ascorbic-acid and Carcinoma--Small-Cell

Despite the unexpected results from the beta-Carotene and Retinol Efficacy Trial (CARET) and similar supplementation trials showing that supplementation with beta-carotene increased, rather than decreased, lung cancer incidence, considerable interest remains in investigating how other compounds in fruits and vegetables may affect lung cancer risk. We used data from 14,120 CARET participants who completed food frequency questionnaires to examine associations of diet with lung cancer risk. After 12 years of follow-up (1989-2001), 742 participants developed lung cancer. We used Cox proportional hazards models to estimate multivariate relative risks (RRs) and 95% confidence intervals (CIs). Analyses were controlled for smoking, asbestos exposure, and other covariates. Analyses of specific botanical groups were also controlled for total fruit and vegetable intake. All models were stratified by CARET treatment arm, and all statistical tests were two-sided. Statistically significant associations of fruit and vegetable intake with lower lung cancer risk were restricted to the CARET placebo arm. The RR for highest versus lowest quintile of total fruit consumption in the placebo arm was 0.56 (95% CI, 0.39-0.81) with a two-sided P for trend = 0.003. Two specific botanical groups were associated with reduced risk of lung cancer. Compared with the lowest quintile of rosaceae fruit consumption, placebo participants in the top quintile had a RR of 0.63 (95% CI, 0.42-0.94; P for trend = 0.02); for cruciferae vegetables, the RR was 0.68 (95% CI, 0.45-1.04; P for trend = 0.01). We did not observe any statistically significant associations of fruit and vegetable intake with lung cancer risk among participants randomized to receive the CARET supplements (30 mg of beta-carotene and 25,000 IU of retinyl palmitate). This report provides evidence that plant foods have an important preventive influence in a population at high risk for lung cancer. However, persons who use beta-carotene supplements do not benefit from the protective compounds in plant foods.

Topics: Aged; Anticarcinogenic Agents; Antioxidants; Ascorbic Acid; beta Carotene; Carcinoma, Small Cell; Double-Blind Method; Feeding Behavior; Female; Follow-Up Studies; Fruit; Humans; Lung Neoplasms; Male; Middle Aged; Placebos; Risk Factors; Statistics as Topic; Treatment Outcome; Vegetables; Vitamin A

Selenium has been suggested to be anticarcinogenic and to play a role in the cellular defense against oxidative stress. The association between toenail selenium (a marker of long-term selenium status) and lung cancer was investigated in a cohort study of diet and cancer that started in 1986 among 120,852 Dutch men and women aged 55-69 years. After 3.3 years of follow-up, 550 incident cases of lung carcinoma were detected. Toenail selenium data were available for 370 lung cancer cases and 2459 members of a randomly selected subcohort. The rate ratio of lung cancer for subjects in the highest compared to the lowest quintile of toenail selenium, after controlling for age, gender, smoking, and education, was 0.50 (95% confidence interval, 0.30-0.81), with a significant inverse trend across quintiles (P = 0.006). The protective effect of selenium was concentrated in subjects with a relatively low dietary intake of beta-carotene or vitamin C. The rate ratio in the highest compared to the lowest quintile of selenium was 0.45 in the low beta-carotene group (95% confidence interval, 0.22-0.92; trend P = 0.028) and 0.36 in the low vitamin C group (95% confidence interval, 0.17-0.75; trend P < 0.001). The results of this study support an inverse association between selenium status and lung cancer and suggest a modification of the effect of selenium by the antioxidants beta-carotene and vitamin C.

Topics: Adenocarcinoma; Age Factors; Aged; Ascorbic Acid; beta Carotene; Carcinoma; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Carotenoids; Cohort Studies; Education; Feeding Behavior; Female; Follow-Up Studies; Humans; Incidence; Lung Neoplasms; Male; Middle Aged; Nails; Netherlands; Prospective Studies; Risk Factors; Selenium; Sex Factors; Smoking; Surveys and Questionnaires; Time Factors; Toes; Vitamin A

A case-control study was conducted based on 427 white males with lung cancer of the squamous, small cell, and adenocarcinoma histologic subtypes and 1,094 white male controls admitted to Roswell Park Memorial Institute between the years 1957 and 1965. The relation between selected dietary factors and lung cancer risk was examined for each histologic subtype while controlling for past cigarette use. Dietary vitamin A was found to be negatively associated with risk for squamous cell and small cell carcinoma, but not for adenocarcinoma of the lung. No significant association was observed, however, between dietary vitamin C, fats, or fiber and any of the lung cancer subtypes. These results suggest that the apparent protective effect of vitamin A in lung cancer may be histologic type-specific.

Topics: Adenocarcinoma; Adult; Aged; Alcohol Drinking; Ascorbic Acid; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Diet; Dietary Fats; Dietary Fiber; Humans; Lung Neoplasms; Male; Middle Aged; Risk; Smoking; Vitamin A

Three cases are described, 2 of Hodgkin's disease and a further case of bronchial carcinoma, where high dosage ascorbic acid treatment appeared to be associated with the development of potentially dangerous symptoms. It is suggested that mega ascorbic acid therapy should be given with caution in malignant disease, with a slow build-up over several days to high levels of dosage.

Topics: Adult; Aged; Animals; Antineoplastic Agents; Ascorbic Acid; Bronchial Neoplasms; Carcinoma, Small Cell; Dyspnea; Fever; Hodgkin Disease; Humans; Lung Neoplasms; Male; Neoplasms; Orthomolecular Therapy