the Dietary Intervention Study in Children, a multicenter, randomized, controlled clinical trial to test the safety and efficacy of a cholesterol-lowering dietary intervention in children.

Intake of the major carotenoids and the risk of epithelial ovarian cancer in a pooled analysis of 10 cohort studies.

Carotenoids, found in fruits and vegetables, have the potential to protect against cancer because of their properties, including their functions as precursors to vitamin A and as antioxidants. We examined the associations between intakes of alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin and lycopene and the risk of invasive epithelial ovarian cancer. The primary data from 10 prospective cohort studies in North America and Europe were analyzed and then pooled.

A prospective study of dietary alpha-linolenic acid and the risk of prostate cancer (United States).

Background: Alpha-linolenic acid (ALA) is the most common omega-3 fatty acid in the Western diet. The relation of dietary intake of ALA to prostate cancer risk remains unresolved.

Objective: We prospectively evaluated total ALA and ALA from specific food sources including animal, fish, and plant sources in relation to prostate cancer risk.

High dry bean intake and reduced risk of advanced colorectal adenoma recurrence among participants in the polyp prevention trial.

Adequate fruit and vegetable intake was suggested to protect against colorectal cancer and colorectal adenomas; however, several recent prospective studies reported no association. We examined the association between fruits and vegetables and adenomatous polyp recurrence in the Polyp Prevention Trial (PPT). The PPT was a low-fat, high-fiber, high-fruit, and vegetable dietary intervention trial of adenoma recurrence, in which there were no differences in the rate of adenoma recurrence in participants in the intervention and control arms of the trial.

A comparison of two dietary instruments for evaluating the fat-breast cancer relationship.

Background: Previous research suggests food diaries may be more efficient than food frequency questionnaires (FFQ) in detecting a dietary fat-breast cancer relationship. We assessed this further using 4 day food records (FRs) and FFQs in a large sample.

Methods: Participants were from the non-intervention group of the dietary modification component of the Women's Health Initiative Clinical Trial: 603 breast cancer cases and 1206 controls matched on age, clinic, and length of follow-up.

Methods for pooling results of epidemiologic studies: the Pooling Project of Prospective Studies of Diet and Cancer.

With the growing number of epidemiologic publications on the relation between dietary factors and cancer risk, pooled analyses that summarize results from multiple studies are becoming more common. Here, the authors describe the methods being used to summarize data on diet-cancer associations within the ongoing Pooling Project of Prospective Studies of Diet and Cancer, begun in 1991. In the Pooling Project, the primary data from prospective cohort studies meeting prespecified inclusion criteria are analyzed using standardized criteria for modeling of exposure, confounding, and outcome variables.

Inflammatory cytokine gene polymorphisms, nonsteroidal anti-inflammatory drug use, and risk of adenoma polyp recurrence in the polyp prevention trial.

Background: Pro- and anti-inflammatory cytokine genes may be important in the maintenance and progression of colorectal cancer. It is possible that single-nucleotide polymorphisms in inflammatory genes may play a role in chronic colonic inflammation and development of colorectal adenomas. Furthermore, common variants in cytokine genes may modify the anti-inflammatory effect of nonsteroidal anti-inflammatory drugs (NSAIDs) in the prevention of colorectal cancer.

Methodology for adding glycemic load values to the National Cancer Institute Diet History Questionnaire database.

Background: A growing interest exists in using glycemic index and glycemic load as potentially important exposures in investigations of risk for a variety of chronic diseases.

Objective: We added values for glycemic index and glycemic load to the nutrient database of a commonly used dietary assessment instrument, the Diet History Questionnaire (DHQ).

Design: The nutrient database for the DHQ is based on 4,200 individual foods reported by adults in the 1994-1996 US Department of Agriculture Continuing Survey of Food Intakes by Individuals (CSFII).

Alcohol intake and ovarian cancer risk: a pooled analysis of 10 cohort studies.

Alcohol has been hypothesized to promote ovarian carcinogenesis by its potential to increase circulating levels of estrogen and other hormones; through its oxidation byproduct, acetaldehyde, which may act as a cocarcinogen; and by depletion of folate and other nutrients. Case-control and cohort studies have reported conflicting results relating alcohol intake to ovarian cancer risk. We conducted a pooled analysis of the primary data from ten prospective cohort studies.

Association of energy intake and energy balance with postmenopausal breast cancer in the prostate, lung, colorectal, and ovarian cancer screening trial.

Energy restriction remains one of the most effective ways known to prevent breast cancer in animal models. However, energy intake has not been consistently associated with risk of breast cancer in humans. In a prospective study, we assessed whether energy intake, body size, and physical activity each independently influence breast cancer risk in postmenopausal women and estimated the joint effect of combinations of these individual factors.

High serum selenium and reduced risk of advanced colorectal adenoma in a colorectal cancer early detection program.

Background: Epidemiologic and animal studies suggest that selenium may reduce risk of colorectal cancer. However, the epidemiologic data is mainly from relatively small investigations, limiting their interpretation. Although substantial evidence suggests that smoking is a strong effect modifier for other antioxidative nutrients, little is known about smoking-selenium interactions in colorectal tumors.

Physical activity and the risk of colon cancer among women: a prospective cohort study (United States).

Physical activity has frequently been reported to decrease the risk of colon cancer in men, but data on the relation of physical activity to colon cancer risk in women have generally been less consistent. To further investigate the relationship of physical activity with colon cancer risk in women, we studied a cohort of 31,783 US women participating in the Breast Cancer Detection Demonstration Project Follow-up Study. Information on daily physical activity over the past year was ascertained using a self-administered questionnaire at study baseline.

A pooled analysis of 12 cohort studies of dietary fat, cholesterol and egg intake and ovarian cancer.

Fat and cholesterol are theorized to promote ovarian carcinogenesis by increasing circulating estrogen levels. Although case-control studies have reported positive associations between total and saturated fat intake and ovarian cancer risk, two cohort studies have observed null associations. Dietary cholesterol and eggs have been positively associated with ovarian cancer risk.

Fiber, sex, and colorectal adenoma: results of a pooled analysis.

Background: Evidence for an association between dietary fiber and colorectal neoplasia has been equivocal, and some data suggest that there may be sex differences in response to fiber.

Objective: We sought to determine whether fiber affects colorectal adenoma recurrence differently in men and women by combining the study populations of 2 large clinical intervention trials: the Wheat Bran Fiber Trial and the Polyp Prevention Trial.

Design: Data from 3209 participants combined from 2 trials were analyzed with logistic regression models to examine the effect of a dietary intervention on colorectal adenoma recurrence in the pooled population as a whole and by sex.

Dietary fiber intake and risk of colorectal cancer: a pooled analysis of prospective cohort studies.

Context: Inconsistent findings from observational studies have continued the controversy over the effects of dietary fiber on colorectal cancer.

Objective: To evaluate the association between dietary fiber intake and risk of colorectal cancer.

Design, Setting, And Participants: From 13 prospective cohort studies included in the Pooling Project of Prospective Studies of Diet and Cancer, 725,628 men and women were followed up for 6 to 20 years across studies.

Empirically derived dietary patterns and risk of postmenopausal breast cancer in a large prospective cohort study.

Background: Inconsistent associations have been reported between diet and breast cancer.

Objective: We prospectively examined the association between dietary patterns and postmenopausal breast cancer risk in a US-wide cohort study.

Design: Data were analyzed from 40 559 women who completed a self-administered 61-item Block food-frequency questionnaire in the Breast Cancer Detection Demonstration Project, 1987-1998; 1868 of those women developed breast cancer.

Does nonsteroidal anti-inflammatory drug use modify the effect of a low-fat, high-fiber diet on recurrence of colorectal adenomas?

The Polyp Prevention Trial was designed to evaluate the effects of a high-fiber (18 g/1,000 kcal), high-fruit and -vegetable (3.5 servings/1,000 kcal), low-fat (20% energy) diet on recurrence of adenomatous polyps. Participants > or =35 years of age, with histologically confirmed colorectal adenoma(s) removed in the prior 6 months, were randomized to the intervention or control group.

The association between cigarette smoking and colorectal polyp recurrence (United States).

Objective: Although evidence exists linking smoking to precancerous colorectal adenomatous polyps, few studies have examined the association between cigarette smoking and recurrence of colorectal polyps. This association was investigated prospectively with data from the Polyp Prevention Trial.

Methods: Cigarette smoking data were collected through baseline interviews.

Fruits and vegetables and ovarian cancer risk in a pooled analysis of 12 cohort studies.

Because fruits and vegetables are rich in bioactive compounds with potential cancer-preventive actions, increased consumption may reduce the risk of ovarian cancer. Evidence on the association between fruit and vegetable intake and ovarian cancer risk has not been consistent. We analyzed and pooled the primary data from 12 prospective studies in North America and Europe.

Endometrial carcinoma risks among menopausal estrogen plus progestin and unopposed estrogen users in a cohort of postmenopausal women.

Background: Because unopposed estrogen substantially increases endometrial carcinoma risk, estrogen plus progestin is one menopausal hormone therapy formulation for women who have not had a hysterectomy. However, endometrial carcinoma risks among estrogen plus progestin users and among former unopposed estrogen users are not firmly established.

Methods: We evaluated endometrial carcinoma risks associated with estrogen plus progestin and unopposed estrogen therapies in 30,379 postmenopausal Breast Cancer Detection Demonstration Project follow-up study participants.

Colonoscopic screening of average-risk women for colorectal neoplasia.

Background: Veterans Affairs (VA) Cooperative Study 380 showed that some advanced colorectal neoplasias (i.e., adenomas at least 1 cm in diameter, villous adenomas, adenomas with high-grade dysplasia, or cancer) in men would be missed with the use of flexible sigmoidoscopy but detected by colonoscopy.

Gene-specific methylation and subsequent risk of colorectal adenomas among participants of the polyp prevention trial.

Hypermethylation of tumor suppressor and other regulatory genes is thought to play an important role in colorectal neoplasia and tumorigenesis. This study examined the association between gene methylation status in baseline adenomas and subsequent adenoma recurrence in a randomized dietary intervention study, the Polyp Prevention Trial. The methylation status of four genes [CDKN2A (p16), PTGS2 (COX2), ESR1 (ER-alpha), and PGR(PR)] was determined by MethyLight in 284 baseline adenomas from 196 trial participants.