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Background: Most recurrences in women with breast cancer receiving 5 years of adjuvant tamoxifen occur after 5 years. The MA.17 trial, which was designed to determine whether extended adjuvant therapy with the aromatase inhibitor letrozole after tamoxifen reduces the risk of such late recurrences, was stopped early after an interim analysis showed that letrozole improved disease-free survival. This report presents updated findings from the trial. Methods: Postmenopausal women completing 5 years of tamoxifen treatment were randomly assigned to a planned 5 years of letrozole (n = 2593) or placebo (n = 2594). The primary endpoint was disease-free survival (DFS); secondary endpoints included distant disease-free survival, overall survival, incidence of contralateral tumors, and toxic effects. Survival was examined using Kaplan-Meier analysis and log-rank tests. Planned subgroup analyses included those by axillary lymph node status. All statistical tests were two-sided. Results: After a median follow-up of 30 months (range = 1.5-61.4 months), women in the letrozole arm had statistically significantly better DFS and distant DFS than women in the placebo arm (DFS: hazard ratio [HR] for recurrence or contralateral breast cancer = 0.58, 95% confidence interval [CI] = 0.45 to 0.76; P

Background: The toxicity of a given cancer therapy is an important end point in clinical trials examining the potential costs and benefits of that therapy. Treatment-related toxicity is conventionally measured with one of several toxicity criteria grading scales, even though the reliability and validity of these scales have not been established. Purpose: We determined the reliability of the National Cancer Institute of Canada Clinical Trials Group (NCIC-CTG) expanded toxicity scale and the World Health Organization (WHO) standard toxicity scale by use of a clinical simulation of actual patients. Methods: Seven experienced data managers each interviewed 12 simulated patients and scored their respective acute toxic effects. Inter-rater agreement (agreement between multiple raters of the same case) was calculated using the kappa (K) statistic across all seven randomly assigned raters for each of 18 toxicity categories (13 NCIC-CTG and five WHO categories). Intra-rater agreement (agreement within the same rater on one case rated on separate occasions) was calculated using K over repeated cases (where raters were blinded to the repeated nature of the subjects). Proportions of agreement (estimate of the probability of two randomly selected raters assigning the same toxicity grade to a given case) were also calculated for inter-rater agreement. Since minor lack of agreement might have adversely affected these statistics of agreement, both K and proportion of agreement analyses were repeated for the following condensed grading categories: none (0) versus low-grade (1 or 2) versus high-grade (3 or 4) toxicity present. Results: Modest levels of inter-rater reliability were demonstrated in this study with K values that ranged from 0.50 to 1.00 in laboratory-based categories and from -0.04 to 0.82 for clinically based categories. Proportions of agreement for clinical categories ranged from 0.52 to 0.98. Condensing the toxicity grades improved statistics of agreement, but substantial lack of agreement remained (K range, -0.04-0.82; proportions of agreement range, 0.67-0.98). Conclusions: Experienced data managers, when interviewing patients, draw varying conclusions regarding toxic effects experienced by such patients. Neither the NCIC-CTG expanded toxicity scale nor the WHO standard toxicity scale demonstrated a clear superiority in reliability, although the breadth of toxic effects recorded differed. [J Natl Cancer Inst 85:1138-1148, 1993]

* Background. - Recommendations are broadening for the prophylaxis of atherosclerotic disorders, but aspirin is the only widely used agent. Ticlopidine hydrochloride, a new antiplatelet medication, has recently been approved for prescription in North America. We reviewed the major clinical trials of ticlopidine and derived guidelines for its use. Methods. - Studies of ticlopidine were sought through MEDLINE for 1980 to 1990 and through bibliographies of retrieved articles. All published, randomized trials of ticlopidine were appraised if they reported major morbidity and mortality as primary end points. All eligible studies were formally reviewed by an expert panel according to published principles for critical appraisal of the medical literature. Both benefits and risks were quantified. Results. - Four randomized trials reported major clinical end points. In these, ticlopidine was more effective than placebo for preventing recurrences after completed stroke; was more effective than aspirin for patients with transient ischemic attacks and partial strokes; and reduced vascular death and nonfatal myocardial infarction in an open trial among patients with unstable angina. For patients with intermittent claudication ticlopidine, was not significantly better than placebo for preventing myocardial infarction or stroke. Side effects were more common with ticlopidine than with aspirin or placebo. Conclusions. - Ticlopidine should be prescribed in place of aspirin for stroke prophylaxis or unstable angina if the patient is unable to tolerate aspirin. Ticlopidine may also benefit patients who experience new ischemic events while taking aspirin or, probably, patients with peripheral vascular disease. A complete blood cell count should be performed every 2 weeks during the first 3 months of therapy to check for leukopenia. (Arch Intern Med. 1992; 152:1376-1380)