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Earl G. Gross

Bio: Earl G. Gross is an academic researcher from United States Department of Veterans Affairs. The author has contributed to research in topics: Isotretinoin & Etretinate. The author has an hindex of 13, co-authored 15 publications receiving 3665 citations.

Papers
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Journal ArticleDOI
25 Dec 1996-JAMA
TL;DR: Results from secondary end-point analyses support the hypothesis that supplemental selenium may reduce the incidence of, and mortality from, carcinomas of several sites and require confirmation in an independent trial of appropriate design before new public health recommendations regarding seenium supplementation can be made.
Abstract: Objective. —To determine whether a nutritional supplement of selenium will decrease the incidence of cancer. Design. —A multicenter, double-blind, randomized, placebo-controlled cancer prevention trial. Setting. —Seven dermatology clinics in the eastern United States. Patients. —A total of 1312 patients (mean age, 63 years; range, 18-80 years) with a history of basal cell or squamous cell carcinomas of the skin were randomized from 1983 through 1991. Patients were treated for a mean (SD) of 4.5 (2.8) years and had a total follow-up of 6.4 (2.0) years. Interventions. —Oral administration of 200 μg of selenium per day or placebo. Main Outcome Measures. —The primary end points for the trial were the incidences of basal and squamous cell carcinomas of the skin. The secondary end points, established in 1990, were all-cause mortality and total cancer mortality, total cancer incidence, and the incidences of lung, prostate, and colorectal cancers. Results. —After a total follow-up of 8271 person-years, selenium treatment did not significantly affect the incidence of basal cell or squamous cell skin cancer. There were 377 new cases of basal cell skin cancer among patients in the selenium group and 350 cases among the control group (relative risk [RR], 1.10; 95% confidence interval [CI], 0.95-1.28), and 218 new squamous cell skin cancers in the selenium group and 190 cases among the controls (RR, 1.14; 95% CI, 0.93-1.39). Analysis of secondary end points revealed that, compared with controls, patients treated with selenium had a nonsignificant reduction in all-cause mortality (108 deaths in the selenium group and 129 deaths in the control group [RR, 0.83; 95% CI, 0.63-1.08]) and significant reductions in total cancer mortality (29 deaths in the selenium treatment group and 57 deaths in controls [RR, 0.50; 95% CI, 0.31-0.80]), total cancer incidence (77 cancers in the selenium group and 119 in controls [RR, 0.63; 95% CI, 0.47-0.85]), and incidences of lung, colorectal, and prostate cancers. Primarily because of the apparent reductions in total cancer mortality and total cancer incidence in the selenium group, the blinded phase of the trial was stopped early. No cases of selenium toxicity occurred. Conclusions. —Selenium treatment did not protect against development of basal or squamous cell carcinomas of the skin. However, results from secondary end-point analyses support the hypothesis that supplemental selenium may reduce the incidence of, and mortality from, carcinomas of several sites. These effects of selenium require confirmation in an independent trial of appropriate design before new public health recommendations regarding selenium supplementation can be made.

2,780 citations

Journal ArticleDOI
TL;DR: Results from the Nutritional Prevention of Cancer Trial conducted among individuals at high risk of nonmelanoma skin cancer continue to demonstrate that selenium supplementation is ineffective at preventing basal cell carcinoma and that it increases the risk of squamous cell carcinomas and total nonmelanie skin cancer.
Abstract: The Nutritional Prevention of Cancer Trial was a double-blind, randomized, placebo-controlled clinical trial designed to test whether selenium as selenized yeast (200 microg daily) could prevent nonmelanoma skin cancer among 1312 patients from the Eastern United States who had previously had this disease. Results from September 15, 1983, through December 31, 1993, showed no association between treatment and the incidence of basal and squamous cell carcinomas of the skin. This report summarizes the entire blinded treatment period, which ended on January 31, 1996. The association between treatment and time to first nonmelanoma skin cancer diagnosis and between treatment and time to multiple skin tumors overall and within subgroups, defined by baseline characteristics, was evaluated. Although results through the entire blinded period continued to show that selenium supplementation was not statistically significantly associated with the risk of basal cell carcinoma (hazard ratio [HR] = 1.09, 95% confidence interval [CI] = 0.94 to 1.26), selenium supplementation was associated with statistically significantly elevated risk of squamous cell carcinoma (HR = 1.25, 95% CI = 1.03 to 1.51) and of total nonmelanoma skin cancer (HR = 1.17, 95% CI = 1.02 to 1.34). Results from the Nutritional Prevention of Cancer Trial conducted among individuals at high risk of nonmelanoma skin cancer continue to demonstrate that selenium supplementation is ineffective at preventing basal cell carcinoma and that it increases the risk of squamous cell carcinoma and total nonmelanoma skin cancer.

262 citations

Journal ArticleDOI
TL;DR: The need for long-term maintenance therapy with isotretinoin for chemoprevention of basal cell carcinoma may depend on the underlying cause of the skin cancers, particularly in patients with a history of arsenic exposure.
Abstract: Twelve patients with multiple basal cell carcinomas resulting from varying causes were treated with high-dose oral isotretinoin (mean daily dosage:3.1 mg/kg/day) for a mean of 8 months. Of the 270 tumors monitored in these patients, only 8% underwent complete clinical and histologic regression. All patients developed moderate to severe acute toxicities, leading five patients to withdraw from the study. Retinoid skeletal toxicity was identified in two patients who were examined after long-term therapy. Lower doses of isotretinoin (0.25 to 1.5 mg/kg/day) were ineffective for chemotherapy but demonstrated a chemopreventive effect in a subset of three patients who received these lower doses for 3 to 8 years. Two of these three patients have been observed after discontinuation of therapy. In one patient with a history of arsenic exposure, only one new tumor has appeared in a 27-month posttreatment observation period;in the other patient with the nevoid basal cell carcinoma syndrome, 29 new tumors have appeared within a 13-month period. This suggests that the need for long-term maintenance therapy with isotretinoin for chemoprevention of basal cell carcinoma may depend on the underlying cause of the skin cancers.

116 citations

Journal ArticleDOI
TL;DR: Five patients with basal cell carcinoma received fenretinide and two patients while receiving the drug had evidence of abnormal rod photoreceptor function that reversed rapidly on cessation of therapy, speculating that fen retinide may interfere with the binding of vitamin A to opsin or with the transport of Vitamin A.
Abstract: • Five patients with basal cell carcinoma received fenretinide. Two patients while receiving the drug had evidence of abnormal rod photoreceptor function that reversed rapidly on cessation of therapy. We speculate that fenretinide may interfere with the binding of vitamin A to opsin or with the transport of vitamin A.

101 citations

Journal ArticleDOI
TL;DR: Three patients with multiple basalcell carcinomas, due either to excessive sunlight exposure, the nevoid basal cell carcinoma syndrome, or arsenical insecticide exposure, were treated with oral isotretinoin for 2 1/2 to 4 years, and therapeutic effects varied between each patient.
Abstract: Three patients with multiple basal cell carcinomas, due either to excessive sunlight exposure, the nevoid basal cell carcinoma syndrome, or arsenical insecticide exposure, were treated with oral isotretinoin for 21/2 to 4 years. Although higher doses were used initially, approximately 1.5 mg/kg/day was used for long-term therapy in all three patients. Therapeutic effects on existing tumors varied between each patient, and only nine of sixty-five lesions underwent complete clinical regression. No tumors enlarged in two patients; a few tumors enlarged slightly in the third patient, particularly during the later courses of therapy when isotretinoin was given at lower dosage. No new lesions have been observed in any of these three patients. With these encouraging preliminary data, it now may be appropriate to perform larger trials for longer periods of time to determine the usefulness of isotretinoin in the chemoprevention of basal cell carcinoma in patients with multiple tumors.

83 citations


Cited by
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Journal ArticleDOI
TL;DR: This review examines the evidence for involvement of the oxidative stress in the carcinogenesis process and the role of enzymatic and non-enzymatic antioxidants in the process of carcinogenesis as well as the antioxidant interactions with various regulatory factors.

5,937 citations

Journal ArticleDOI
TL;DR: Selenium is needed for the proper functioning of the immune system, and appears to be a key nutrient in counteracting the development of virulence and inhibiting HIV progression to AIDS.

3,359 citations

01 Jan 2001
TL;DR: The essential trace mineral, selenium, is of fundamental importance to human health as mentioned in this paper, and it is needed for the proper functioning of the immune system, and appears to be a key nutrient in counteracting the development of virulence and inhibiting HIV progression to AIDS.
Abstract: The essential trace mineral, selenium, is of fundamental importance to human health. As a constituent of selenoproteins, selenium has structural and enzymic roles, in the latter context being best-known as an antioxidant and catalyst for the production of active thyroid hormone. Selenium is needed for the proper functioning of the immune system, and appears to be a key nutrient in counteracting the development of virulence and inhibiting HIV progression to AIDS. It is required for sperm motility and may reduce the risk of miscarriage. Deficiency has been linked to adverse mood states. Findings have been equivocal in linking selenium to cardiovascular disease risk although other conditions involving oxidative stress and inflammation have shown benefits of a higher selenium status. An elevated selenium intake may be associated with reduced cancer risk. Large clinical trials are now planned to confirm or refute this hypothesis. In the context of these health effects, low or diminishing selenium status in some parts of the world, notably in some European countries, is giving cause for concern.

3,068 citations

Journal ArticleDOI
TL;DR: The TrxR-catalyzed regeneration of several antioxidant compounds, including ascorbic acid (vitamin C), selenium-containing substances, lipoic acid, and ubiquinone are summarized.

2,632 citations

Journal ArticleDOI
TL;DR: The crucial factor that needs to be emphasised with regard to the health effects of selenium is the inextricable U-shaped link with status; whereas additional seenium intake may benefit people with low status, those with adequate-to-high status might be affected adversely and should not take selenum supplements.

2,297 citations