Abstract

Background

Carcinoembryonic antigen (CEA) levels are used in conjunction with imaging to monitor response to systemic therapy in metastatic colorectal cancer (mCRC). We sought to identify a threshold for CEA change from baseline to predict progressive disease (PD) in mCRC patients receiving first-line therapy.

Methods

Patients from trials collected in the ARCAD database were included if baseline CEA was at least 10 ng/mL and repeat CEA was available within 14 days of first restaging scan. Optimal cutoffs for CEA change were identified by receiver operating characteristic analysis. Prediction performance of cutoffs was evaluated by sensitivity, specificity, and negative predictive value. Analyses were conducted by treatment class: chemotherapy alone, chemotherapy with anti-VEGF antibody, and chemotherapy with anti-EGFR antibody.

Results

A total of 2643 mCRC patients treated with systemic therapy were included. Median percent change of CEA from baseline to first restaging for patients with complete response, partial response, or stable disease (non-PD) and PD was −53.1% and +23.6% for chemotherapy alone (n = 957) and −71.7% and −45.3% for chemotherapy with anti-VEGF antibody (n = 1355). The optimal area under the curve cutoff for differentiating PD from non-PD on first restaging was −7.5% for chemotherapy alone and −62.0% for chemotherapy with anti-VEGF antibody; chemotherapy alone, adjusted odds ratio = 6.51 (95% CI = 3.31 to 12.83, P < .001), chemotherapy with anti-VEGF antibody, adjusted odds ratio = 3.45 (95% CI = 1.93 to 6.18, P < .001). A 99% negative predictive value clinical cutoff for prediction of non-PD would avoid CT scan at first restaging in 21.0% of chemotherapy alone and 16.2% of chemotherapy with anti-VEGF antibody–treated patients. Among patients with stable disease on first restaging, those with decreased CEA from baseline had statistically significantly improved progression-free and overall survival.

Conclusions

Change in CEA from baseline to first restaging can accurately predict non-progression and correlates with long-term outcomes in patients receiving systemic chemotherapy.

中文翻译：

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CEA阈值变化可作为转移性结直肠癌患者CEA升高的一线系统治疗未进展的预测指标

摘要

背景

癌胚抗原（CEA）水平与影像学结合使用，以监测对转移性结直肠癌（mCRC）全身治疗的反应。我们试图确定接受一线治疗的mCRC患者的CEA从基线变化到预测疾病进展（PD）的阈值。

方法

如果基线CEA至少为10 ng / mL，并且在首次再分期扫描后的14天内可以重复使用CEA，则将来自ARCAD数据库中收集的试验的患者包括在内。通过接收器工作特性分析确定了CEA变化的最佳截止点。通过敏感性，特异性和阴性预测值评估了临界值的预测性能。按治疗类别进行分析：单独化疗，抗VEGF抗体化疗和抗EGFR抗体化疗。

结果

总共纳入了2643名接受全身治疗的mCRC患者。对于完全缓解，部分缓解或疾病稳定（非PD）和PD的患者，CEA从基线到首次重诊的CEA改变的中位数百分比为单独化疗（n  =  957）为-53.1％和+ 23.6％，n = 957，为-71.7％。使用抗VEGF抗体进行化疗时为-45.3％（n  =  1355）。初次分期时将PD与非PD区分开的最佳曲线下截面积，单用化疗为-7.5％，抗VEGF抗体化疗为-62.0％。单独化疗，调整后的优势比= 6.51（95％CI = 3.31至12.83，P  <.001），用抗VEGF抗体化疗，调整后的优势比= 3.45（95％CI = 1.93至6.18，P <.001）。对于非PD预测，使用99％的阴性预测值临床临界值可以避免在重新分期进行CT扫描时，仅21.0％的化疗药物和16.2％的抗VEGF抗体治疗的患者可以避免再次扫描。在初次分期时病情稳定的患者中，CEA从基线下降的患者在统计学上显着改善了无进展生存期和总生存期。

结论

从基线到初次分期，CEA的变化可以准确预测不进展，并与接受全身化疗的患者的长期预后相关。