Pubertal anthropometry in sons and daughters of women with preeclamptic or normotensive pregnancies.

OBJECTIVE: To compare body mass index (BMI) and waist and hip circumference in early puberty (10.8 years in girls and 11.8 years in boys) among offspring of preeclamptic and normotensive pregnancies. DESIGN: Population based follow-up study. METHODS: Anthropometry measured in early puberty in 91 girls and 92 boys of preeclamptic pregnancies, and in 194 girls and 166 boys of normotensive pregnancies, with similar anthropometric measures among mothers, performed at the beginning of the index pregnancy, and at follow-up, when their offspring were in early puberty. RESULTS: Among girls, the preeclampsia group had higher body mass (BMI 18.3 kg/m(2) vs 17.5 kg/m(2), p = 0.01) and larger waist circumference (63.7 cm vs 61.6 cm, p = 0.05) compared to the normotensive group, but the differences were restricted to the offspring of mothers with a high body mass (BMI >30 kg/m(2)). Among boys, we observed no differences in anthropometric measurements between groups. CONCLUSIONS: The higher BMI and larger waist of daughters of women with preeclampsia was only present if their mothers were obese. These results suggest that preeclampsia in obese women may lead to a distinct disadvantage in body size for their daughters in early puberty.

Maternal-recalled gestational weight gain, pre-pregnancy body mass index, and obesity in the daughter.

OBJECTIVE: Emerging evidence suggests that exposures during fetal life affect adult metabolism. We assessed the relationship between recalled maternal pre-pregnancy body mass, gestational weight gain (GWG), and adiposity in the daughter. DESIGN: Retrospective cohort study among mother-nurse daughter dyads in the Nurses' Health Study II and the Nurses' Mothers' Cohort. Mothers of participants completed questionnaires regarding their nurse daughter in 2001. PARTICIPANTS: 26,506 mother-nurse daughter dyads born between 1946 and 1964. MAIN OUTCOME MEASURES: Body mass index (BMI) of the nurse daughter at age 18 and in 2001. RESULTS: At age 18, 561 (2.1%) daughters were obese (BMI>30), and in 2001, 5442 (22.0%) were obese. Adjusting for covariates, women whose mothers had a recalled pre-pregnancy BMI of 29 had a 6.1-fold increased risk of obesity at age 18 and a 3.4-fold risk of obesity in 2001, compared with women whose mothers had a pre-pregnancy BMI of 21. We found a U-shaped association between recalled GWG and offspring obesity. Compared with a maternal weight gain of 15-19 lb, GWG <10 lb was associated with a significant increase in obesity risk at age 18 (odds ratio (OR) 1.54, 95% confidence interval (CI) 1.02-2.34) and in 2001 (OR 1.27, 95% CI 1.05-1.53). High weight gain (40+lb) was also associated with obesity risk at age 18 (OR 1.81, 95% CI 1.22-2.69) and in 2001 (OR 1.74, 95% CI 1.48-2.04). These associations were stronger among mothers who were overweight before pregnancy (P for interaction=0.03), and they persisted with adjustment for birth weight. CONCLUSION: A high recalled pre-pregnancy BMI and extremes of recalled GWG are associated with an increased risk of adolescent and adult obesity in offspring, particularly when the mother is overweight. Pre-pregnancy weight and GWG may be modifiable fetal origins of overweight and obesity in women.

Components of variation in serum carotenoid concentrations: the Polyp Prevention Trial.

OBJECTIVES: The intra- and interindividual variations and season and center effects were estimated from a series of serum carotenoid concentrations in the Polyp Prevention Trial (PPT) participants. SUBJECTS/METHODS: Fasting blood was collected annually for 4 years in all 1905 participants, and a subcohort of 901 participants were selected within each (of eight) center(s), by gender and dietary arm of the study, for measurement of five major carotenoid peaks. Using variance of component methods, the variation in serum carotenoid concentrations about the underlying mean was partitioned into explanatory components attributed to various sources. RESULTS: The contributions of the inter- and intraindividual variances to the overall variation in carotenoid concentrations were in the range of 61-70 and 20-35%, respectively, whereas center and center-by-season effects provided 2.6-9.5 and 0.2-1.4%, respectively. The highest percent (35%) of intraindividual variation was exhibited by lycopene, and the highest percent (70% apiece) of interindividual variation was exhibited by lutein/zeaxanthin and beta-carotene. Serum lycopene had the highest ratio of intra- to interindividual variation of 0.57, whereas lutein had the lowest ratio of 0.29. We estimate that the ratio of intra- to interindividual variance around the mean carotenoid concentration can be reduced greatly by collecting 3-4 compared to 1 blood measurement in large-scale trials like the PPT. CONCLUSION: In the largest study of components of variation in individuals at high risk for colorectal cancer, the largest contributors to variation in serum carotenoid concentrations were intra- and interindividual effects followed by center and center-by-season effects.

Association of early life factors and brain tumour risk in a cohort study.

Using population-based linked birth and cancer registry data, we investigated whether the risk of brain tumour in childhood (n=155) was associated with perinatal risk factors. This population-based cohort showed that being born into a larger family or to a mother with a history of miscarriage may increase childhood brain tumour risk.

Dietary boron and hormone replacement therapy as risk factors for lung cancer in women.

Hormone replacement therapy (HRT) may reduce lung cancer risk. Dietary boron may have actions similar to those of HRT; however, no previous study has reported the associations between dietary boron intake and lung cancer risk or the joint effects of boron intake and HRT use on lung cancer risk. The authors examined the associations between boron intake and the joint effects of boron intake and HRT on lung cancer risk in women. In an ongoing case-control study in Houston, Texas (July 1995 through April 2005, end date for this analysis), 763 women were diagnosed with lung cancer, and 838 were matched healthy controls with data on both diet and HRT. Multiple logistic regression analyses were conducted to assess the associations between dietary boron and HRT with lung cancer risk. After adjustment for potential confounders, the odds ratios for lung cancer with decreasing quartiles of dietary boron intake were 1.0, 1.39 (95% confidence interval (CI): 1.02, 1.90), 1.64 (95% CI: 1.20, 2.24), and 1.95 (95% CI: 1.42, 2.68) mg/day, respectively, for all women (p(trend) < 0.0001). In joint-effects analyses, compared with women with high dietary boron intake who used HRT, the odds ratio for lung cancer for low dietary boron intake and no HRT use was 2.07 (95% CI: 1.53, 2.81). Boron intake was inversely associated with lung cancer in women, whereas women who consumed low boron and did not use HRT were at substantial increased odds.

A longitudinal study of infant feeding and obesity throughout life course.

BACKGROUND: The Centers for Disease Control and Prevention and the US Department of Health and Human Services promote breastfeeding as a strategy for reducing childhood overweight. We evaluated the relation between infant feeding and the development of overweight and obesity throughout life course. METHODS: We investigated the association between infant feeding and obesity among 35,526 participants in the Nurses' Health Study II who were followed prospectively from 1989 to 2001. Mothers of participants provided information by mailed questionnaires on the duration of breast- and bottle-feeding, as well as the type of milk or milk substitute in the bottle. Information on body shape at ages 5 and 10, weight at age 18, current weight between 1989 and 2001, and height was reported by the participants. RESULTS: The duration of breastfeeding, including exclusive breastfeeding, was not related to being overweight (25< or = body mass index (BMI) <30 kg/m(2)) or obese (BMI> or =30 kg/m(2)) during adult life. Women who were exclusively breastfed for more than 6 months had a risk of 0.94 (95% confidence interval (CI) 0.83-1.07) of becoming obese as adults compared with women who were not breastfed. Exclusive breastfeeding for more than 6 months was associated with leaner body shape at age 5 (odds ratio (OR)=0.81; 95% CI 0.65-1.01 for the highest vs the lowest category of body shape) compared to women who were not breastfed or breastfed for less than 1 week, but this association did not persist during adolescence or adulthood. CONCLUSIONS: We did not find that having been breastfed was associated with women's likelihood of becoming overweight or obese throughout life course. Although breastfeeding promotes the health of mother and child, it is unlikely to play an important role in controlling the obesity epidemic.

The negative association between pre-eclampsia and breast cancer risk may depend on the offspring's gender.

If the negative association between pre-eclampsia and subsequent breast cancer risk differs by gender, this would strengthen the hypothesis that factors intrinsic to the particular pregnancy may explain the association. The study included 701,006 parous Norwegian women with follow-up for breast cancer through the Cancer Registry of Norway. Breast cancer risk was lower in women with pre-eclampsia/hypertension in their first pregnancy, compared to other women (relative risk, 0.86, 95% CI, 0.78-0.94), after adjustment for age at first birth, maternal birth year, length of gestation, marital status, and parity. The risk reduction was slightly greater if the woman delivered a son as opposed to a daughter (relative risks of 0.79 vs 0.94, P-value for interaction, 0.06), and if pre-eclampsia/hypertension was combined with pre-term delivery, these differences were more pronounced (relative risks, 0.62 vs 1.07, P-value for interaction 0.03). A subanalysis among 176,036 primiparous women showed a substantial risk reduction if the mother delivered a son (relative risk, 0.62, 95% CI, 0.47-0.82), but essentially null if she delivered a daughter (relative risk, 0.92, 95% CI, 0.72-1.18; P-value for interaction, 0.05). These results suggest that the effect of pre-eclampsia/hypertension may be attributed to factors associated with the particular pregnancy rather than an underlying biological trait of the mother. The stronger risk reduction related to having a son suggests a role for sex-dependent hormones in pregnancy.

Nutrition and cancer prevention: a multidisciplinary perspective on human trials.

More than one million Americans were expected to be diagnosed with cancer in 2003 (7a). Compelling experimental, epidemiological, and clinical evidence indicates that many cancers are preventable, especially because diet and nutrition are key factors in the modulation of cancer risk. The road to nutritional intervention in cancer prevention has led to successful trials as well as trials that did not reach their intended endpoints. This chapter reviews four case studies of trials, with two ending in success and two ending in null findings or adverse effects. The goal is to identify lessons learned from all four case studies and from the investigations of the complexities inherent to nutritional intervention trials. Additional insights are presented by the research addressing potential mechanisms underlying the endpoints of human trials. Future progress in nutrition and cancer prevention will require expertise from multidisciplinary teams to develop new knowledge about specific nutrients and dietary modifications within a framework of interaction between animal and human research.

Serum carotenoids are associated with increased lung cancer risk among alcohol drinkers, but not among non-drinkers in a cohort of tin miners.

To examine the association between pre-diagnostic serum carotenoid levels and lung cancer risk and the effects of alcohol intake on the carotenoid-lung cancer relationship, we conducted a case-control study in an occupational cohort from the Yunnan Tin Corporation in China. During 6 years of follow-up, 339 cases of confirmed lung cancer were diagnosed. Among these cases, those who donated pre-diagnostic blood (n = 108) were eligible for this study. For each case, two individuals alive and free of cancer at the time of case diagnosis, matched on age, sex, and date of blood collection, were selected as controls. Serum beta-carotene (odds ratios (ORs) for tertiles: 1, 1.3, 2.0) and beta-cryptoxanthin (ORs for tertiles: 1, 1.8, 2.9) levels were positively associated with lung cancer risk after adjustment for tobacco use and radon exposure. Among alcohol drinkers, higher serum carotenoid levels were significantly associated with increased lung cancer risk (alpha-carotene OR 2.2, 95% confidence interval (CI) 1.1-4.4, beta-carotene OR 7.6, 95% CI 3.1-18.6, lutein/zeaxanthin OR 2.3, 95% CI 1.2-6.6 and beta-cryptoxanthin OR 7.6, 95% CI 2.7-21.5). Conversely, risk estimates among non-drinkers suggest a possible protective association for higher carotenoid levels.

Serum tocopherols, selenium and lung cancer risk among tin miners in China.

OBJECTIVE: To evaluate the association of prediagnostic serum antioxidants and lung cancer risk we conducted a case-control study nested in an occupational cohort of tin miners. METHODS: Male workers free of cancer enrolled in the cohort. During up to 6 years of follow-up, 339 lung cancer cases were diagnosed and, among these cases, those who donated blood prospectively (n = 108) were eligible for this study. For each case, two controls alive and free of cancer at the time of case diagnosis were matched on age and date of blood collection. RESULTS: Overall, we observed no association between serum alpha-tocopherol, gamma-tocopherol or selenium levels and lung cancer risk. However, a significant gradient of decreasing lung cancer risk with increasing serum alpha-tocopherol was apparent for men less than 60 years old (odds ratio by tertile: 1.0, 0.9, 0.2; trend p = 0.002). Alpha-tocopherol was also protective in men who reported no alcohol drinking (OR by tertile: 1.0, 0.6, 0.3; trend p = 0.008). CONCLUSION: Although there were no significant overall associations between prospectively collected serum alpha-tocopherol, gamma-tocopherol or selenium and incidence of lung cancer, results from this study suggest that higher alpha-tocopherol levels may be protective in men less than 60 years old and in those who do not drink alcohol.

Relative validity of a food frequency questionnaire among tin miners in China: 1992/93 and 1995/96 diet validation studies.

OBJECTIVE: Diet validation research was conducted to compare the respondents' reporting of dietary intake in a food frequency questionnaire (FFQ) with intake reported in food recalls. Because the population received annual salary increments that could modify food intake, diet validation studies (DVSs) were conducted during two time intervals. DESIGN: A 99-item FFQ was administered by an interviewer twice in a 1-year interval, and responses to each FFQ item were compared with 28 days of interviewer-administered food recalls that were collected in four 1-week intervals during each season of 1992/93. The second validation study in 1995/96 had a similar design to the earlier one. SETTING: A prospective cohort study of lung cancer among tin miners in China was initiated in 1992, with dietary and other risk factors updated annually. SUBJECTS: Among a cohort of high risk tin miners for lung cancer, two different samples (n = 141 in 1992/93, and n = 113 in 1995/96) for each diet validation study were randomly selected from four mine units, that were representative of all worker units. RESULTS: Miners reported a significantly higher average frequency of intake of foods in the food recalls than the FFQ, with few exceptions. Deattenuated Pearson correlation coefficients of the frequency of food intake between the FFQ and food recalls were in the range of -0.40 to 0.72 in both studies, with higher positive correlations for beverages and cereal staples than for animal protein sources, vegetables, fruits and legumes. The percentage of individuals with exact agreement in the extreme quartiles of intake in the food recalls and FFQ ranged from 0 to 100% in both studies. CONCLUSIONS: Among Chinese miners, the range in correlations between the food recalls and the FFQ were due to: (i) market availability of foods during the food recall weeks compared to their annual reported intake in the FFQ; (ii) cultural perception of time; and (iii) differences in how the intake of mixed dishes and their multi-ingredient foods were reported in the recalls vs. the FFQ. The range in the percentage of agreement in the same quartiles and the changes in food intake over time may have implications for the analysis of the diet-disease relationship in this cohort.

Dietary carotenoids and vitamins A, C, and E and risk of breast cancer.

BACKGROUND: Data on intake of specific carotenoids and breast cancer risk are limited. Furthermore, studies of vitamins A, C, and E in relation to breast cancer risk are inconclusive. We have conducted a large, prospective study to evaluate long-term intakes of these nutrients and breast cancer risk. METHODS: We examined, by use of multivariate analysis, associations between intakes of specific carotenoids, vitamins A, C, and E , consumption of fruits and vegetables, and breast cancer risk in a cohort of 83234 women (aged 33-60 years in 1980) who were participating in the Nurses' Health Study. Through 1994, we identified 2697 incident cases of invasive breast cancer (784 premenopausal and 1913 postmenopausal). RESULTS: Intakes of beta-carotene from food and supplements, lutein/zeaxanthin, and vitamin A from foods were weakly inversely associated with breast cancer risk in premenopausal women. Strong inverse associations were found for increasing quintiles of alpha-carotene, beta-carotene, lutein/zeaxanthin, total vitamin C from foods, and total vitamin A among premenopausal women with a positive family history of breast cancer. An inverse association was also found for increasing quintiles of beta-carotene among premenopausal women who consumed 15 g or more of alcohol per day. Premenopausal women who consumed five or more servings per day of fruits and vegetables had modestly lower risk of breast cancer than those who had less than two servings per day (relative risk [RR] = 0.77; 95% confidence interval [CI] = 0.58-1.02); this association was stronger among premenopausal women who had a positive family history of breast cancer (RR = 0.29; 95% CI = 0.13-0.62) or those who consumed 15 g or more of alcohol per day (RR = 0.53; 95% CI = 0.27-1.04). CONCLUSIONS: Consumption of fruits and vegetables high in specific carotenoids and vitamins may reduce premenopausal breast cancer risk.

Evaluation of atypical and low-grade cervical cytology in private practice.

OBJECTIVE: To evaluate the adequacy of cytology alone for diagnosis of grade of cervical intraepithelial neoplasia (CIN) and to study performance of cytology, human papillomavirus (HPV) testing, and colposcopy in the evaluation of cytologic findings suggesting low-grade squamous intraepithelial lesions (SIL), or atypical squamous (ASCUS) or atypical glandular (AGCUS) cells of undetermined significance. METHODS: Standard gynecologic and cytologic evaluation and colposcopic inspection as an additional screening approach were performed on women with no prior hysterectomies screened in a private practice between January 1, 1993, and August 1, 1995. Among these 7651 women, 367 had ASCUS, AGCUS, or SIL cytology or clinically or colposcopically visible cervical lesions. Sensitivity, specificity, and relative risk of CIN in the 367 women were compared by colposcopic, cytologic, histologic and virologic diagnoses. RESULTS: The sensitivity of all non-negative Papanicolaou smears for CIN 2-3 and cancer was 92%, combined cytologic categories of high- and low-grade SIL were 59%, and high-grade SIL alone was 22%. Colposcopy was performed in all 367 patients, and positive findings led to biopsies in 48%. Colposcopy of patients with ASCUS increased detection of CIN 2-3 by 32% and CIN 1 by 48%. Cervical cytology was false negative in 8% of patients with CIN 2-3 and in 14% of those with CIN 1. These cases of CIN were detected by screening colposcopic inspection. High-risk HPV DNA was positive in 41% of women with CIN 2-3, and in 25% of those with CIN 1. The positive predictive value of ASCUS cytology increased from 5% to 42% for CIN 2-3 and from 30% to 85% for all grades of CIN in patients carrying high-risk HPV DNA. Virologic studies did not add to an increase in the sensitivity for CIN 2-3 among women in the low- and high-grade SIL cytology groups. CONCLUSION: Because of the limited sensitivity of the high-grade SIL cytologic category for CIN 2-3, we recommend that all women with ASCUS, AGCUS, low- or high-grade SIL cytology be recalled for colposcopy, with biopsy only when indicated by colposcopic findings.

alpha-Tocopherol concentrations in plasma but not in lipoproteins fluctuate during the menstrual cycle in healthy premenopausal women.

Because premenopausal women experience cyclic fluctuations of plasma carotenoids and their lipoprotein carriers, it was hypothesized that plasma alpha-tocopherol (A-T) fluctuates by phase of the menstrual cycle. Twelve free-living women, with a confirmed ovulatory cycle, were given a controlled diet for two consecutive menstrual cycles. Blood was drawn during the menses, early follicular, late follicular and luteal phases to simultaneously measure serum hormones, plasma lipoproteins and A-T concentrations, and A-T distribution in the lipoprotein fractions. Plasma A-T concentrations were significantly lower during menses than during the luteal phase by approximately 12% in each controlled diet cycle (P < 0.001). Adjustment for serum cholesterol and triglyceride concentrations did not alter these findings. The distributions of A-T in lipoprotein cholesterol fractions were not significantly different by menstrual phase. From 61 to 62% of A-T was concentrated in the LDL fraction, with another 9-14% in HDL2, 17-22% in HDL3 and the remaining 6-8% in VLDL+ IDL. There were no significant differences in lipoprotein cholesterol fractions by menstrual phase, except for a significant increase (P = 0.03) in HDL2 cholesterol from the early follicular to the late follicular phase. Spearman rank correlations from data during the second controlled diet month showed A-T in HDL2 in the late follicular phase was positively correlated with HDL cholesterol in the early follicular (r = 0.88), late follicular (r = 0.86) and luteal phases (r = 0.86) and with luteal apolipoprotein (ApoA-1) level (r = 0.90), and luteal HDL2 cholesterol (r = 0.83). A-T in HDL3 in the early follicular phase was negatively correlated with HDL2 cholesterol (r = -0.96) and ApoA-1 (r = -0.85), whereas luteal A-T in HDL3 was correlated with luteal HDL3 cholesterol (r = -0.79). Late follicular A-T in VLDL was positively correlated with early follicular HDL3 cholesterol and late follicular HDL3 cholesterol (r = 0.83). Fluctuations of A-T concentrations by phase of the menstrual cycle should be taken into consideration in future research concerning premenopausal women and the risk of chronic disease.

Associations of plasma carotenoid concentrations and dietary intake of specific carotenoids in samples of two prospective cohort studies using a new carotenoid database.

Diet-plasma carotenoid associations were examined in samples of women and men from each cohort in the Nurses' Health Study and the Health Professionals Follow-Up Study. In each sample, participants completed two self-administered food frequency questionnaires with at least a 1-year interval and provided a blood specimen preceding the second food frequency questionnaire. Carotenoid intakes were estimated from values for the five major carotenoids found in human plasma, specifically, alpha- and beta-carotene, beta-cryptoxanthin, lutein, and lycopene, using the United States Department of Agriculture-National Cancer Institute Carotenoid Database, as well as updated values for tomato products. Pearson correlation coefficients were calculated to compare diet-plasma correlations over time by sex after adjustment for recognized covariates. Among nonsmoking women (n = 162), the adjusted diet-plasma carotenoid associations were 0.48 for alpha-carotene, 0.27 for beta-carotene and lutein, 0.32 for beta-cryptoxanthin, and 0.21 for lycopene. Among nonsmoking men (n = 110), diet-plasma correlations were 0.47 for alpha-carotene and lycopene, 0.35 for beta-carotene, 0.43 for beta-cryptoxanthin, and 0.40 for lutein. Correlations between total fruit or vegetable intake and each plasma carotenoid level were not as high as any of the calculated carotenoid intake using the new database values. The correlations observed in this study indicate that the new carotenoid database provides valuable information on specific carotenoid intake and may be useful in epidemiological studies that attempt to account for associations between fruit or vegetable intake and disease.

Effect of menstrual cycle phase on the concentration of individual carotenoids in lipoproteins of premenopausal women: a controlled dietary study.

Because premenopausal women experience cyclic fluctuations of plasma carotenoids and their lipoprotein carriers, it is hypothesized that carotenoid concentrations in lipoprotein fractions fluctuate by phase of the menstrual cycle. Nine women ate a standard set of carotenoid-rich foods daily for two cycles under isoenergetic conditions. In the second cycle, hormones and carotenoids in lipoprotein fractions were measured in the early and late follicular and luteal phases. alpha-Carotene concentrations in the LDL fraction were lower in the early than in the late follicular phase (P = 0.03) on the basis of regression analysis. beta-carotene concentrations in the LDL fraction and the HDL2 subfraction were higher in the late follicular than in the luteal phase (P = 0.02 and P = 0.04, respectively). Lutein/zeaxanthin concentrations in the LDL and HDL fractions were higher in the late follicular than in the luteal phase (P = 0.03 and P = 0.02, respectively). In each phase, 80% of alpha-carotene, 82% of beta-carotene, 85% of lycopene, and 64% of lutein/zeaxanthin were distributed in the LDL fraction. Among the hydrocarbon cartenoids, 18% of alpha-carotene and of beta-carotene and 13% of lycopene were distributed in the HDL fraction, with slightly more in the HDL2 than in the HDL3 subfraction. In contrast 34% of lutein/zeaxanthin was distributed in the HDL fraction with more concentrated in the HDL3 than in the HDL2 subfraction. Less than 4% of any carotenoid was found in the VLDL + IDL (intermediate-density-lipoprotein) fractions. Thus, the hydrocarbon carotenoids were highly concentrated in the LDL fraction and xanthophyll was more evenly distributed in the LDL and HDL fractions. The cyclic fluctuations of these carotenoids in lipoprotein fractions add another dimension to the understanding of their transport and physiologic function.

Risk factors and early detection of lung cancer in a cohort of Chinese tin miners.

PURPOSE: To examine risk factors and establish a biologic specimen and data bank for the study of early markers of lung cancer. METHODS: We designed a dynamic cohort using an ongoing lung cancer screening program among radon- and arsenic-exposed tin miners in Yunnan China. Through the first four years of the study, 8,346 miners aged 40 years and older with over 10 years of occupational exposure have been enrolled, risk factors have been assessed, annual sputum and chest radiographs have been obtained, and numerous biologic specimens have been collected. RESULTS: A total of 243 new lung cancer cases have been identified through 1995. Radon and arsenic exposures are the predominant risk factors, but lung cancer risk is also associated with chronic bronchitis and silicosis, as well as a number of exposure to tobacco smoke, including early age of first use, duration, and cumulative exposure. Tumor and sputum samples are being examined for early markers of lung cancer. CONCLUSION: A cohort of occupationally-exposed tin miners with an extensive biologic specimen repository has been successfully established to simultaneously study the etiology and early detection of lung cancer.