Kwak Yoo-Kang, Kim Kyubo, Lee Jong Hoon, Kim Sung Hwan, Cho Hyeon Min, Kim Dae Yong, Kim Tae Hyun, Kim Sun Young, Baek Ji Yeon, Oh Jae Hwan, Nam Taek Keun, Yoon Mee Sun, Jeong Jae Uk, Chie Eui Kyu, Jang Hong Seok, Kim Jae Sung
Center for Colorectal Cancer, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea.
Department of Radiation Oncology, Seoul National University College of Medicine, Republic of Korea; Department of Radiation Oncology, Ewha Womans University School of Medicine, Republic of Korea.
Radiother Oncol. 2016 Jun;119(3):512-8. doi: 10.1016/j.radonc.2016.03.017. Epub 2016 Apr 19.
The definite surgical timing in rectal cancer after preoperative chemoradiotherapy (CRT) has not yet been fully examined. We assess the tumor response and identify the optimal operation timing after preoperative CRT in rectal cancer.
The study included data of 1786 patients with locally advanced rectal cancer (cT3-4N0-2M0). They received preoperative CRT followed by total mesorectal excision. Total radiation dose was 50.4Gy in 28 fractions. Interval time between preoperative CRT and surgery ranged from 2 to 26weeks, with a median interval of 7.2weeks. Primary endpoint was to evaluate the period of highest downstaging and pathological complete response (ypCR) rates to determine the optimal timing for curative surgery after CRT.
Downstaging rates peaked between 6 and 7weeks after CRT and declined afterward. ypCR rates increased from 5 to 6weeks after CRT and decreased after 9 to 10weeks. Downstaging rates were similar between the two arms showing 36.9% in the early arm (⩽7weeks) and 37.0% in the delayed arm (>7weeks). ypCR rates were significantly higher in the delayed arm, as compared to the early arm (12.3% vs. 8.6%, p=0.011). The delayed arm had higher sphincter preservation rates than the early arm with a marginal significance (92.4% vs. 89.9%, p=0.078). There was no statistically significant difference regarding relapse-free survival and overall survival between the two arms.
ypCR rates increased after 5weeks and decreased after 10weeks and the delayed (>7weeks after CRT) group showed significantly increased ypCR rates than the early arm (⩽7weeks after CR). The optimal timing for curative surgery in rectal cancer when tumor response is maximal is after 7weeks and before 10weeks following preoperative CRT.
术前放化疗（CRT）后直肠癌的确切手术时机尚未得到充分研究。我们评估肿瘤反应并确定直肠癌术前CRT后的最佳手术时机。
本研究纳入了1786例局部晚期直肠癌（cT3 - 4N0 - 2M0）患者的数据。他们接受了术前CRT，随后进行全直肠系膜切除术。总放疗剂量为50.4Gy，分28次给予。术前CRT与手术之间的间隔时间为2至26周，中位间隔时间为7.2周。主要终点是评估最高降期和病理完全缓解（ypCR）率的时期，以确定CRT后根治性手术的最佳时机。
降期率在CRT后6至7周达到峰值，之后下降。ypCR率在CRT后5至6周上升，9至10周后下降。两组的降期率相似，早期组（≤7周）为36.9%，延迟组（>7周）为37.0%。与早期组相比，延迟组的ypCR率显著更高（12.3%对8.6%，p = 0.011）。延迟组的括约肌保留率高于早期组，具有边缘显著性（92.4%对89.9%，p = 0.078）。两组之间的无复发生存率和总生存率无统计学显著差异。
ypCR率在5周后上升，10周后下降，延迟组（CRT后>7周）的ypCR率显著高于早期组（CRT后≤7周）。当肿瘤反应最大时，直肠癌根治性手术的最佳时机是在术前CRT后7周之后、10周之前。
