See W A, Cohen M B, Hoxie L D
Department of Urology, University of Iowa Hospitals and Clinics, Iowa City 52242-1089.
Cancer. 1993 Mar 15;71(6):2048-54. doi: 10.1002/1097-0142(19930315)71:6<2048::aid-cncr2820710620>3.0.co;2-r.
Alpha-fetoprotein (AFP) serum values after orchiectomy for testicular cancer can be used to predict the residual disease status. However, the optimal strategy for postorchiectomy marker analysis has not been studied. This article evaluated different analytic methods in an effort to identify the approach that provided the greatest sensitivity and specificity for occult residual disease.
Statistical information on the AFP half-life (t1/2) derived from a clinical data set of 24 patients with AFP-secreting clinical Stage A testicular cancer and pathologically defined nodal status was incorporated into a mathematic model of postorchiectomy marker values as a function of residual tumor volume and time. The model was used to test the effect of various analytic strategies on detecting the residual tumor. The clinical data set then was analyzed to measure the effect of different analytic methods on the predictive value of the AFP t1/2.
In the model, the AFP t1/2 calculated from a single set of serum measurements obtained from the initial serum t1/2 was a poor predictor of disease status in patients with up to 40% residual tumor volume. Determined by the sequential addition of serum values obtained at normal t1/2 intervals, the AFP t1/2 improved in sensitivity but required up to seven serial values (35 days) to detect an abnormal t1/2 in patients with 10% residual tumor. By contrast, changes in the most recent interval t1/2 relative to the initial calculated t1/2 predicted the disease status in patients with 10% residual tumor after four t1/2 (20 days) and in patients with 1% residual volume after 35 days.
The use of this last strategy in the clinical data set improved both the sensitivity and specificity of the AFP t1/2 in predicting residual tumor relative to the other methods.
睾丸癌睾丸切除术后的甲胎蛋白（AFP）血清值可用于预测残留疾病状态。然而，睾丸切除术后标志物分析的最佳策略尚未得到研究。本文评估了不同的分析方法，以确定对隐匿性残留疾病具有最高敏感性和特异性的方法。
从24例分泌AFP的临床A期睾丸癌患者的临床数据集以及病理确定的淋巴结状态中得出的AFP半衰期（t1/2）的统计信息，被纳入一个睾丸切除术后标志物值的数学模型，该模型是残留肿瘤体积和时间的函数。该模型用于测试各种分析策略对检测残留肿瘤的效果。然后对临床数据集进行分析，以测量不同分析方法对AFP t1/2预测价值的影响。
在模型中，从初始血清t1/2获得的单组血清测量值计算出的AFP t1/2，对于残留肿瘤体积高达40%的患者，是疾病状态的较差预测指标。通过以正常t1/2间隔顺序添加血清值来确定，AFP t1/2的敏感性有所提高，但对于残留肿瘤为10%的患者，需要多达7个连续值（35天）才能检测到异常的t1/2。相比之下，相对于初始计算的t1/2，最近间隔t1/2的变化在4个t1/2（20天）后可预测残留肿瘤为10%的患者的疾病状态，在35天后可预测残留体积为1%的患者的疾病状态。
相对于其他方法，在临床数据集中使用最后一种策略可提高AFP t1/2预测残留肿瘤的敏感性和特异性。
