Dunn B K, Kramer B S, Ford L G
Division of Cancer Prevention, National Cancer Institute, Rockville, Maryland, USA.
Hematol Oncol Clin North Am. 1998 Oct;12(5):1019-36, vii. doi: 10.1016/s0889-8588(05)70039-3.
Clinical trials to evaluate interventions for cancer prevention are designed as early (phase I, IIa, and IIb) or late-phase studies. Whereas the former are small and generally rely on intermediate endpoint biomarkers of carcinogenesis, the latter are large-scale, long-term, randomized, phase III studies that address endpoints such as cancer incidence. The Breast Cancer Prevention Trial, P-1, conducted by the National Surgical Adjuvant Breast and Bowel Project (NSABP), is discussed as an example of a large, extended, phase III trial designed to answer the question of whether tamoxifen reduces the incidence of breast cancer in women who are at increased risk for the disease.
评估癌症预防干预措施的临床试验被设计为早期（I期、IIa期和IIb期）或晚期研究。前者规模较小，通常依赖致癌作用的中间终点生物标志物，而后者是大规模、长期、随机的III期研究，涉及癌症发病率等终点。由国家外科辅助乳腺和肠道项目（NSABP）开展的乳腺癌预防试验（P-1），作为一项大型、长期的III期试验的例子进行讨论，该试验旨在回答他莫昔芬是否能降低患乳腺癌风险增加的女性乳腺癌发病率这一问题。
