beta-carotene and Laryngeal-Neoplasms

In recent intervention studies, beta-carotene failed to reduce or even increased the incidence of lung cancers in smokers. In the present investigation, the modifying effects of beta-carotene at various doses on the development of upper respiratory tract tumors were investigated in Syrian hamsters treated with diethylnitrosamine (DEN) and cigarette smoke. A total of 120 male 5-week-old hamsters were divided into 4 groups, each consisting of 30 animals. After a single subcutaneous (s.c.) injection of 100 mg/kg DEN, hamsters in groups 1-4 were respectively administered diets supplemented with beta-carotene at doses of 0.5%, 0.05%, 0.005% or 0% during experimental weeks 1 to 13, and simultaneously exposed to cigarette smoke. The duration of cigarette smoke exposure was 9 min twice a day, 5 days a week. Because of a marked reduction of body weight in group 1, the highest dose of beta-carotene was changed to 0.25% after 10 days. In all groups, epithelial hyperplasias and/or papillomas were induced in the larynx and trachea. However, the incidence and multiplicity of papillomas in group 1 were significantly (P < 0.05) lower than the group 4 values. Moreover, the beta-carotene treatments significantly (P < 0.05 or 0.01) reduced both the incidence and multiplicity of hyperplasias in a dose-dependent manner. The levels of retinol and beta-carotene in the serum, and the retinol level in the liver, were also elevated with dose dependence. Our results thus indicate that beta-carotene inhibits tumorigenesis, even at the high dose of 0.25%, under the present experimental conditions.

Topics: Animals; Anticarcinogenic Agents; Antioxidants; beta Carotene; Cricetinae; Diethylnitrosamine; DNA Damage; Laryngeal Neoplasms; Male; Mesocricetus; Nicotiana; Plants, Toxic; Smoke; Tracheal Neoplasms

We conducted a follow-up study of 380 incident cases of cancer of the oral cavity, pharynx, or larynx, who had been included in a previous case-control study. Information pertaining to potential risk factors, clinical characteristics, and evolution of the tumor (vital status, metastases, and second primary tumors) was obtained. From a multivariate proportional hazard model including terms for risk factors and clinical variables, the incidence of metachronous second primary tumors occurring in the head and neck was positively associated with employment as a farmer as opposed to white collar (hazard ratio [HR] = 3.3) and with tobacco smoking before first tumor diagnosis (HR = 4.3 for heavy versus never or very light smoker). The risk of second primary tumor decreased with increasing dietary "beta-carotene" intake (HR = 0.4 for high versus low intake in tertiles). Less differentiated first primary tumors were followed more frequently by second tumors as compared to grade 1 tumors. The incidence of metastases was not associated with etiological factors of the first tumor, but with stage.

Topics: Adult; Aged; Aged, 80 and over; Alcohol Drinking; Antineoplastic Agents; beta Carotene; Carotenoids; Case-Control Studies; Cohort Studies; Female; Follow-Up Studies; Humans; Laryngeal Neoplasms; Male; Middle Aged; Mouth Neoplasms; Neoplasm Metastasis; Neoplasms, Second Primary; Occupations; Pharyngeal Neoplasms; Risk Factors; Smoking

Using data from a case-control study conducted between 1986 and 1992 in Northern Italy on 367 cases of laryngeal cancers (350 men and 17 women) and 1931 hospital controls (1373 men and 558 women), we estimated the relative risks (RR) and the population attributable risks (AR) for laryngeal cancer in relation to tobacco and alcohol consumption and a diet containing little fresh fruit and vegetables (low beta-carotene intake). In men, the RR and their 95% confidence interval (CI), derived from multiple logistic regression, including terms for center, age, and education, plus, simultaneously, tobacco, alcohol, and beta-carotene) were 3.3 (95% CI, 1.9 to 5.5) for ex- or moderate smokers (< 15 cigarettes/day) and 8.8 (95% CI, 5.2 to 14.8) for heavy current smokers compared to never smokers; the RR were 1.5 (95% CI, 1.0 to 2.2) for drinkers of 6 to < 8 alcoholic drinks/day and 2.2 (95% CI, 1.6 to 3.0) for drinkers of 8 or more drinks/day compared to teetotallers or moderate drinkers; with respect to carotene intake the RR were 1.4 (95% CI, 1.0 to 2.0) for the intermediate tertile and 1.8 (95% CI, 1.3 to 2.5) for the lowest tertile, as compared to the highest tertile of intake. AR were estimated assuming a multiplicative model: the single factor with the largest AR was smoking, which accounted for about 77% of laryngeal cancers in men; alcohol intake explained about 25% of cases, low beta-carotene intake accounted for about 18% of cases, and together the three factors were responsible for about 86% of laryngeal cancers in men.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Aged; Alcohol Drinking; beta Carotene; Carotenoids; Case-Control Studies; Cross-Cultural Comparison; Cross-Sectional Studies; Feeding Behavior; Female; Humans; Incidence; Italy; Laryngeal Neoplasms; Male; Middle Aged; Risk Factors; Smoking

Serum vitamin A concentrations were measured in 22 patients with laryngeal cancer and found to be significantly lower than those of patients of similar age with either nonmalignant laryngeal or other than laryngeal diseases. The levels of vitamin A in the patients with laryngeal cancer, but not in the controls, significantly correlated with serum concentrations of retinol-binding protein (RBP) and zinc. It is suggested that low levels of zinc might reduce the synthesis of RBP and thus reduce the mobilization of vitamin A from the liver stores.

Topics: Aged; beta Carotene; Carotenoids; Copper; Female; Humans; Laryngeal Neoplasms; Male; Middle Aged; Neoplasm Staging; Retinol-Binding Proteins; Serum Albumin; Statistics as Topic; Vitamin A; Vitamin E; Zinc

Many investigations suggested relations between fat soluble vitamin levels in blood and incidence of cancer. These studies are concerning both therapeutical efficiency of vitamins intake, seric levels and cancer risk, and the supposed correlation between blood fat soluble vitamin levels and the cancer localization. The purpose of the present study was to investigate whether the alterations of fat soluble vitamin levels (A-vitamin, beta-carotene and alpha-tocopherol) were correlated not only to carcinogenic processes but also to the localizations of their developments. In a former article, we have found that an abnormal ketone derivative of D3 vitamin (1-keto-24-methyl-25-hydroxycholecalciferol) or carcinomedin was present in the serum of all cancer patients and absent in that of healthy control subjects. Serum levels of the four above substances were determined in 1068 subjects suffering from differently localized cancers and in 880 healthy subjects. A statistical multidimensional analysis of data led a separate five groups of cancer types (p less than 0.001). Within each group alterations of vitamin spectra, compared to controls, were identical; between groups they were significantly different. These groups were: anal and intestinal cancer; pancreatic, hepatic, oesophageal and gastric cancer; laryngeal and lung cancer; uro-genital and breast cancer; brain cancer. All these groups are statistically different from the reference one (p less than 0.001). This grouping roughly corresponds to the embryologic origin of affected organs. This suggests that carcinogenesis may alter fat soluble vitamin metabolism, specifically in various forms of cancer, or these alterations of vitamin metabolism are in some way involved in the carcinogenic process.

Topics: Adult; beta Carotene; Breast Neoplasms; Calcitriol; Carotenoids; Digestive System Neoplasms; Female; Humans; Intestinal Neoplasms; Laryngeal Neoplasms; Lung Neoplasms; Male; Middle Aged; Neoplasms; Nervous System Neoplasms; Urogenital Neoplasms; Vitamin A; Vitamin E