Liu Charles, Boncompagni Ana Carolina A, Perrone Kenneth H, Agarwal Ank A, Hur Dong G, Lopez Ivan, Sheth Vipul, Morris Arden M
Section of Colorectal Surgery, Division of General Surgery, University of Washington School of Medicine, Seattle, Washington.
Department of Surgery, Stanford University School of Medicine, Stanford, California.
J Surg Res. 2025 Feb;306:474-478. doi: 10.1016/j.jss.2024.12.042. Epub 2025 Jan 27.
Previous research has demonstrated that after neoadjuvant therapy for rectal cancer, the sensitivity of magnetic resonance complete response (mrCR) for detecting pathologic complete response (pCR) in the surgical specimen ranges from 74 to 94%. Patient and provider interest in nonoperative management of rectal cancer that responds favorably to neoadjuvant therapy has grown, necessitating stronger evidence for how well radiographic complete response truly predicts pCR. We sought to determine the current association between mrCR and pCR in locally advanced rectal cancer.
We conducted a retrospective cohort study of patients with rectal adenocarcinoma who underwent neoadjuvant chemoradiation followed by index proctectomy at a single academic referral center from January 2012 to December 2021. Our primary outcomes were mrCR, defined as the absence of residual disease on restaging MRI, and pCR, defined as the absence of residual adenocarcinoma in surgical pathology specimens.
Among 523 eligible patients, 157 met the inclusion criteria (38.9% females; 51.0% nonwhite; mean [SD] age, 58.6 [13.2] years). Overall, 8.9% of patients had mrCR and 7.0% had pCR. The sensitivity and positive predictive value of mrCR were 36.4% (95% CI: 10.9 to 69.2) and 28.6% (95% CI: 8.4 to 58.1). Our findings were qualitatively unchanged when only patients in the last 5 years of the study period were included. Study limitations include that neoadjuvant therapy regimens were not standardized and patients who were offered and elected to undergo nonoperative management were not included.
The value of mrCR in predicting pathologic response following neoadjuvant therapy in locally advanced rectal cancer is low, and mrCR should be interpreted with caution when counseling patients about nonoperative management. Early, frequent surveillance is critical in patients who elect nonoperative management after mrCR.
既往研究表明，直肠癌新辅助治疗后，磁共振成像完全缓解（mrCR）用于检测手术标本中病理完全缓解（pCR）的敏感性为74%至94%。患者和医疗服务提供者对新辅助治疗反应良好的直肠癌非手术治疗的兴趣日益增加，因此需要更有力的证据来证明影像学完全缓解对pCR的预测准确性。我们试图确定局部晚期直肠癌中mrCR与pCR之间的当前关联。
我们对2012年1月至2021年12月在单一学术转诊中心接受新辅助放化疗并随后进行根治性直肠切除术的直肠腺癌患者进行了一项回顾性队列研究。我们的主要结局指标是mrCR（定义为再次分期MRI上无残留病灶）和pCR（定义为手术病理标本中无残留腺癌）。
在523例符合条件的患者中，157例符合纳入标准（女性占38.9%；非白人占51.0%；平均[标准差]年龄为58.6[13.2]岁）。总体而言，8.9%的患者有mrCR，7.0%的患者有pCR。mrCR的敏感性和阳性预测值分别为36.4%（95%CI：10.9至69.2）和28.6%（95%CI：8.4至58.1）。仅纳入研究期间最后5年的患者时，我们的研究结果在定性上没有变化。研究局限性包括新辅助治疗方案未标准化，且未纳入接受并选择非手术治疗的患者。
mrCR在预测局部晚期直肠癌新辅助治疗后的病理反应方面价值较低，在为患者提供非手术治疗咨询时应谨慎解释mrCR结果。对于mrCR后选择非手术治疗的患者，早期、频繁的监测至关重要。
