Spermon Jesse Roan, Hoffmann Aswin L, Horenblas Simon, Verbeek Andre L M, Witjes J Alfred, Kiemeney Lambertus A
Department of Urology, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
Eur Urol. 2005 Aug;48(2):258-67; discussion 267-8. doi: 10.1016/j.eururo.2005.04.021.
There is no universally accepted standard protocol for surveillance of patients with clinical stage I Non Seminomatous Germ Cell Tumors (CS I NSGCT). Prospective studies to compare different follow-up policies have not been performed, even though a great deal of time and resources is spent in surveillance. In this study, we constructed a Markov model to evaluate the impact of different follow-up strategies on disease-specific mortality (DSM) and life expectancy (LE) of patients with CS I NSGCT.
A discrete time non-homogeneous semi-Markov model was used to simulate different follow-up strategies for a hypothetical population of CS I NSGCT patients. Estimates of the model parameters were based on the literature. Output parameters were DSM and LE. Three different strategies were compared: (1) the intensive The Netherlands Cancer Institute/Antoni van Leeuwenhoek hospital (NCI/AvL) protocol; (2) the European Association of Urology (EAU) protocol; and (3) a hypothetical minimal protocol (i.e. follow-up limited to the first two years). Furthermore, we evaluated the impact of abdominal CT scans and chest X-rays on DSM.
Comparing with the EAU protocol (DSM: 3.05%; LE: 53.3 years), the intensive NCI/AvL protocol leads to a 1.2% lower DSM and a 6 months higher LE (DSM: 1.81%; LE: 53.9 years). The hypothetical follow-up scenario during the first two years shows a DSM of 6.83% and an LE of 51.4 years. Abdominal CT scans of the retroperitoneal lymph nodes appear to be important, while chest X-rays have little impact on DSM.
A follow-up policy limited to the first two years will result in an unacceptable high percentage of death from disease (6.83%). The relatively small benefit of an intensive follow-up protocol as proposed by the NCI/AvL, compared to that of the EAU, must be weighed against its economic and psychological costs. Our model suggests that CT-scanning is essential for a low DSM, whereas the large number of X-rays seem to have little additional effect.
对于临床I期非精原细胞性生殖细胞肿瘤（CS I NSGCT）患者的监测，尚无普遍接受的标准方案。尽管在监测方面投入了大量时间和资源，但尚未开展前瞻性研究来比较不同的随访策略。在本研究中，我们构建了一个马尔可夫模型，以评估不同随访策略对CS I NSGCT患者疾病特异性死亡率（DSM）和预期寿命（LE）的影响。
使用离散时间非齐次半马尔可夫模型来模拟CS I NSGCT患者假设群体的不同随访策略。模型参数的估计基于文献。输出参数为DSM和LE。比较了三种不同策略：（1）荷兰癌症研究所/安东尼·范·列文虎克医院（NCI/AvL）的强化方案；（2）欧洲泌尿外科学会（EAU）方案；（3）一种假设的最小方案（即随访仅限于前两年）。此外，我们评估了腹部CT扫描和胸部X光对DSM的影响。
与EAU方案（DSM：3.05%；LE：53.3年）相比，NCI/AvL强化方案导致DSM降低1.2%，LE延长6个月（DSM：1.81%；LE：53.9年）。前两年的假设随访方案显示DSM为6.83%，LE为51.4年。腹膜后淋巴结的腹部CT扫描似乎很重要，而胸部X光对DSM影响很小。
仅限于前两年的随访策略将导致不可接受的高疾病死亡率（6.83%）。与EAU方案相比，NCI/AvL提出的强化随访方案的相对较小益处，必须与其经济和心理成本相权衡。我们的模型表明，CT扫描对于降低DSM至关重要，而大量的X光似乎几乎没有额外效果。
