Cho Min Soo, Kim HonSoul, Han Yoon Dae, Hur Hyuk, Min Byung Soh, Baik Seung Hyuk, Cheon Jae Hee, Lim Joon Seok, Lee Kang Young, Kim Nam Kyu
Division of Colon and Rectal Surgery, Yonsei University College of Medicine.
Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine.
Medicine (Baltimore). 2019 Aug;98(35):e16614. doi: 10.1097/MD.0000000000016614.
Accurate tumor response determination remains inconclusive after preoperative chemoradiation therapy (CRT) for rectal cancer. This study aimed to investigate whether clinical assessment, such as endoscopy and magnetic resonance imaging (MRI), can accurately predict ypT stage and select candidates for pelvic organ-preserving surgery in rectal cancer after preoperative CRT. A total of 110 patients who underwent preoperative CRT followed by curative resection for rectal cancer were prospectively enrolled. Magnetic resonance tumor regression grade (mrTRG) using T2-MRI, endoscopic evaluation, and combination modality (combination of endoscopy and mrTRG) were used to analyze tumor response after preoperative CRT. Endoscopic findings were categorized as 3 grades and the mrTRG was assessed into 5 grades. Twenty-nine patients (26.4%) had achieved pathologic complete response. When predicting ypT0, endoscopy showed significantly higher area under the curve (AUC 0.818) than did mrTRG (AUC 0.568) and combination modality (AUC 0.768) in differentiating good response from poor response (P < .001). Both endoscopy and combination modality showed significantly higher diagnostic performance in sensitivity (79.31%), positive predictive value (PPV 67.65%), negative predictive value (NPV 92.11%), and accuracy (84.55%) than those of MR tumor response (sensitivity 37.93%, PPV 36.67%, NPV 77.50%, and accuracy 66.36%) for the prediction of ypT0 (P < .001). Combination modality showed significantly higher diagnostic performance in sensitivity (56.92%), NPV (56.92%), and accuracy (67.27%) compared with those of mrTRG. Neither endoscopy, nor mrTRG, nor the combination modality had adequate diagnostic performances to be clinically acceptable in selecting candidates for nonoperative treatment strategies. However, endoscopy may be incorporated in clinical restaging strategy in planning the extent of surgical resection in patients with rectal cancer.
对于直肠癌患者，术前放化疗（CRT）后准确判定肿瘤反应仍无定论。本研究旨在探讨诸如内镜检查和磁共振成像（MRI）等临床评估能否准确预测ypT分期，并为术前CRT后的直肠癌患者选择保留盆腔器官手术的候选者。前瞻性纳入了110例行术前CRT并随后接受直肠癌根治性切除术的患者。利用T2-MRI的磁共振肿瘤退缩分级（mrTRG）、内镜评估以及联合模式（内镜检查与mrTRG相结合）分析术前CRT后的肿瘤反应。内镜检查结果分为3级，mrTRG评估为5级。29例患者（26.4%）达到病理完全缓解。在区分反应良好与反应不佳时，预测ypT0时，内镜检查的曲线下面积（AUC 0.818）显著高于mrTRG（AUC 0.568）和联合模式（AUC 0.768）（P<0.001）。在预测ypT0方面，内镜检查和联合模式在敏感性（79.31%）、阳性预测值（PPV 67.65%）、阴性预测值（NPV 92.11%）和准确性（84.55%）方面均显示出显著高于MR肿瘤反应的诊断性能（敏感性37.93%、PPV 36.67%、NPV 77.50%、准确性66.36%）（P<0.001）。联合模式在敏感性（56.92%）、NPV（56.92%）和准确性（67.27%）方面显示出显著高于mrTRG的诊断性能。内镜检查、mrTRG或联合模式在选择非手术治疗策略的候选者方面均没有足够的诊断性能以被临床接受。然而，在规划直肠癌患者的手术切除范围时，内镜检查可纳入临床再分期策略。
