Neuman Heather B, Elkin Elena B, Guillem Jose G, Paty Philip B, Weiser Martin R, Wong W Douglas, Temple Larissa K
Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA.
Dis Colon Rectum. 2009 May;52(5):863-71. doi: 10.1007/DCR.0b013e31819eefba.
A clinical complete response to neoadjuvant therapy occurs in a subset of patients with rectal cancer. Management of these patients is controversial and tension exists between the recurrence risk with observation, and the impact of surgery on quality-of-life. Therefore, the objective was to develop a decision-analytic model to evaluate the relative benefits of surgery vs. observation in rectal cancer patients who achieve clinical complete response after neoadjuvant chemoradiation.
Clinically relevant inputs and events, including the ability to identify complete responders, likelihood of relapse and of salvage surgery after relapse, and utilities for each health state, were simulated by use of a Markov state-transition model. Transition probabilities and health-state utilities were derived from the literature and expert consensus. One-way and two-way sensitivity analyses were performed to assess the robustness of model results to assumptions. The primary outcome was quality-adjusted life expectancy.
In the base-case analysis, the quality-adjusted life expectancy with surgery exceeded observation (5.63 vs. 5.34 quality-adjusted life-years). Sensitivity analysis demonstrated that observation was preferred to surgery if the ability to correctly identify patients with true complete responses exceeded 58 percent, if quality-of-life after surgery was poor (utility <0.81), or if the relative reduction in recurrence risk with surgery was <43 percent when compared with observation.
Our model outlines the issues associated with surgery vs. observation, and suggests that surgery is beneficial for the average patient with rectal cancer with a clinical complete response after neoadjuvant therapy. Current limitations in the clinical assessment of patient response to chemoradiation constitute an important factor influencing our results, and therefore warrant further investigation.
部分直肠癌患者对新辅助治疗可出现临床完全缓解。这些患者的管理存在争议，在观察带来的复发风险与手术对生活质量的影响之间存在矛盾。因此，本研究旨在建立一个决策分析模型，以评估在新辅助放化疗后达到临床完全缓解的直肠癌患者中，手术与观察相比的相对获益。
利用马尔可夫状态转移模型模拟临床相关的输入和事件，包括识别完全缓解者的能力、复发可能性以及复发后挽救性手术的可能性，以及每种健康状态的效用值。转移概率和健康状态效用值来自文献和专家共识。进行单向和双向敏感性分析，以评估模型结果对假设的稳健性。主要结局为质量调整生命预期。
在基础病例分析中，手术组的质量调整生命预期超过观察组（5.63个质量调整生命年对5.34个质量调整生命年）。敏感性分析表明，如果正确识别真正完全缓解患者的能力超过58%，如果手术后生活质量较差（效用值<0.81），或者与观察相比手术使复发风险的相对降低<43%，则观察优于手术。
我们的模型概述了手术与观察相关的问题，并表明手术对新辅助治疗后出现临床完全缓解的直肠癌普通患者有益。目前患者对放化疗反应的临床评估局限性是影响我们结果的一个重要因素，因此值得进一步研究。
