Search

Background: Results of a clinical trial recently completed in the United States indicate that administration of tamoxifen (20 mg/day) to women at risk can reduce breast cancer incidence by approximately 50% but is associated with an increased risk of developing endometrial cancer and venous thromboembolic events. Since these adverse effects may be dose related, we investigated the effect of tamoxifen on several biomarkers when the drug was given at doses lower than those currently in use.Methods: In two sequential experiments, 127 healthy hysterectomized women aged 35-70 years were randomly assigned to one of the following four treatment arms: placebo (n = 31) or tamoxifen at 20 mg/day (n = 30) (first experiment); or tamoxifen at 10 mg/day (n = 34) or tamoxifen at 10 mg/ alternate days (n = 32) (second experiment). Baseline and 2-month measurements of the following parameters were compared: 1) total cholesterol (primary end point) and other surrogate markers of cardiovascular disease, e.g., low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, and lipoprotein(a); 2) blood cell count; 3) fibrinogen; 4) antithrombin III; 5) osteocalcin; and, 6) in a subgroup of 103 women, insulin-like growth factor-I (IGF-I), a possible surrogate marker for breast cancer.Results: After adjustment for the baseline values, there were reductions in circulating levels of total cholesterol and IGF-I of the same magnitude in all three tamoxifen treatment arms. A similar pattern was observed for most of the other parameters. In the placebo arm, fibrinogen level, which showed a decrease, was the only parameter exhibiting change.Conclusions: Up to a 75% reduction in the conventional dose of tamoxifen (i.e., 20 mg/day) does not affect the activity of the drug on a large number of biomarkers, most of which are surrogate markers of cardiovascular disease. This study was hypothesis generating, and larger studies are warranted to assess the efficacy of tamoxifen at low doses. [ABSTRACT FROM AUTHOR]

Editorial. Investigates the efficacy of retinoids for ovarian cancer prevention in the United States. Assessment on retinoid activity; Recommendation of surrogate biomarkers for women undergoing ovarian surgery; Implementation of randomized clinical trials.

Background Initial findings of the Italian Randomized Tamoxifen Prevention Trial found no reduction in risk of breast cancer with tamoxifen use, whereas the National Surgical Adjuvant Breast and Bowel Project Breast Cancer Prevention Trial showed that tamoxifen treatment reduces risk of estrogen receptor-positive breast cancer. Here we present an extended follow-up of the Italian trial. Methods From October 1, 1992, to December 31, 1997, 5408 otherwise healthy women who had undergone hysterectomy were randomly assigned in a double-blind manner to tamoxifen (20 mg daily) or placebo for 5 years. Rates of breast cancer and other events in the two groups were compared by the use of risk ratios (RRs) and 95% confidence intervals (CIs). Results After 11 years of follow-up, 136 women (74 placebo, 62 tamoxifen) developed breast cancer (RR = 0.84, 95% CI = 0.60 to 1.17; annual rates were 2.48 and 2.07 per 1000 women-years, respectively). The rates of breast cancer in the two study groups were similar among women who had had bilateral oophorectomy and among women at low risk for hormone receptor-positive (HR+) disease but were much lower in the tamoxifen group among women at high risk (placebo, 6.26 per 1000 women-years, tamoxifen, 1.50 per 1000 women-years; RR = 0.24, 95% CI = 0.10 to 0.59). During the treatment period, women in the tamoxifen group reported more hot flashes (RR = 1.78, 95% CI = 1.57 to 2.00), vaginal discharge (RR = 3.44, 95% CI = 2.90 to 4.09), and urinary disturbances (RR = 1.52, 95% CI = 1.23 to 1.89) but fewer headaches (RR = 0.68, 95% CI = 0.50 to 0.94) than women in the placebo group. Hypertriglyceridemia (RR = 4.33, 95% CI = 1.96 to 9.53), thromboembolic events (RR = 1.63, 95% CI = 1.02 to 2.62), and cardiac arrhythmia or atrial fibrillation (RR = 1.73, 95% CI = 1.01 to 2.98) were also more frequent in the tamoxifen group than in the placebo group. Conclusions Appropriate selection of women at high risk for HR+ disease may improve the risk-benefit ratio of tamoxifen intervention. [ABSTRACT FROM AUTHOR]

Evaluates a randomized study of the impact of tamoxifen on Italian women with high-risks in hormone-dependent breast cancer. Criticism of research criteria design; Regulation of hormone responsiveness; Response from researchers.

Background: Tamoxifen reduces the risk of breast cancer in women at high risk for the disease but increases the risk for endometrial tumors and venous thromboembolisms, possibly in a dose-dependent fashion. We compared the effects of tamoxifen at 1 mg/day and 5 mg/day with those of the standard dose of 20 mg/day on breast cancer proliferation using a surrogate endpoint marker (Ki-67 expression) and blood biomarkers associated with breast cancer, cardiovascular disease, and bone fracture risk.Methods: We randomly assigned 120 women with estrogen receptor (ER)-positive breast cancer to tamoxifen at 1, 5, or 20 mg/day for 4 weeks. Expression of the tumor proliferation marker Ki-67 and of biomarkers of breast cancer (insulin-like growth factor-I, sex hormone-binding globulin), cardiovascular disease (cholesterol, triglycerides, ultrasensitive C-reactive protein, fibrinogen, antithrombin-III), and bone fracture (type I collagen C-telopeptide) risk were determined before (baseline) and after treatment. All levels were compared with those in two nonrandomized control groups (34 women with ER-negative breast cancer and 29 additional women with ER-positive breast cancer). Data were analyzed by analysis of covariance. All statistical tests were two-sided.Results: Expression of Ki-67 decreased in all three tamoxifen groups, with no difference in the magnitude of reduction among groups (P =.81). Relative to baseline, Ki-67 expression decreased by a median of 15.0% (95% confidence interval = 0.0% to 24.1%) among the tamoxifen groups but increased by 12.8% (95% confidence interval = 0.0% to 19.6%) among the nonrandomized control groups. Several blood biomarkers showed dose-response relationships with tamoxifen, including decreased insulin-like growth factor-I, increased sex hormone-binding globulin, and decreased low-density lipoprotein-cholesterol, ultrasensitive C-reactive protein, fibrinogen, and antithrombin-III levels.Conclusions: The effects on Ki-67 expression of lower doses of tamoxifen were comparable to those achieved with the standard dose, although the effects on blood biomarkers were variable. The effects of lower doses of tamoxifen should be assessed further in randomized trials. [ABSTRACT FROM AUTHOR]

Expression of retinoic acid receptor β (RARβ) and telomerase catalytic subunit (human telomerase reverse transcriptase [hTERT]) was analyzed in 285 bronchial biopsy specimens from 53 heavy cigarette smokers and four former smokers by using in situ hybridization. Of the 191 biopsy specimens that were positive for RARβ, 69% expressed hTERT, whereas only 54% of the 94 RARβ negative biopsy specimens expressed hTERT (P = .014). Because hTERT expression in bronchial tissue has been previously associated with increased risk of lung cancer, the association between RARβ and hTERT expression suggests that RARβ expression may be an indicator of increased risk of lung cancer in heavy smokers. [ABSTRACT FROM AUTHOR]

Background: Fenretinide, a vitamin A analogue, has been shown to inhibit breast carcinogenesis in preclinical studies. We determined the efficacy of fenretinide in preventing a second breast malignancy in women with breast cancer.Methods: We randomly assigned 2972 women, aged 30-70 years, with surgically removed stage I breast cancer or ductal carcinoma in situ to receive for 5 years either fenretinide orally (200 mg/day) or no treatment. The primary end point was the incidence of contralateral breast cancer or ipsilateral breast cancer 7 years after randomization. Other end points considered post hoc were the same outcomes stratified by menopausal status, incidence of distant metastases, overall mortality, and tumors in other organs. The hazards of breast cancer occurrence were determined by Cox proportional hazards regression analysis. Statistical tests were two-sided.Results: At a median observation time of 97 months, there were no statistically significant differences in the occurrence of contralateral breast cancer (P =.642) or ipsilateral breast cancer (P =.177) between the two arms. However, an interaction was detected between fenretinide treatment and menopausal status in both outcomes (P for interaction in both outcomes =.045), with a possible beneficial effect in premenopausal women (contralateral breast cancer: adjusted hazard ratio [HR] = 0.66, and 95% confidence interval [CI] = 0.41-1.07; ipsilateral breast cancer: adjusted HR = 0.65, and 95% CI = 0.46-0. 92) and an opposite effect in postmenopausal women (contralateral breast cancer: adjusted HR = 1.32, and 95% CI = 0.82-2.15; ipsilateral breast cancer: adjusted HR = 1.19, and 95% CI = 0.75-1. 89). There were no statistically significant differences between the two arms in tumors in other organs, incidence of distant metastasis, and all-cause mortality.Conclusions: Fenretinide treatment of women with breast cancer for 5 years appears to have no statistically significant effect on the incidence of second breast malignancies overall, although a possible benefit was detected in premenopausal women. These studies, particularly the post hoc analyses, are considered exploratory and need to be confirmed. [ABSTRACT FROM AUTHOR]

Studies the effect of the synthetic retinoid fenretinide on dark adaptation and the ocular surface. Therapeutic effects of fenretinide; Measurement of dark adaptation changes and comparing the measured results with the patient's subjective perception; Definition of the association with plasma retinol levels; Assessment of the reversibility of alterations.

The article introduces the two placebo-controlled clinical trials of tamoxifen for the prevention of breast cancer that are published within the issue.

Presents the results of a Phase IIa study of the synthetic retinoid fenretinide in superficial bladder cancer using DNA flow cytometry as an intermediate end point. Reports on the effectiveness of retinoids as inhibitors of bladder carcinogenesis in rodents; Toxicity effects.

Responses by Umberto Veronesi, Bernardo Bonanni, and Andrea Decensi to a letter to the editor about an article on the late results of the Italian Tamoxifen Prevention Trial in the previous issue are presented.