Gamel J W, Vogel R L, McLean I W
Veterans Administration Medical Center, Louisville, KY.
Br J Cancer. 1993 Jul;68(1):115-8. doi: 10.1038/bjc.1993.296.
The log-rank test is commonly used to assess therapeutic effect in prospective, randomised clinical trials. This test is sensitive to differences in survival between treatment groups at a specific endpoint, but cannot determine whether such a difference is due to an enhanced cure rate or an enhanced survival time among uncured patients. To investigate the clinical impact of such limitations, an algorithm was constructed to simulate clinical, randomised, adjuvant therapy trials in patients with a cured fraction of 0.27 and a median survival time for uncured patients of 3.4 years. Hypothetical therapies were introduced to increase rate of cure, increase median survival time, or achieve a combination of these effects. For 500 simulated patients recruited over a 5 year period and then followed for three additional years, a 50% enhancement of median survival time (to 5.1 years) led to a survival increase detectable at the P = 0.05 level in 780 of 1000 trials, whereas a 50% enhancement of cured fraction (to 40.5%) led to a detectable increase at the same level in only 449 of 1000 trials. These findings suggest that, in clinical trials of adjuvant therapy for stage 2 breast cancer, the log rank test may be more sensitive to increases in tumour-related survival time than to increases in cured fraction.
对数秩检验常用于评估前瞻性随机临床试验中的治疗效果。该检验对特定终点时治疗组之间的生存差异敏感，但无法确定这种差异是由于治愈率提高还是未治愈患者的生存时间延长所致。为了研究这些局限性的临床影响，构建了一种算法，以模拟治愈率为0.27且未治愈患者中位生存时间为3.4年的患者的临床随机辅助治疗试验。引入了假设疗法以提高治愈率、延长中位生存时间或实现这些效果的组合。对于在5年期间招募的500名模拟患者，然后再随访3年，中位生存时间提高50%（至5.1年）导致在1000次试验中的780次试验中，在P = 0.05水平可检测到生存增加，而治愈率提高50%（至40.5%）仅导致在1000次试验中的449次试验中在相同水平可检测到增加。这些发现表明，在2期乳腺癌辅助治疗的临床试验中，对数秩检验可能对肿瘤相关生存时间的增加比对治愈率的增加更敏感。
