局部进展期直肠癌术前新辅助治疗后凋亡相关蛋白检测及临床意义

Detection and clinical significance of apoptosis related protein in local advanced rectal cancer patients with preoperative neoadjuvant therapy

目的通过局部进展期直肠癌患者术前同步放化疗前、后的凋亡相关蛋白的检测，探讨放化疗诱导直肠癌凋亡的机制并评价其疗效。方法应用免疫组化EnVision法检测术前同步放化疗前、后Bcl—XL、Bax表达，结合患者临床、病理各项指标，进行统计学分析和评价。结果术前同步放化疗后肿瘤细胞退缩明显（TRG2＋TRG3＋TRG4）患者13例，无退缩（TRGO＋TRGl）患者21例，术前同步放化疗前、后Bcl—XL阳性率分别为58．8％（20／34）和52．9％（18／34），放化疗前、后Bcl-XL表达变化与放化疗前肿瘤大小，放疔后肿瘤细胞退缩以及手术方式之间差异有统计学意义。术前同步放化疗前、后Bax阳性率分别为32．4％（11／34）和44．1％（15／34），Bax表达变化与放疗后肿瘤细胞退缩间差异无统计学意义。术前同步放化疗前、后Bcl—XL／Bax比值之间差异有统计学意义（χ^2=9．607，P=0．048）。术前同步放化疗前、后Bcl—XL/MBax比值与肿瘤细胞退缩之间差异无统计学意义。按照术前同步放化疗是否加热疗进行分层分析，发现单纯放化疗组Bcl—XL表达变化与手术方式之间差异有统计学意义（χ^2=13．964，P=0．007），单纯放化疗组Bax表达变化与肿瘤肌层浸润和放疗后肿瘤细胞退缩之间差异有显著性意义（χ^2=10．806、10．455，P〈0．05）。结论术前同步放化疗可以改变Bcl—XL、Bax表达，影响直肠癌细胞凋亡和患者治疗效果，Bcl—XL表达减低和Bax表达上调在术前同步放化疗诱导直肠癌细胞凋亡中具有重要的临床作用，可有效提高直肠癌放化疗的效果。

Objective To discuss the mechanism of rectal cancer apoptosis induced by preoperative chemoradiotherapy and evaluate its effect by detection of apoptosis related proteins in locally advanced colorectal cancer patients who had received preoperative chemoradiation. Methods To detect Bcl-XL and Bax expression in rectal cancer before and after chemoradiotherapy by EnVision method, combined with patients clinical and pathological index, statistically analysis and evaluation their relationship and clinical significance. Results Patients with or without tumor shrinkage after preoperative cbemoradiotherapy was 13 cases and 21 cases. While the positive rate of Bcl-XL in rectal cancer before and after chemoradiotherapy were 58.8% （ 20/34 ） and 52. 9% （ 18/34 ） , respectively. There were significant difference between Bcl-XL change before and after chemoradiation with tumor size, tumor cells shrinkage and operation pattern. The positive rate of Bax in rectal cancer before and after chemoradiotherapy were 32.4% （11/34） and 44. 1% （15/34） , respectively. There were no significant difference between Bax change before and after chemoradiotherapy with tumor cells shrinkage. There were statistically significant difference between Bax ratio （χ^2 = 9. 607, P = 0. 048 ） before and after chemoradiation while there were no significant difference between Bcl-XL/Bax ratio before and after chemoradiation with tumor shrinkage. According to layeredanalysis with preoperative therapy, there were statistically significant difference （χ^2 ~ 13. 964, P = 0. 007 ） between Bcl-XL change with operation pattern while the same of significant differenee between Bax ehange with tumor infihration and tumor shrinkage （ χ^2 = 10. 806 and 10. 455, both P 〈 0. 05 ）. Conclusions Preoperative chemoradiation can influence rectal cancer eell＇s apoptosis and treatment effect by changing Bel- XL and Bax expression. Bcl-XL downregulation and Bax upregulation have shown important function in colorectal cancer cell apoptosis which induced by preoperative chemoradiation, it can also improve the effection of ehemoradiation in rectal eaneer.