Trends in Prostate and Breast Cancer Clinical Research as Reported in the American Society of Clinical Oncology Proceedings

Objectives: To identify recent clinical research trends, all abstracts relevant to prostate and breast cancer reported in the American Society of Clinical Oncology (ASCO) Proceedings from 1994 to 1999 and for 1 year in the American Urological Association Proceedings were reviewed. Methods: Abstracts were identified and prospectively categorized in 31 areas including study design, sample size, and study outcome. Results: In the ASCO Proceedings, abstracts on breast cancer (n = 1718) greatly exceeded those on prostate cancer (n = 340). Randomized clinical trials were also more frequently reported in breast cancer compared to prostate cancer (176 versus 30 reports, respectively [5.7 times greater]; p 12 times as many patients (121,923 women versus 9,761 men, respectively; p < 0.01) in this period. For breast cancer, the number of reported randomized clinical trials increased and nearly doubled over the 6-year period, whereas for prostate cancer no such trend was seen. For prostate cancer, the vast majority (82%) of the 130 clinical trial reports were nonrandomized studies, and most entered very few patients (median patient entry, 26.2). Although randomized clinical trial reports on breast cancer described significant survival benefits in 16 trials in both advanced disease (benefit seen in 7 of 109 studies [6%]) and especially in adjuvant therapy (benefit seen in 9 of 67 studies [12%]), in prostate cancer only a single randomized clinical trial reported a significant survival benefit in this period. Conclusions: Despite comparable annual incidence and mortality, prostate cancer receives only a fraction of the clinical trial activity afforded breast cancer.