直肠腺癌中血管内皮生长因子和细胞增生核抗原的表达及其与放化疗敏感性的关系

Correlation of VEGF and Ki67 expression with sensitivity to neoadjuvant chemoradiation in rectal adenocarcinoma

目的探讨血管内皮生长因子（VEGF）和细胞增生核抗原（Ki67）在直肠腺癌中的表达及其与放化疗敏感性的关系。方法采用免疫组化二步法，检测接受新辅助放化疗的32例直肠腺癌患者的活检标本及手术切除标本中VEGF和Ki67的表达。结果VEGF在直肠腺癌中的表达与肿瘤侵袭程度、淋巴结转移和TNM分期有关（均P〈0．05），与患者的性别、年龄、肿瘤大小及病理类型无关（均P〉0．05）；VEGF阴性表达者对放化疗敏感（P=0．016）；新辅助放化疗后，VEGF的表达升高（P〈0．05）。Ki67在直肠腺癌中的表达与淋巴结转移有关（P=0．028），与患者的性别、年龄、肿瘤大小、病理类型、TNM分期和侵袭程度无关（均P〉0．05）；Ki67阴性和低表达者对放化疗敏感（P=0．032）；新辅助放化疗后，Ki67的表达有下降趋势，但并无统计学意义（P〉0．05）。结论VEGF和Ki67的表达可作为预测直肠腺癌患者对新辅助放化疗敏感性的参考指标。

Objective To investigate the correlation of expression of vascular endothelial growth factor （VEGF） and proliferating cell nuclear antigen （Ki67） with sensitivity to neoadjuvant chemoradiation in rectal adenocareinoma. Methods Samples of pretreatment biopsies and the resected specimens after neoadjuvant therapy in 32 patients with rectal adenocarcinoma were collected, and the expression of Ki67 and VEGF were detected by immunohistochemistry using specific antibodies. The correlation of Ki67 and VEGF expression with clinicopathological factors were analyzed. Results The level of VEGF expression was significantly correlated with lymph node metastasis （ P = 0. 033 ）, depth of tumor invasion （ P = 0.007 ） and TNM stage （P=0.016）, but not with histological type, tumor size, age and gender of the patients （P 〉 0.05 ）. However, VEGF expression was found to be negatively and significantly correlated with the sensitivity to neoadjuvant chemoradiation （ P = 0. 016 ）, and a transient increase of VEGF expression was detected in the resected specimens after neoadjuvant therapy （P = 0.035 ）. Ki67 labeling index （Ki67-LI） was found to be significantly correlated with lymph node metastasis （P = 0. 028 ）, but not with tumor size, age and gender of the patients （ P 〉 0.05 ）. It was also found that tumors with lower Ki67-LI expression were more sensitive to neoadjuvant therapy than that with higher expression of Ki67-LI （ P = 0.032）. In contrast with VEGF, the Ki67 expression level decreased after neoadjuvant therapy, but no statistical significance was found between pretreatment and posttreatment specimens （P 〉 0.05）. Conclusion The preliminary results of this study demonstrate that the expression of VEGF and Ki67 in pretreatment biopsy of rectal adenocarcinoma may be used as a biomarker to predict tumor response to neoadjuvant chemoradiation.