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Query: UMLS:C0242379 (lung cancer)
 71,905 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have examined the relationship between diet and lung cancer in a case-control study of 982 cases of lung cancer and 1486 population controls in south-west England in which subjects were interviewed personally about their smoking habits and their consumption of foods and supplements rich in retinol or carotene. Analyses were performed for 15 dietary variables, including intake of pre-formed retinol and carotene. There were significant associations (P< 0.01) with lung cancer risk for 13 of the variables, eight of which remained after adjustment for smoking. When the 15 variables were considered simultaneously, independent significant associations remained for 5: pre-formed retinol (increased risk), and fish liver oil, vitamin pills, carrots and tomato sauce (decreased risk). It is unlikely that all five associations represent biological effects, or that they can all be explained by residual confounding by smoking, or by biases. We conclude that there is at least one as yet unidentified factor that is causally related to lung cancer risk and of considerable importance in terms of attributable risk in this population.
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PMID:Diet, smoking and lung cancer: a case-control study of 1000 cases and 1500 controls in South-West England. 1123 98

Recent intervention studies revealed that supplementation with retinoids resulted in a higher incidence of lung cancer. Recently the causal mechanism has begun to be clarified. We report here that retinol caused cellular oxidative stress and modulated superoxide dismutase, catalase and glutathione peroxidase activities. Retinol (7 microM) significantly increased TBARS, conjugated dienes, and hydroperoxide-initiated chemiluminescence in cultured Sertoli cells. In response to retinol treatment superoxide dismutase, catalase and glutathione peroxidase activities increased. TBARS content and catalase activities were decreased by a free radical scavenger. These findings suggest that retinol may induce oxidative stress and modulate antioxidant enzyme activities in Sertoli cells.
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PMID:Retinol supplementation induces oxidative stress and modulates antioxidant enzyme activities in rat sertoli cells. 1132 75

Oxidative DNA damage and antibodies to that damage have been implicated in lung, breast, and colorectal cancer. In this observational validation study, the relationship between anti-5-hydroxymethyl-2'-deoxyuridine (HMdU) autoantibody (aAb) and plasma micronutrients was assessed in 140 heavy smokers by ELISA. Anti-HMdU aAbs were 50% higher in women after adjustment for cigarettes/day (CPD; P = 0.002), although men smoked more and had higher plasma cotinine levels. The women reported taking more vitamin C (P < 0.005) and had higher plasma levels of alpha-carotene and beta-carotene (P < 0.001) and cryptoxanthin (P < 0.01) than men. Neither CPD nor cotinine was associated with aAb titers. Anti-HMdU aAbs were associated inversely with alpha-tocopherol (P = 0.10), retinol (P = 0.06), and age (P = 0.04) in women but not in men. In contrast to the men, women <or=50 years of age had significantly higher aAbs than those >50 years of age (P = 0.05). Given the same duration of exposure, women had higher anti-HMdU aAbs and also reached peak levels at a lower cumulative smoking exposure (30 years) compared with male smokers (40 years). Subjects smoked an average of 28.9 +/- 0.81 CPD and initiated smoking at 17.2 +/- 0.33 (SE) years of age. Therefore, smokers who reported smoking for 30 years were typically <50 years old. Women <or=50 years in the younger age group that smoked 21-30 years had significantly higher levels of aAbs than did men of the same age and smoking history (P = 0.012). Gender difference in aAbs was also evident in 29 persons who gave serial samples before and after quitting smoking (P < 0.028). In women, aAbs remained elevated for 14 months after smoking cessation but decreased significantly by 20.5 months (P < 0.032) by paired t tests. In men, aAbs increased with time since quitting smoking but not significantly. The finding of significantly elevated aAbs to oxidized DNA in females <or=50 compared with male smokers of the same age and exposure suggests a possible interaction with hormones (e.g., estrogens) and may explain a heightened risk of smoking-induced lung cancer in women compared with men.
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PMID:Gender differences in autoantibodies to oxidative DNA base damage in cigarette smokers. 1140 14

Higher blood levels of beta-carotene have been found to be associated with reduced risk of lung cancer, but large intervention trials have failed to demonstrate reduced lung cancer incidence after prolonged high-dose beta-carotene supplementation. Data on blood levels of specific carotenoids other than beta-carotene in relation to lung cancer are scarce. Little is known about the relationship between prediagnostic serum levels of carotenoids, retinol, and tocopherols, and risk of lung cancer especially in non-Western populations. Between January 1986 and September 1989, 18,244 men ages 45-64 years participated in a prospective study of diet and cancer in Shanghai, China. Information on tobacco smoking and other lifestyle factors was obtained through in-person interviews. A serum sample was collected from each study participant at baseline. During the first 12 years of follow-up, 209 lung cancer cases, excluding those diagnosed within 2 years of enrollment, were identified. For each cancer case, three cancer-free control subjects were randomly selected from the cohort and matched to the index case by age (within 2 years), month and year of blood sample collection, and neighborhood of residence. Serum concentrations of retinol, alpha- and gamma-tocopherols, and specific carotenoids including alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, and lutein/zeaxanthin were determined on the 209 cases and 622 matched controls by high-performance liquid chromatography methods. A high prediagnostic serum level of beta-cryptoxanthin was significantly associated with reduced risk of lung cancer; relative to the lowest quartile, the smoking-adjusted relative risks (95% confidence intervals) for the 2nd, 3rd, and 4th quartile categories were 0.72 (0.41-1.26), 0.42 (0.21-0.84), and 0.45 (0.22-0.92), respectively (P for trend = 0.02). Increased serum levels of other specific carotenoids including alpha-carotene, beta-carotene, lycopene, and lutein/zeaxanthin were related to reduced risk of lung cancer although the inverse associations were no longer statistically significant after adjustment for smoking. A statistically significant 37% reduction in risk of lung cancer was noted in smokers with above versus below median level of total carotenoids. Serum retinol levels showed a threshold effect on lung cancer risk. Compared with the lowest quartile (<40 microg/dl), the smoking-adjusted relative risk (95% confidence interval) was 0.60 (0.39-0.92) for men in the 2nd-4th quartiles of retinol values combined; no additional decrease in risk was observed between individuals from the 2nd to 4th quartiles. There were no associations between prediagnostic serum levels of alpha- and gamma-tocopherols and lung cancer (all Ps for trend > or =0.4). The present data indicate that higher prediagnostic serum levels of total carotenoids and beta-cryptoxanthin were associated with lower smoking-related lung cancer risk in middle-aged and older men in Shanghai, China. Low level of serum retinol (with a threshold effect) is associated with increased lung cancer risk in this oriental population.
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PMID:Prediagnostic levels of serum beta-cryptoxanthin and retinol predict smoking-related lung cancer risk in Shanghai, China. 1506 39

We evaluated the association between exposure to environmental tobacco smoke (ETS) from husbands who smoke and plasma levels of antioxidant vitamins among nonsmoking women. A total of 1249 women from four areas in Italy answered a self-administered questionnaire, reported their diets on a food frequency questionnaire, had a medical examination, and gave their blood for alpha and beta-carotene, retinol, L-ascorbic acid, alpha-tocopherol, and lycopene determinations. Urinary cotinine was used to evaluate the level of recent exposure to ETS. After adjusting for study center, age and education, we found no association between ETS exposure and daily nutrient intake of beta-carotene, retinol, L-ascorbic acid, and alpha-tocopherol. However, we found an inverse dose-response relationship between intensity of current husband's smoke and concentrations of plasma beta-carotene and L-ascorbic acid. The associations remained even after controlling for daily beta-carotene and vitamin C intake and for other potential confounders (vitamin supplementation, alcohol consumption, and body mass index). Moreover, when urinary cotinine was considered as the exposure variable, a significant inverse association with plasma beta-carotene was found. The findings may be of interest to explain the biological mechanism that link ETS exposure with lung cancer and ischemic heart diseases.
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PMID:Exposure to environmental tobacco smoke is associated with lower plasma beta-carotene levels among nonsmoking women married to a smoker. 1148 60

Lung cancer is the leading cause of cancer deaths in the United States and the world, with grim incidence and mortality figures underscoring the need for new approaches, such as chemoprevention, for controlling this disease. There have been definitive, randomized, controlled lung-cancer chemoprevention trials in the three chemoprevention trial settings: primary (healthy high-risk [eg, smokers]), secondary (premalignant lesions), and tertiary (prevention of second primary tumors in previously treated patients), all of which produced negative (either neutral or harmful) primary end point results. These trials established that lung cancer was not prevented by alpha-tocopherol, beta-carotene, retinol, retinyl palmitate, N-acetylcysteine, or isotretinoin in smokers. Provocative leads of the definitive trials include the possible activity of isotretinoin in never and former smokers and that of alpha-tocopherol in prostate cancer prevention. A major area of lung cancer research is molecular epidemiologic study of highest smoking-related risk based on the interactions between tobacco carcinogens, genetic polymorphisms involved in activating and detoxifying these carcinogens, and host-cell efficiency in monitoring and repairing tobacco carcinogen-DNA damage. The future of lung cancer chemoprevention will rely heavily on molecular studies of carcinogenesis and drug mechanisms to develop novel chemopreventive targets and drugs, risk markers, and surrogate end point biomarkers; new preclinical drug-testing models; novel imaging techniques for monitoring agent activity; and molecular epidemiologic risk models for identifying the highest-risk current and former smokers.
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PMID:Lung cancer chemoprevention: an integrated approach. 1156 Sep 78

Epidemiological studies have suggested that low levels of selenium are associated with a higher incidence of both lung and prostate cancer. We analyzed the selenium serum concentration in 356 Carotene and Retinol Efficacy Trial (CARET) participants who later developed lung cancer and 356 matched controls and in 235 prostate cancer cases and 456 matched controls. Serum samples were obtained a mean of 4.7 years before diagnosis for both tumor types. Controls were matched to cases by year of randomization, age, smoking status, treatment arm, exposure population (asbestos workers or cigarette smokers), and year of blood draw. In the control population (n = 820), significant predictors of low serum selenium concentration were current smoking status and East Coast locations of the study center. Overall, there was no significant difference in mean serum selenium in lung cancer cases versus controls (11.91 microg/dl versus 11.77 microg/dl) or prostate cancer cases versus controls (11.48 microg/dl versus 11.43 microg/dl). No statistically significant trend in odds ratio was seen across quartiles of serum selenium for lung cancer (P = 0.49) or prostate cancer (P = 0.69). In a subpopulation of 174 prostate cancer patients who had clinical and pathological staging material reviewed, there was no association between serum selenium and Gleason score or clinical or pathological stage. In the CARET population of current and former smokers consuming an ad libitum diet, the serum concentration of selenium was not a risk factor for either lung cancer or prostate cancer.
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PMID:Predictors of serum selenium in cigarette smokers and the lack of association with lung and prostate cancer risk. 1158 33

Recent intervention studies revealed that supplementation with retinoids resulted in a higher incidence of lung cancer. Recently the causal mechanism has begun to be clarified. We report here that retinol-induced oxidative stress is accompanied by cellular proliferation. Retinol (7 microM) significantly induced thiobarbituric acid reactive species (TBARS) formation, which was inhibited by trolox, superoxide dismutase, N-acetylcysteine and ethanol. This was accompanied by an increase in DNA synthesis and focus formation in cultured rat Sertoli cells. Antioxidants and ethanol inhibited retinol-induced DNA synthesis. Our findings suggest that retinol-induced oxidative stress was associated with cellular proliferation complementing our understanding of the significance of retinol supplementation in neoplastic transformation.
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PMID:Mitogenic signaling mediated by oxidants in retinol treated Sertoli cells. 1181 26

The objective of this preliminary uncontrolled study was twofold: First, to assess the feasibility of retinyl palmitate inhalation and second, to analyze the changes of metaplastic lesions of the respiratory epithelium (metaplasia or dysplasia) following retinyl palmitate inhalation. The response to a daily dose of 18.000 I.U. retinyl palmitate by inhalation over a period of 3 month was assessed in 11 subjects (9 smokers, 2 ex-smokers). Using white-light bronchoscopy combined with autofluorescence bronchoscopy, bronchial biopsies were taken before and after a 3 month-period. The biopsy samples were evaluated blind by a referee lung pathologist. The overall response rate (remission or partial remission) was 56% (95% CI 0.30 0.79; p<0.05). These data suggest that inhalation of retinyl esters could be a promising therapeutical approach for chemoprevention of lung cancer. Vitamin A; chemoprevention; lung cancer; squamous metaplasia; dysplasia; retinoids
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PMID:Inhalation of aerosolized vitamin a: reversibility of metaplasia and dysplasia of human respiratory epithelia -- a prospective pilot study. 1189 Nov 47

Findings from several beta-carotene supplementation trials were unexpected and conflicted with most observational studies. Carotenoids other than beta-carotene are found in a variety of fruits and vegetables and may play a role in this important malignancy, but previous findings regarding the five major carotenoids are inconsistent. The authors analyzed the associations between dietary beta-carotene, beta-carotene, lutein/zeaxanthin, lycopene, beta-cryptoxanthin, vitamin A, serum beta-carotene, and serum retinol and the lung cancer risk in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort of male smokers conducted in southwestern Finland between 1985 and 1993. Of the 27,084 male smokers aged 50-69 years who completed the 276-food item dietary questionnaire at baseline, 1,644 developed lung cancer during up to 14 years of follow-up. Cox proportional hazards models were used to estimate relative risks and 95% confidence intervals. Consumption of fruits and vegetables was associated with a lower lung cancer risk (relative risk = 0.73, 95% confidence interval: 0.62, 0.86, highest vs. lowest quintile). Lower risks of lung cancer were observed for the highest versus the lowest quintiles of lycopene (28%), lutein/zeaxanthin (17%), beta-cryptoxanthin (15%), total carotenoids (16%), serum beta-carotene (19%), and serum retinol (27%). These findings suggest that high fruit and vegetable consumption, particularly a diet rich in carotenoids, tomatoes, and tomato-based products, may reduce the risk of lung cancer.
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PMID:Dietary carotenoids, serum beta-carotene, and retinol and risk of lung cancer in the alpha-tocopherol, beta-carotene cohort study. 1222 1


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