Sakuyama Naoki, Kojima Motohiro, Kawano Shingo, Akimoto Tetsuo, Saito Norio, Ito Masaaki, Ochiai Atsushi
Division of Colorectal Surgery, National Cancer Center Hospital East, Chiba, Japan.
Juntendo University Graduate School of Medicine, Advanced Clinical Research of Cancer, Tokyo, Japan.
Pathol Int. 2016 May;66(5):273-80. doi: 10.1111/pin.12409.
Pathological studies on the different histological effects between neoadjuvant chemotherapy (NAC) and preoperative chemoradiation therapy (preoperative CRT) have not been performed. The purpose of this study is to elucidate the histological differences in tissue received from NAC and preoperative CRT for rectal cancer to evaluate whether a pathological assessment method used after CRT can be applied for NAC. One hundred and thirty-eight patients were enrolled in this study; 88 patients underwent their operations after preoperative CRT or NAC, and 50 patients underwent surgery only. Residual tumor area was measured using morphometry software and we compared the stromal component of myofibroblasts, immune cells, and vasculature to elucidate the difference of therapeutic effect between them. The grade of reduction after preoperative CRT was more prominent than that seen in NAC. Also, ypT downstaging was more prominent in preoperative CRT than in NAC, and ypN downstaging was more frequent in NAC than in preoperative CRT. Preoperative CRT showed more marked myofibroblasts and fewer immune cells than did NAC, which indicates different effects on the cancer microenvironment. Our histological results suggest different effects between NAC and preoperative CRT on tumor tissue. The best assessment method available for a variable therapeutic protocol should be further investigated.
尚未对新辅助化疗（NAC）和术前放化疗（术前CRT）之间不同的组织学效应进行病理学研究。本研究的目的是阐明直肠癌患者接受NAC和术前CRT后组织的组织学差异，以评估CRT后使用的病理评估方法是否可应用于NAC。本研究共纳入138例患者；88例患者在术前CRT或NAC后接受手术，50例患者仅接受手术。使用形态测量软件测量残余肿瘤面积，并比较肌成纤维细胞、免疫细胞和脉管系统的基质成分，以阐明它们之间治疗效果的差异。术前CRT后的缩小程度比NAC更显著。此外，术前CRT的ypT降期比NAC更显著，而NAC的ypN降期比术前CRT更频繁。与NAC相比，术前CRT显示出更多的肌成纤维细胞和更少的免疫细胞，这表明对癌症微环境的影响不同。我们的组织学结果表明，NAC和术前CRT对肿瘤组织的影响不同。对于可变的治疗方案，应进一步研究可用的最佳评估方法。
