PubMed HealthSearch

Biomedical subjects

E R Greenberg

Publications and source records attributed to E R Greenberg.

At least 19 recordsLinked to original sources

Body size and risk of breast cancer.

The relation between body size and breast cancer remains uncertain, particularly with regard to differences between pre- and postmenopausal women. The authors examined whether height, weight, body mass index, and weight change were associated with breast cancer risk among pre- and postmenopausal women. This population-based case-control study included women aged 20-74 years (n = 6,548) who were diagnosed with invasive breast cancer during 1988-1991 in Maine, Massachusetts, New Hampshire, and Wisconsin. Similarly aged control women (n = 9,057) were selected at random from driver's license files and Health Care Financing Administration files. Height, weight, and information on other breast cancer risk factors were ascertained by telephone interview, and logistic regression was used to estimate multivariate-adjusted odds ratios and 95% confidence intervals. Among premenopausal women, the adjusted odds ratio for the upper quintile group of height relative to the lowest was 1.36 (95% confidence interval (CI) 1.05-1.76). The heaviest premenopausal women had a lower risk (odds ratio (OR) = 0.87, 95% CI 0.70-1.10). Among postmenopausal women, the adjusted odds ratios were higher for the upper quintile categories of both height (OR = 1.27, 95% CI 1.11-1.45) and weight (OR = 1.57, 95% CI 1.37-1.79). Weight gain since ages 18 and 35 years was associated with increased postmenopausal breast cancer risk, and risk was lower in women who had lost weight. These findings suggest that programs to avoid weight gain merit study as a means to reduce risk of postmenopausal breast cancer.

Adult

Feasibility of a randomized trial of a high-vegetable diet to prevent breast cancer recurrence.

Epidemiologic evidence supports the concept that diet influences risk for breast cancer and suggests that prognosis after the diagnosis of breast cancer may also be related to modifiable nutritional factors. The purpose of this study was to investigate the feasibility of a randomized trial of a high-vegetable, reduced-fat, and increased-fiber diet intervention to reduce risk for recurrence among breast cancer survivors. This major change in dietary pattern was promoted through intensive telephone counseling. Participants were 93 women who had been diagnosed with breast cancer (stages I, II, and IIIA) within the previous four years and who had completed their initial treatment. We assessed adherence to the study diet using repeated 24-hour dietary recalls at 6 and 12 months and measurement of circulating carotenoid concentrations. Six months after randomization, the intervention group had significantly increased their mean intake of vegetables (+4.6 servings/day), fruit (+0.7 servings/day), and fiber (+6.4 g/1,000 kcal) and significantly reduced their intake of dietary fat (-9.9% of energy) compared with the control group. Circulating concentrations of carotenoids also increased in the intervention group. These changes persisted at the 12-month visit. Results of this study demonstrate that telephone counseling can be a useful approach in diet intervention and that breast cancer survivors can adopt and maintain a high-vegetable, reduced-fat dietary pattern.

Biomarkers

Effects of 4 y of oral supplementation with beta-carotene on serum concentrations of retinol, tocopherol, and five carotenoids.

beta-Carotene has been studied widely as a potential cancer-preventing agent. Recent studies found that subjects who took beta-carotene supplements orally had increases in their serum concentrations of alpha-carotene and lycopene that were large (> 150% increase) and significantly greater than such increases in subjects who received placebo and that similar supplementation was associated with a decrease of approximately 37% in plasma lutein concentrations. A biologic interaction between beta-carotene and other carotenoids was suggested. We measured concentrations of retinol, alpha-tocopherol, and five carotenoids in serum specimens from a random sample of subjects enrolled in a clinical trial of the use of antioxidant vitamins in preventing colonic adenomas. We used serum specimens obtained at enrollment and after the subjects took placebo (n = 54) or 25 mg beta-carotene/d (n = 54) orally for 4 y. In a multivariate analysis, baseline serum concentrations of the analytes, sex, body mass index, diet, smoking status, and age were associated with variable changes in some analytes over the 4-y period but supplementation with beta-carotene was related only to a mean increase in serum beta-carotene itself of 151%. We excluded with 95% confidence an increase in lycopene > 4.9%, an increase in alpha-carotene > 17.6%, and a decrease in lutein > 14.7% in subjects given beta-carotene. These results confirm previous findings that supplementation with beta-carotene given orally does not alter serum concentrations of retinol or alpha-tocopherol. The findings also indicate that beta-carotene supplementation, which results in a moderate increase in serum beta-carotene concentration, does not significantly change serum concentrations of other carotenoids.

Adult

Coffee and tea and the risk of recurrent colorectal adenomas.

Consumption of coffee has been associated with a reduction in the risk of cancer of the colon, and (less consistently) drinking tea has been associated with a reduction in the risk of rectal cancer. The effect of these beverages on the risk of colorectal adenomas, however, has not been well investigated. We used data from an adenoma prevention trial to investigate these associations. Patients with at least one recent large bowel adenoma were followed with colonoscopy 1 and 4 years after their qualifying examinations. Adenomas detected at the year 4 colonoscopy were used as end points. A food frequency questionnaire was administered at study entry and study completion; average intake over the study period was used to estimate the exposures of interest. There was no apparent association between the intake of regular coffee, decaffeinated coffee, or tea and the risk of recurrent colorectal adenomas. The relative risks and 95% confidence intervals per cup daily were 0.96 (0.87-1.05) for regular coffee, 0.97 (0.84-1.12) for decaffeinated coffee, and 1.02 (0.83-1.25) for tea. These negative findings were present both overall and for adenomas of the right and left large bowel.

Adenoma

Risk of squamous cell carcinoma of the skin in relation to plasma selenium, alpha-tocopherol, beta-carotene, and retinol: a nested case-control study.

We conducted a nested case-control study of squamous cell skin cancer (SCC) to determine whether risk was related to plasma concentrations of selenium, alpha-tocopherol, beta-carotene, and retinol. We derived the study sample from participants in our Skin Cancer Prevention Study, all of whom had at least one basal cell or squamous cell skin cancer before study entry. Those who developed a new squamous cell skin cancer during the 3-5-year follow-up period were selected as cases (n = 132). Controls (n = 264) were chosen at random, with matching by age, sex, and study center, from among those who did not develop SCC but were being followed actively at the time the SCC case was diagnosed. Prediagnostic plasma samples were analyzed for alpha-tocopherol, beta-carotene, and retinol using high-performance liquid chromatography. Selenium determinations were made using instrumental neutron activation analysis. Odds ratios were computed using conditional logistic regression for matched samples. We found no consistent pattern of SCC risk associated with any of the nutrients examined. The odds ratios (95% confidence intervals) for the highest versus the lowest quartiles of beta-carotene, retinol, alpha-tocopherol, and selenium were 0.73 (0.38-1.41), 1.43 (0.77-2.64), 0.89 (0.43-1.85), and 0.86 (0.47-1.58), respectively. Thus, our data add to the growing body of evidence that these nutrients, at the concentrations we evaluated, are not related strongly to SCC risk.

Adult

Intake of carrots, spinach, and supplements containing vitamin A in relation to risk of breast cancer.

Intake of fruits, vegetables, vitamin A, and related compounds are associated with a decreased risk of breast cancer in some studies, but additional data are needed. To estimate intake of beta-carotene and vitamin A, the authors included nine questions on food and supplement use in a population-based case-control study of breast cancer risk conducted in Maine, Massachusetts, New Hampshire, and Wisconsin in 1988-1991. Multivariate-adjusted models were fit to data for 3543 cases and 9406 controls. Eating carrots or spinach more than twice weekly, compared with no intake, was associated with an odds ratio of 0.56 (95% confidence interval 0.34-0.91). Estimated intake of preformed vitamin A from all evaluated foods and supplements showed no trend or monotonic decrease in risk across categories of intake. These data do not allow us to distinguish among several potential explanations for the protective association observed between intake of carrots and spinach and risk of breast cancer. The findings are, however, consistent with a diet rich in these foods having a modest protective effect.

Adult

Risk of basal cell and squamous cell skin cancers after ionizing radiation therapy. For The Skin Cancer Prevention Study Group.

BACKGROUND: Human evidence that ionizing radiation is carcinogenic first came from reports of nonmelanoma skin cancers (NMSCs) on the hands of workers using early radiation devices. An increased risk of NMSC has been observed among uranium miners, radiologists, and individuals treated with x rays in childhood for tinea capitis (ringworm of the scalp) or for thymic enlargement; NMSC is one of the cancers most strongly associated with the atomic bombing of Hiroshima and Nagasaki. Although exposure to ionizing radiation is a known cause of NMSC, it is not yet clear whether therapeutic radiation causes both major histologic types of NMSC, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Additionally, the potentially modifying effects, such as latency, age when treated, and type of treatment, are not well understood. PURPOSE: We investigated the relative risks of BCC and SCC associated with previous radiation therapy and evaluated these risks in relation to age and time since initial treatment and the medical condition for which radiation therapy was given. METHODS: The study group comprised individual diagnosed with at least one BCC or SCC from January 1980 through February 1986, who were recruited to participate in a skin cancer prevention trial designed to test whether oral beta-carotene supplementation would reduce the risk of new NMSCs. Patients were identified through the dermatology and pathology records of academic medical centers in Hanover, NH; Los Angeles, CA; San Francisco, CA; and Minneapolis, MN. Each participant completed a questionnaire detailing lifetime residence, pigmentary characteristics, occupational and recreational sun exposure, and history of radiation therapy. At enrollment, a study dermatologist assessed skin type (tendency to burn or tan) and extent of actinic skin damage. Participants were followed with an annual dermatologic examination for an average of 4 years. Of the 5232 potentially eligible individuals, 1805 were enrolled in the trial. We excluded 112 patients who reported previous radiation therapy for skin cancer only and three with missing information on whether they were ever treated with radiation therapy, leaving 1690 patients for the analysis. Approximately 4% of the patients died or discontinued participation for other reasons during each study year. We examined time to occurrence of first new histopathologically confirmed BCC and SCC during the follow-up period in relation to history of radiation therapy (for reasons other than NMSC) using a proportional hazards model. A multiple end points survival model was used to compare the rate ratios (RRs) for BCC and SCC. We also used a longitudinal method of analysis to compute the RR of total new BCC and SCC tumors per person per study year associated with radiation therapy. Using this method, we additionally assessed the potential modifying effects of age at treatment, latency, and type of therapy. All P values were derived from two-sided statistical tests of significance. RESULTS: Among the participants we studied, 597 developed a new BCC (n = 1553 tumors) and 118 developed a new SCC (n = 179 tumors). The time to first new BCC, but not SCC, was associated with prior radiation therapy (RR = 1.7; 95% confidence interval [CI] = 1.4-2.0 and RR = 1.0; 95% CI = 0.6-1.7, respectively; P = .03 for the difference between the RRs). The RR of total BCC tumors was slightly higher (RR = 2.3; 95% CI = 1.7-3.1), but it was still unity for SCC (RR = 1.0; 95% CI = 0.5-1.9). BCC risk appeared to increase with younger age at exposure and time since initially treated, although these effects were only marginally statistically significant (P for trend = .06 and .07, respectively). Also, risk of BCC was more strongly related to treatment for acne (RR = 3.3; 95% CI = 2.1-5.2) than other conditions. CONCLUSIONS AND IMPLICATIONS: Our data suggest that exposure to therapeutic radiation is associated with BCC but not with SCC.

Adult

Mortality associated with low plasma concentration of beta carotene and the effect of oral supplementation.

OBJECTIVE: To examine the relationship between beta carotene plasma concentration and beta carotene supplementation and risk of death from major disease causes. DESIGN: Cohort study of plasma concentrations; randomized, controlled clinical trial of supplementation. SETTING: Medical school-affiliated dermatology practices. PATIENTS: A total of 1188 men and 532 women with mean age of 63.2 years, who had enrolled in a randomized clinical trial of beta carotene supplementation to prevent nonmelanoma skin cancer. INTERVENTION: Oral beta carotene, 50 mg per day for a median of 4.3 years. MAIN OUTCOME MEASURES: All-cause mortality and mortality from cardiovascular disease and cancer. RESULTS: During a median follow-up period of 8.2 years, there were 285 deaths. Persons whose initial plasma beta carotene concentrations were in the highest quartile (>0.52 micromol/L [27.7 microg/dL]) had a lower risk of death from all causes (adjusted relative rate [RR], 0.52; 95% confidence interval [CI] 0.44 to 0.87) and from cardiovascular diseases (adjusted RR, 0.57; 95% CI, 0.34 to 0.95) compared with persons with initial concentrations in the lowest quartile (<0.21 micromol/L [11.2 microg/dL]). Patients randomly assigned to beta carotene supplementation showed no reduction in relative mortality rates from all causes (adjusted RR, 1.03; 95% CI, 0.82 to 1.30) or from cardiovascular disease (adjusted RR, 1.16; 95% CI, 0.82 to 1.64). There was no evidence of lower mortality following supplementation among patients with initial beta carotene concentrations below the median for the study group. CONCLUSIONS: These analyses provide no support for a strong effect of supplemental beta carotene in reducing mortality from cardiovascular disease or other causes. Although the possibility exists that beta carotene supplementation produces benefits that are too small or too delayed to have been detected in this study, noncausal explanations should be sought for the association between plasma concentrations of beta carotene and diminished risk of death.

Administration, Oral

Preventing colorectal cancer.

After decades of little apparent progress against colorectal cancer, we now have the means to avert many of the deaths associated with this malignancy. Earlier diagnosis, either through screening for fecal occult blood or by endoscopy, has been clearly shown to be effective in reducing mortality. There are also prospects for preventing colorectal cancer occurrence through life-style change, since epidemiological studies consistently show that a dietary pattern of high intake of fruits, vegetables, and fiber is associated with a substantially decreased risk of these tumors. A further approach to prevention is the use of pharmacologic agents. Several randomized prevention trials to assess possible preventive drugs or nutrient supplements have focused on patients treated for colorectal adenomas. These trials are feasible, but they pose important challenges in protocol design, recruitment, and patient compliance. Nonsteroidal anti-inflammatory drugs (NSAIDs), especially aspirin, currently appear to be the most promising agents for testing in future trials.

Adenoma

Regional differences in the incidence and treatment of carcinoma in situ of the breast.

Greater use of mammography in the United States in recent years has increased the detection of early neoplasms of the breast, including carcinoma in situ. However, the occurrence and treatment of diagnosed carcinoma in situ of the breast has not been fully described. Our goal was to examine temporal, geographic, and demographic patterns in the incidence and treatment of in situ breast cancer. The study included data from all women with in situ breast cancer that had been detected in the nine Surveillance, Epidemiology, and End Results areas of the United States from 1975 through 1990 (Surveillance Program, Cancer Statistics Branch, Bethesda, MD: National Cancer Institute, November, 1993). We calculated age-adjusted incidence rates (1970 United States standard) using data on histology and treatment from the Surveillance, Epidemiology, and End Results data tape. We assessed predictors of treatment by mastectomy using multiple logistic regression. From 1975-1979 to 1986-1990, the age-adjusted incidence rate of in situ breast cancer increased from 4.7 to 16.9/100,000 women. The increase occurred in all age groups and among both white and black women. However, there was nearly a 2-fold difference in incidence rates across geographic areas in 1986-1990, ranging from < 12/100,000 in Iowa and New Mexico to > 20/100,000 in San Francisco and Seattle. Geographic variability in treatment was also evident, with mastectomy, rather than breast-conserving therapy, performed on 46% of the women with in situ breast cancer in San Francisco and on 66% of those in Iowa. The incidence of diagnosed in situ breast cancer increased markedly during the 1980s, and there was substantial geographic variability in the rates of detection of these tumors and in the type of therapy received. Although mastectomy became a less common treatment over time, it was still performed on a high proportion of women with in situ breast cancer during the latter part of the decade.

Adult

Reliability of whole crypt mitotic count as a measure of cellular proliferation in rectal biopsies.

We conducted a reliability study of whole crypt mitotic count, a measure of cellular proliferation with potential use as an intermediate marker in studies of colorectal cancer risk and prevention. The study involved biopsies taken from two distinct locations at 8-10 cm from the anal verge for 20 subjects scheduled to undergo routine endoscopy. In addition to the overall count of mitoses per crypt (mitotic count), we investigated two novel measures based on the percentages of heights of mitotic cells within crypts: the mean height, and the maximum minus minimum (max - min) height of mitoses. The max - min height was positively correlated with mitotic count (r = 0.64); however, there was little correlation between mitotic count and the mean height of mitotic cells (r = 0.12). Components of variance were estimated for the three measures; for mitotic count and max - min height, the variability between persons was substantially greater than that between locations within an individual. For mean height, the between-person and between-location variabilities were roughly equal. These results suggest that whole crypt mitotic count has promise as a reliable measure of rectal cellular proliferation, but further studies will be necessary to assess the utility of this assay.

Adult

Toenail samples as an indicator of drinking water arsenic exposure.

We conducted a pilot study to assess the utility of toenail arsenic concentrations as an indicator of ingestion of arsenic-containing water. We enrolled 21 individuals whose household drinking water supply was provided by a private well, including 10 individuals who lived in areas of New Hampshire where elevated water levels of arsenic had been reported previously. Participants were interviewed regarding use of their private (unregulated) wells for drinking and cooking, and each provided a sample of water and toenail clippings. All specimens were analyzed using instrumental neutron activation analysis with a sensitivity of approximately 0.001 parts per million (ppm). Trace concentrations of arsenic were detected in 15 of the 21 well water samples and in all toenail clipping samples. Among the 10 individuals who lived in areas with reportedly high arsenic levels in the water supply, the geometric mean toenail concentration was 0.39 ppm (SE, 0.12 ppm); among the other 11 persons, the geometric mean was 0.14 ppm (SE, 0.02 ppm; P = 0.005 for the difference between the two means). The overall Spearman correlation between toenail and well water arsenic was 0.67 (P = 0.009), and among those with detectable well water levels of arsenic, the Spearman correlation was 0.83 (P = 0.0001). Based on the regression analysis of those who had detectable water levels of arsenic, a 10-fold increase in well water concentrations of arsenic was reflected by about a 2-fold increase in toenail concentrations. These results indicate that concentrations of arsenic in toenails reflect use of arsenic-containing drinking water.

Adult

Aspirin and other nonsteroid anti-inflammatory drugs as cancer-preventive agents.

Several lines of evidence support the notion that aspirin and other nonsteroid anti-inflammatory drugs (NSAIDs) may prevent human cancer, particularly cancers of the large bowel. These drugs are potent inhibitors of cyclo-oxygenases, enzymes that catalyse the synthesis of prostaglandins from arachidonic acid. In rodent models, NSAIDs consistently inhibit chemically induced neoplasms of the colorectum. Case reports and randomized controlled trials are also consistent in showing a reduction in adenomas following administration of the NSAID sulindac to patients with familial adenomatous polyposis. Perhaps the most intriguing evidence, however, comes from epidemiological studies, which indicate a 30-50% reduction in risk of colorectal neoplasia among regular users of aspirin. These studies have employed both case-control and cohort approaches, and lower risk has been found for colon and rectal cancer mortality, invasive cancer incidence, and adenoma occurrence. The results of the epidemiological studies are not uniform, however, and a few studies found no benefit with aspirin use. Existing epidemiological studies are limited by a lack of information about dosage and duration of aspirin use. Moreover, questions remain about the mechanism through which NSAIDs might affect cancer occurrence. Thus, there is a clear need for focused clinical trials, as well as for further epidemiological study and laboratory investigation, to define better the potential of these agents to prevent cancers.

Anti-Inflammatory Agents, Non-Steroidal

Risk of breast cancer in relation to lifetime alcohol consumption.

BACKGROUND: Although an association between alcohol consumption and risk of breast cancer has been observed in many studies, questions of major importance remain, including the nature of the dose-response relationship and the effects of drinking at various periods in life. PURPOSE: Our goal was to address the issues listed above with a large case-control study. METHODS: We conducted a population-based case-control study in Maine, Massachusetts (excluding the four counties that include metropolitan Boston), New Hampshire, and Wisconsin. Case patients were eligible if their diagnosis of invasive breast cancer was first reported to one of the four statewide cancer registries during the period of 1988 through 1991. During the accrual period, 11,879 potentially eligible case patients and 16,217 control subjects were identified. After excluding ineligible women from the study, telephone interviews were obtained from 6888 case patients and 9424 control subjects. Complete data for recent alcohol consumption, and thus final eligibility for study participation, were determined for 6662 case patients and 9163 control subjects. The average age at time of interview was 58.7 years. The questions on alcohol use addressed average consumption during five periods of the subjects' lives: ages 16-19, 20-29, 30-39, 40-59, and 60-74 years. Similar responses from 211 control subjects upon reinterview 6-12 months later were taken to be indicative of the reliability of the questionnaire used in this study. RESULTS: Lifetime average alcohol consumption (measured as the average grams per day consumed from age 16 to the recent past) and recent alcohol consumption (average grams per day consumed in the previous age interval) were associated with risk of developing breast cancer. The multivariate relative risk of breast cancer, in those who drink compared with abstainers, associated with average lifetime consumption of 12-18 g/day of alcohol (about one drink) was 1.39 (95% confidence interval [CI] = 1.16-1.67), of 19-32 g/day (about two drinks) was 1.69 (95% CI = 1.36-2.10), of 33-45 g/day (about three drinks) was 2.30 (95% CI = 1.51-3.51), and of greater than or equal to 46 g/day (four or more drinks) was 1.75 (95% CI = 1.16-2.64) (P for trend < .0001). The multivariate relative risk per 13 g/day (about one drink) of alcohol consumed before 30 years of age was 1.09 (95% CI = 0.95-1.24), whereas the relative risk associated with recent consumption of 13 g/day was 1.21 (95% CI = 1.09-1.34). CONCLUSIONS: In these data, alcohol consumption was clearly related to breast cancer risk. Risk appeared to increase even at moderate levels of consumption. For women of all ages combined, consumption before 30 years of age was not an important determinant of risk.

Adolescent

Long-term morbidity following jejunoileal bypass. The continuing potential need for surgical reversal.

OBJECTIVE: To review the late sequelae of jejunoileal bypass (JIB) and the potential role of late surgical reversal in ameliorating morbidity and mortality following JIB. DESIGN: Patients who underwent JIB between 1965 and 1977 were contacted and pertinent health-event information was gathered. Early sequelae were defined as disorders occurring within the first 2 years after JIB; late sequelae were those occurring after 2 years. Health events occurring between 0 and 23 years after JIB were documented. SETTING: A private, tertiary referral center. PATIENTS: Patients underwent JIB for morbid obesity that had failed medical and/or psychiatric interventions. MAIN OUTCOME MEASURES: Body mass index (BMI) (weight kilograms divided by the square of the height in meters), diarrhea, electrolyte imbalance, acute, and chronic liver disease, renal disease, JIB reversal, reason for JIB reversal, death, and cause of death. RESULTS: A total of 453 morbidity obese patients underwent JIB. By 2 years following JIB, the mean (+/- SD) BMI dropped from 49.3 +/- 8.1 to 31.1 +/- 0.8 and remained at this level until year 15, after which weight gradually increased (BMI, 35.4 +/- 3.1). The most severe early complication was acute liver failure, which occurred in 7% of patients and caused seven deaths. At 15 years, the actuarial probability of the most common serious late complications related to JIB were renal disease (37%), with two deaths; diarrhea (29%); and liver disease (10%), with three deaths. One hundred thirty-eight patients (31%) had a bypass reversal. The most common indications for reversal were diarrhea and electrolyte disturbance (29%), renal disease (19%), and liver disease (17%). Fifty-six patients died more than 30 days after JIB: 64% before JIB reversal, 13% at the time of reversal, and 23% subsequently. CONCLUSIONS: Jejunoileal bypass is associated with progressive accrual of serious, sometimes life-threatening complications. Lifelong follow-up for early diagnosis and surgical reversal before life is threatened should reduce the morbidity and mortality associated with this procedure.

Acid-Base Imbalance

Strenuous physical activity in young adulthood and risk of breast cancer (United States).

The epidemiologic data on the relation between strenuous physical activity and breast cancer are limited and inconsistent. Because risk of breast cancer may be influenced by ovarian function which, in turn is modulated by physical activity, the hypothesis that exercise may be associated with a reduced risk of breast cancer merits further investigation. We, therefore, conducted a large case-control study in 1988-1991, and interviewed 6,888 women (17 to 74 years of age) with breast cancer in Maine, Massachusetts, New Hampshire, and Wisconsin (United States). Interviewed controls (9,539 women, 18 to 74 years of age) were selected randomly from lists of licensed drivers (for younger women) or from a roster of Medicare enrollees (for older women). We used multivariate adjusted odds ratios (OR) and 95 percent confidence intervals (CI) from logistic regression models to estimate relative risks between self-reported physical activity when 14 to 22 years of age and breast cancer. When compared with sedentary controls, women who reported any strenuous physical during ages 14 to 22 years had a modest reduction in the risk of breast cancer (OR = 0.95, CI = 0.93-0.97). However, those who exercised vigorously at least once a day had a 50 percent reduction in risk of breast cancer (OR = 0.5, CI = 0.4-0.7). These data support the hypothesis that women who are physically active have a reduced risk of breast cancer.

Adolescent

Nonsteroidal antiinflammatory drugs and human cancer. Report of an interdisciplinary research workshop.

BACKGROUND: Since the 1970s, work in several disciplines (toxicology, pharmacology, clinical medicine, epidemiology) increasingly has suggested that aspirin and other nonsteroidal antiinflammatory drugs (NSAIDs) may reduce the occurrence or progression of colorectal cancers and polyps and perhaps of other gastrointestinal tumors. The potential application of these findings for chemoprevention of such cancers in man now deserves serious consideration. METHODS: An interdisciplinary workshop was held by the American Cancer Society in March 1994 to review the current knowledge of NSAIDs and cancer and to seek a consensus on future research directions, particularly concerning the possibility of randomized prevention trials in human populations. RESULTS: A wide-ranging review was conducted of past and current research regarding (1) NSAIDs' effects in experimental animal cancer models; (2) clinic experience in NSAID treatment, particularly in familial polyposis; (3) pharmacologic studies regarding the enzymatic and metabolic actions of NSAIDs; and (4) epidemiologic observations on the relationship of aspirin/NSAID usage to colorectal cancer occurrence in human populations. CONCLUSIONS: Combined evidence from different research disciplines strongly supports the notion that aspirin and other NSAIDs act to prevent the development or progression of certain human gastrointestinal cancers, especially colorectal cancer. Consequently, the workshop recommended that randomized prevention trials be undertaken. For various logistic reasons, such trials probably should focus on NSAID effects on the occurrence and progression of colorectal polyps rather than on carcinoma itself. Continued research also is needed to clarify further the pharmacologic, clinical, and epidemiologic nature of NSAIDs' influences on human carcinogenesis.

Animals