beta-carotene and Carcinoma--Basal-Cell

'Keratinocyte cancer' is now the preferred term for the most commonly identified skin cancers basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC), which were previously commonly categorised as non-melanoma skin cancers (NMSC). Keratinocyte cancer (KC) represents about 95% of malignant skin tumours. Lifestyle changes have led to increased exposure to the sun, which has, in turn, led to a significant increase of new cases of KC, with a worldwide annual incidence of between 3% and 8%. The successful use of preventive measures could mean a significant reduction in the resources used by health systems, compared with the high cost of the treatment of these conditions. At present, there is no information about the quality of the evidence for the use of these sun protection strategies with an assessment of their benefits and risks.. To assess the effects of sun protection strategies (i.e. sunscreen and barrier methods) for preventing keratinocyte cancer (that is, basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) of the skin) in the general population.. We searched the following databases up to May 2016: the Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, and LILACS. We also searched five trial registries and the bibliographies of included studies for further references to relevant trials.. We included randomised controlled clinical trials (RCTs) of preventive strategies for keratinocyte cancer, such as physical barriers and sunscreens, in the general population (children and adults), which may provide information about benefits and adverse events related to the use of solar protection measures. We did not include trials focused on educational strategies to prevent KC or preventive strategies in high-risk groups. Our prespecified primary outcomes were BCC or cSCC confirmed clinically or by histopathology at any follow-up and adverse events.. Two review authors independently selected studies for eligibility using Early Review Organizing Software (EROS). Similarly, two review authors independently used predesigned data collection forms to extract information from the original study reports about the participants, methods of randomisation, blinding, comparisons of interest, number of participants originally randomised by arm, follow-up losses, and outcomes, and they assessed the risk of bias. We resolved any disagreement by consulting a third author and contacted trial investigators of identified trials to obtain additional information. We used standard methodological procedures expected by Cochrane.. We included one RCT (factorial design) that randomised 1621 participants.This study compared the daily application of sunscreen compared with discretionary use of sunscreen, with or without beta-carotene administration, in the general population. The study was undertaken in Australia; 55.2% of participants had fair skin, and they were monitored for 4.5 years for new cases of BCC or cSCC assessed by histopathology. We found this study to be at low risk of bias for domains such as allocation, blinding, and incomplete outcome data. However, we found multiple unclear risks related to other biases, including an unclear assessment of possible interactions between the effects of the different interventions evaluated (that is, sunscreen and beta-carotene). We found no difference in terms of the number of participants developing BCC (n = 1621; risk ratio (RR) 1.03, 95% confidence interval (CI) 0.74 to 1.43) or cSCC (n = 1621; RR 0.88, 95% CI 0.50 to 1.54) when comparing daily application of sunscreen with discretionary use, even when analyses were restricted to groups without beta-carotene supplementation. This evidence was of low quality, which means that there is some certainty that future studies may alter our confidence in this evidence.We reported adverse events in a narrative way and included skin irritation or contact allergy.We identified no studies that evaluated other sun protection measures, such as the use of sun-protective clothing, sunglasses, or hats, or seeking the shade when outdoors.. In this review, we assessed the effect of solar protection in preventing the occurrence of new cases of keratinocyte cancer. We only found one study that was suitable for inclusion. This was a study of sunscreens, so we were unable to assess any other forms of sun protection. The study addressed our prespecified primary outcomes, but not most of our secondary outcomes. We were unable to demonstrate from the available evidence whether sunscreen was effective for the prevention of basal cell carcinoma (BCC) or cutaneous squamous cell carcinoma (cSCC).Our certainty in the evidence was low because there was a lack of histopathological confirmation of BCC or cSCC in a significant percentage of cases. Amongst other sources of bias, it was not clear whether the study authors had assessed any interaction effects between the sunscreen and beta-carotene interventions. We think that further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.

Topics: Adult; Australia; beta Carotene; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Child; Humans; Neoplasms, Radiation-Induced; Randomized Controlled Trials as Topic; Skin Neoplasms; Sunlight; Sunscreening Agents; Ultraviolet Rays; Vitamins

Topics: Antioxidants; beta Carotene; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Combined Modality Therapy; Cryotherapy; Humans; Retinoids; Skin Neoplasms

Topics: Aging; Animals; Antioxidants; beta Carotene; Carcinogens; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Carotenoids; DNA; Female; Geography; Humans; Male; Melanocytes; Melanoma; Neoplasms, Radiation-Induced; Pyrimidine Dimers; Sex Factors; Skin Neoplasms; Ultraviolet Rays; Vitamin A

Topics: Adult; Aged; Aged, 80 and over; Antioxidants; beta Carotene; Carcinoma, Basal Cell; Case-Control Studies; Dietary Supplements; Humans; Male; Middle Aged; Neoplasms, Squamous Cell; Oxidative Stress; Risk Factors; Skin Neoplasms; Tocopherols; Vitamin A; Vitamin E

Although basic research provides plausible mechanisms for benefits of beta carotene supplementation on nonmelanoma skin cancer (NMSC) primarily consisting of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), observational studies are inconsistent. Randomized trial data are limited to 1 trial of secondary prevention that showed no effect of beta carotene on the incidence of NMSC after 5 years.. To test whether supplementation with beta carotene reduces the risk for development of a first NMSC, including BCC and SCC.. Randomized, double-blind, placebo-controlled trial with 12 years of beta carotene supplementation and follow-up.. Physicians' Health Study in the United States.. Apparently healthy male physicians aged 40 to 84 years in 1982 (N = 22 071).. Beta carotene, 50 mg, on alternate days.. Relative risk (RR) and 95% confidence interval (CI) for a first NMSC, BCC, and SCC.. After adjusting for age and randomized aspirin assignment, there was no effect of beta carotene on the incidence of a first NMSC (RR, 0.98; 95% CI, 0.92-1.05), BCC (RR, 0.99; 95% CI, 0.92-1.06), or SCC (RR, 0.97; 95% CI, 0.84-1.13). There was also no significant evidence of beneficial or harmful effects of beta carotene on NMSC by smoking status (current, past, or never).. This large-scale, randomized, primary prevention trial among apparently healthy well-nourished men indicates that an average of 12 years of supplementation with beta carotene does not affect the development of a first NMSC, including BCC and SCC.

Topics: Adult; Aged; Aged, 80 and over; Antioxidants; beta Carotene; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Cohort Studies; Dietary Supplements; Double-Blind Method; Follow-Up Studies; Humans; Incidence; Male; Middle Aged; Primary Prevention; Skin Neoplasms; United States

The use of sunscreens on the skin can prevent sunburn but whether long-term use can prevent skin cancer is not known. Also, there is evidence that oral betacarotene supplementation lowers skin-cancer rates in animals, but there is limited evidence of its effect in human beings.. In a community-based randomised trial with a 2 by 2 factorial design, individuals were assigned to four treatment groups: daily application of a sun protection factor 15-plus sunscreen to the head, neck, arms, and hands, and betacarotene supplementation (30 mg per day); sunscreen plus placebo tablets; betacarotene only; or placebo only. Participants were 1621 residents of Nambour in southeast Queensland, Australia. The endpoints after 4.5 years of follow-up were the incidence of basal-cell and squamous-cell carcinomas both in terms of people treated for newly diagnosed disease and in terms of the numbers of tumours that occurred. Analysis of the effect of sunscreen was based only on skin cancers that developed on sites of daily application. All analyses were by intention to treat.. 1383 participants underwent full skin examination by a dermatologist in the follow-up period. 250 of them developed 758 new skin cancers during the follow-up period. There were no significant differences in the incidence of first new skin cancers between groups randomly assigned daily sunscreen and no daily sunscreen (basal-cell carcinoma 2588 vs 2509 per 100,000; rate ratio 1.03 [95% CI 0.73-1.46]; squamous-cell carcinoma 876 vs 996 per 100,000; rate ratio 0.88 [0.50-1.56]). Similarly, there was no significant difference between the betacarotene and placebo groups in incidence of either cancer (basal-cell carcinoma 3954 vs 3806 per 100,000; 1.04 [0.73-1.27]; squamous-cell carcinoma 1508 vs 1146 per 100,000; 1.35 [0.84-2.19]). In terms of the number of tumours, there was no effect on incidence of basal-cell carcinoma by sunscreen use or by betacarotene but the incidence of squamous-cell carcinoma was significantly lower in the sunscreen group than in the no daily sunscreen group (1115 vs 1832 per 100,000; 0.61 [0.46-0.81]).. There was no harmful effect of daily use of sunscreen in this medium-term study. Cutaneous squamous-cell carcinoma, but not basal-cell carcinoma seems to be amenable to prevention through the routine use of sunscreen by adults for 4.5 years. There was no beneficial or harmful effect on the rates of either type of skin cancer, as a result of betacarotene supplementation.

Topics: Adult; Aged; beta Carotene; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Drug Therapy, Combination; Female; Follow-Up Studies; Humans; Male; Middle Aged; Neoplasms, Radiation-Induced; Queensland; Skin Neoplasms; Sunscreening Agents

Epidemiological studies suggest that individuals with basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of the skin are more likely to develop other malignancies; however, the factors responsible for this are unknown. To clarify the risk of other cancers following the occurrence of BCC and SCC, we followed participants in a multicenter skin cancer prevention trial for subsequent malignancies. The study group consisted of 1805 BCC and SCC patients who had enrolled in a trial testing the efficacy of oral beta-carotene. Medical confirmation was sought for all cancers (other than BCC or SCC), which were reported by participants or their next-of-kin over a follow-up period of 10 years. We computed the rate ratio (RR) and 95% confidence interval (CI) of time to first new, primary cancer in relation to history of BCC and SCC, using a proportional hazards model. A total of 235 participants had a new primary invasive cancer during 13,887 person-years of follow up. The risk of other cancers was modestly elevated in patients with one or more previous SCCs compared with those who only had a history of BCC (adjusted RR, 1.37; 95% CI, 0.91-2.07). Risk of other cancers also appeared to be increased among those who had multiple prior BCCs relative to those who had only one prior BCC (adjusted RR, 1.21; 95% CI, 0.91-1.61). Further adjustment for smoking history, Quetelet index, radiotherapy, extent of actinic skin damage, treatment assignment, or baseline beta-carotene concentrations did not appreciably alter the results. Cancer of the respiratory system was most strongly related to previous SCC or multiple BCC [RRs (95% CI), 2.20 (1.05-4.62) and 2.34 (1.14-4.83), respectively]. Our data suggest that unidentified exposures or inherited risk factors may play a common etiological role in the pathogenesis of nonmelanoma skin cancer and other cancers, especially respiratory cancers, although larger studies would be necessary to exclude the role of chance in these findings.

Topics: Aged; Anticarcinogenic Agents; beta Carotene; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Female; Humans; Incidence; Male; Middle Aged; Neoplasms, Second Primary; Proportional Hazards Models; Risk Factors; SEER Program; Skin Neoplasms

Topics: Antioxidants; beta Carotene; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Combined Modality Therapy; Cryotherapy; Humans; Retinoids; Skin Neoplasms

The Nambour Skin Cancer and Actinic Eye Disease Prevention Trial (the Nambour Trial) is a field trial conducted in an unselected adult population in Australia. Using a randomized 2 x 2 factorial design, the principal aim is to evaluate whether regular use of high-protection sunscreen and/or dietary supplementation with beta-carotene (30 mg daily) can alter the incidence rates of basal cell carcinomas and squamous cell carcinomas of the skin over a minimum follow-up time of 4.5 years. Changes in the incidence of solar keratoses and actinic eye disease and the rate of photoaging after intervention will also be investigated. In 1992, 1626 participants between the ages of 25 and 75 years were enrolled, all of whom had been randomly selected from residents of the southeastern Queensland township of Nambour for an earlier skin cancer prevalence survey. This paper describes the background to the trial and its design, with respect to evaluation of effects on actinic skin disease, and documents the baseline characteristics of participants recruited into the Nambour Trial.

Topics: Adult; Aged; beta Carotene; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Carotenoids; Cataract; Female; Humans; Male; Middle Aged; Patient Compliance; Skin Neoplasms; Sunscreening Agents; Ultraviolet Rays

Topics: Adult; beta Carotene; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Carotenoids; Diet; Double-Blind Method; Female; Follow-Up Studies; Humans; Life Style; Male; Middle Aged; Risk Factors; Sex Factors; Skin Neoplasms; Smoking; Surveys and Questionnaires; United States

The primary aims of this study were to assess risk of subsequent basal and squamous cell skin cancer among patients with a prior history of these tumors and to examine these risks in relation to patient characteristics and life-style factors.. Follow-up of participants in a randomized trial of betacarotene as a possible skin cancer preventive agent.. Clinical centers in Los Angeles, Calif, San Francisco, Calif, Minneapolis, Minn, and Hanover, NH.. Patients (n = 1805) who were diagnosed as having a basal or squamous cell skin cancer between January 1980 and February 1986 and were free of skin cancer at study entry.. Time from study entry to first new occurrence of basal and squamous cell skin cancer.. The estimated risk of developing one or more new skin cancers was 35% at 3 years and 50% at 5 years. New skin cancers tended to be of the same cell type as the previous skin cancers. For both basal and squamous cell skin cancer, risk was higher among patients who were male, were over the age of 60 years, had more prior skin cancers, had severe actinic skin damage, or who burned easily with sun exposure. Compared with those who had never smoked, the rate of subsequent squamous cell skin cancer was higher among current smokers (rate ratio, 2.01; 95% confidence interval, 1.21 to 3.34) and former smokers (rate ratio, 1.62; 95% confidence interval, 1.07 to 2.47) and increased with both duration and amount smoked. There was no clear relationship between smoking and basal cell skin cancer; the rate appeared lower among heavy smokers but was unrelated to duration of smoking.. Persons with a prior nonmelanoma skin cancer had a substantial 5-year risk of developing another tumor of the same histologic type. Number of previous skin cancers, solar damage, and skin sensitivity to sun exposure were particularly related to this risk. The increased risk of squamous cell skin cancer associated with cigarette smoking merits further study.

Topics: Adult; Aged; Aged, 80 and over; beta Carotene; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Carotenoids; Female; Follow-Up Studies; Humans; Male; Middle Aged; Neoplasm Recurrence, Local; Probability; Risk Factors; Sex Factors; Skin Neoplasms; Smoking

Previous studies suggest that chronic oral administration of retinol and other retinoids causes elevation of plasma triglyceride concentrations. The effects of chronic oral administration of beta-carotene, a carotenoid partially metabolized to retinol, on plasma lipid concentrations have not been well studied; therefore, we studied 61 subjects over 12 mo while they were enrolled in a skin-cancer-prevention study in which patients were randomly assigned to receive either placebo (n = 30) or 50 mg beta-carotene/d orally (n = 31). At study entry and 1 y later, fasting blood samples were obtained for measurement of triglycerides, total cholesterol, HDL cholesterol, retinol, and beta-carotene. Retinol concentrations changed minimally in both groups; beta-carotene concentration increased an average of 12.1 +/- 47 nmol/L in the placebo group and 4279 +/- 657 nmol/L in the active-treatment group. Both groups experienced similar small increases in triglyceride and total cholesterol concentrations and small decreases in HDL cholesterol. Daily oral administration of 50 mg beta-carotene/d did not affect plasma lipid concentrations.

Topics: Administration, Oral; beta Carotene; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Carotenoids; Cholesterol; Cholesterol, HDL; Humans; Lipids; Skin Neoplasms; Triglycerides; Vitamin A

Beta carotene has been associated with a decreased risk of human cancer in many studies employing dietary questionnaires or blood measurements, and it has had protective effects in some animal models of carcinogenesis.. We tested the possible cancer-preventing effects of beta carotene by randomly assigning 1805 patients who had had a recent nonmelanoma skin cancer to receive either 50 mg of beta carotene or placebo per day and by conducting annual skin examinations to determine the occurrence of new nonmelanoma skin cancer.. Adherence to the prescribed treatment was good, and after one year the actively treated group's median plasma beta carotene level (3021 nmol per liter) was much higher than that of the control group (354 nmol per liter). After five years of follow-up, however, there was no difference between the groups in the rate of occurrence of the first new nonmelanoma skin cancer (relative rate, 1.05; 95 percent confidence interval, 0.91 to 1.22). In subgroup analyses, active treatment showed no efficacy either in the patients whose initial plasma beta carotene level was in the lowest quartile or in those who currently smoked. There was also no significant difference between treated and control groups in the mean number of new nonmelanoma skin cancers per patient-year.. In persons with a previous nonmelanoma skin cancer, treatment with beta carotene does not reduce the occurrence of new skin cancers over a five-year period of treatment and observation.

Topics: Aged; beta Carotene; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Carotenoids; Drug Evaluation; Female; Follow-Up Studies; Humans; Male; Patient Compliance; Randomized Controlled Trials as Topic; Recurrence; Skin Neoplasms

Low-molecular-weight antioxidants are some of the most efficient agents of the skin defense mechanism against environmental factors, such as cosmic rays, smoke, and pollutants. The total skin concentrations of hydrophilic ascorbic and uric acids, as well as lipophilic α-tocopherol, β-carotene, and ubiquinol-10 antioxidants were determined by an HPLC-EC detector from 18 biopsies of human nonmelanoma skin carcinomas and 18 biopsies from skin areas adjacent to carcinomas. No significant differences in the concentrations of lipophilic antioxidants in both carcinomas and normal-looking skin areas adjacent to carcinomas were observed. On the contrary, ascorbic and uric acid concentrations were found to be 18 and 36% lower in carcinomas than in normal-looking skin areas, respectively. No statistical significance was observed between antioxidant concentrations and age, sex, phototype, profession, site of tumor, frequency, and time of UV light exposure either. Accordingly the antioxidant concentrations in both cancerous skin and adjacent normal-looking areas were found to be much higher than in normal skin, in contrast to literature data.

Topics: Adult; Aged; Aged, 80 and over; alpha-Tocopherol; Antioxidants; Ascorbic Acid; beta Carotene; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Female; Humans; Male; Middle Aged; Molecular Weight; Skin; Skin Neoplasms; Ubiquinone; Uric Acid

Analysis of longitudinal data with excessive zeros has gained increasing attention in recent years; however, current approaches to the analysis of longitudinal data with excessive zeros have primarily focused on balanced data. Dropouts are common in longitudinal studies; therefore, the analysis of the resulting unbalanced data is complicated by the missing mechanism. Our study is motivated by the analysis of longitudinal skin cancer count data presented by Greenberg, Baron, Stukel, Stevens, Mandel, Spencer, Elias, Lowe, Nierenberg, Bayrd, Vance, Freeman, Clendenning, Kwan, and the Skin Cancer Prevention Study Group[New England Journal of Medicine 323, 789-795]. The data consist of a large number of zero responses (83% of the observations) as well as a substantial amount of dropout (about 52% of the observations). To account for both excessive zeros and dropout patterns, we propose a pattern-mixture zero-inflated model with compound Poisson random effects for the unbalanced longitudinal skin cancer data. We also incorporate an autoregressive of order 1 correlation structure in the model to capture longitudinal correlation of the count responses. A quasi-likelihood approach has been developed in the estimation of our model. We illustrated the method with analysis of the longitudinal skin cancer data.

Topics: Aged; Antioxidants; beta Carotene; Bias; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Carotenoids; Data Interpretation, Statistical; Drug Evaluation; Female; Follow-Up Studies; Humans; Incidence; Longitudinal Studies; Male; Patient Compliance; Randomized Controlled Trials as Topic; Recurrence; Skin Neoplasms

Experimental studies have consistently shown a protective effect of nonsteroidal antiinflammatory drugs (NSAIDs) against nonmelanoma skin cancers (NMSC). However, little human epidemiological research has been done in this regard. We used data from the Skin Cancer Chemoprevention Study to explore the association of NSAID use and with the risk of basal-cell carcinoma (BCC) and squamous-cell carcinoma (SCC). 1,805 subjects with a recent history of NMSC were randomized to placebo or 50 mg of daily beta-carotene. Participants were asked about their use of over-the-counter and prescription medications at baseline and every 4 months during the trial. Skin follow-up examinations were scheduled annually with a study dermatologist; confirmed lesions were the endpoints in the study. We used a risk set approach to the analysis of grouped times survival data and unconditional logistic regression to compute odds ratios [ORs] for various exposures to NSAIDs. The use of NSAIDs was reported in over 50% of questionnaires. For BCC, NSAIDs exhibited a weak protective effect in crude analyses, which attenuated markedly after adjustment. For SCC, the use of NSAIDs in the year previous to diagnosis reduced the odds by almost 30% (adjusted OR=0.71, 95% CI 0.48-1.04). When we accounted for frequency of use, results for BCC were not striking, and there were inconsistent suggestions of an inverse association with SCC. There were some indications of a modest, nonsignificant reduction on the number of BCCs and SCCs with NSAID use. Our data suggest a weak and inconsistent chemopreventive effect of NSAIDs on BCC and SCC.

Topics: Aged; Anti-Inflammatory Agents, Non-Steroidal; Anticarcinogenic Agents; Antioxidants; beta Carotene; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Female; Follow-Up Studies; Humans; Male; Middle Aged; Neoplasm Recurrence, Local; Odds Ratio; Randomized Controlled Trials as Topic; Regression Analysis; Risk Factors; Skin Neoplasms; Surveys and Questionnaires

Topics: Adult; Aged; Antioxidants; beta Carotene; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Dietary Supplements; Female; Humans; Male; Middle Aged; Randomized Controlled Trials as Topic; Skin Neoplasms; Sunscreening Agents

A number of lifestyle factors are important in the etiology of basal cell carcinoma. Previous studies have investigated smoking, alcohol, diet, and sun exposure as possible contributing factors. No previous studies have investigated case-controlled lifestyle influences in basal cell carcinomas referred for Mohs micrographic surgery.. Cases were obtained from Mohs-referred basal cell carcinoma patients. Matched controls were selected from a busy dermatology clinic. The only criteria for selection of controls was never having had cancer previously. Cases and controls were surveyed regarding lifestyle characteristics.. Forty-six age, sex, and skintype-matched controls were compared. Sun exposure, alcohol, and smoking were not significant factors. Dietary fat, fiber, and the vitamins A, C, and beta carotene, as well as selenium showed important, but not significant differences. Caffeine consumption was higher in the cancer group.. Our findings agree with previously published studies in regard to antioxidant consumption as a protective factor for basal cell carcinoma. Caffeine consumption was higher in the cancer patients.

Topics: Aged; Alcohol Drinking; Ascorbic Acid; beta Carotene; Caffeine; Carcinoma, Basal Cell; Carotenoids; Case-Control Studies; Female; Humans; Life Style; Male; Middle Aged; Mohs Surgery; Risk Factors; Selenium; Skin Neoplasms; Smoking; Vitamin E

A case-control study was conducted in Melbourne, Australia of 88 consecutive males admitted for the surgical removal of a nonmelanocytic skin cancer (histologically confirmed basal cell carcinoma and squamous cell carcinoma) and of 88 male control patients admitted for small elective surgical procedures. In both cases and controls, previous diet, alcohol consumption, and smoking habit were investigated and serum beta-carotene and vitamin A levels were measured. A statistically significant inverse relationship was found between the risk of skin cancer and a high intake of fish (p = 0.05); vegetables in general (p < 0.001); beans, lentils, or peas (p < 0.001), carrots, silverbeet (Swiss chard), or pumpkin (p < 0.001); cruciferous vegetables (cabbage, brussel sprouts, or broccoli) (p < 0.001); and beta-carotene- and vitamin C-containing foods (p = 0.004). Cases had a lower mean serum level of beta-carotene (p < 0.001) and vitamin A (p = 0.02) than controls. The incidence of skin cancer in the study was inversely related to the level of serum beta-carotene (p < 0.0001). The correlation coefficient between dietary beta-carotene/vitamin C and serum beta-carotene was 0.22 (p = 0.04). Smoking and alcohol consumption showed no statistically significant association with the risk of nonmelanocytic skin cancer. The results were similar for both cell types. A high intake of vegetables including cruciferous vegetables, beta-carotene- and vitamin C-containing foods, and fish appears to be protective for nonmelanocytic skin cancer, and this deserves further study, as does the possible etiologic relevance of the low serum levels of beta-carotene and vitamin A.

Topics: Aged; Alcohol Drinking; beta Carotene; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Carotenoids; Case-Control Studies; Diet; Humans; Incidence; Male; Middle Aged; Skin Neoplasms; Smoking; Vitamin A

Topics: Anticarcinogenic Agents; beta Carotene; Carcinoma, Basal Cell; Carotenoids; Humans; Isotretinoin; Skin Neoplasms

Topics: beta Carotene; Canthaxanthin; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Carotenoids; Child; Child, Preschool; Drug Combinations; Drug Therapy, Combination; Etretinate; Humans; Keratosis; Male; Skin Neoplasms; Xeroderma Pigmentosum