探讨直肠癌患者组织中P53的表达及其与术前同步放化疗病理反应敏感性的关系。

选取2012年5月至2013年11月于海南医学院第二附属医院就诊的直肠腺癌患者82例，患者放化疗结束后4~6周行直肠切除术，依据RCRG评价同步放化疗敏感性，检测记录放化疗前后P53蛋白阳性细胞所占比例，单因素分析和Logistic多因素回归分析术前同步放化疗病理缓解的影响因素，并对患者进行随访，对患者的生存时间与放化疗后病理RCRG分级进行生存分析。

放化疗后完全缓解（G1）38例（46.34%），放化疗敏感（G1+G2）65例（79.29%）。放化疗后P53蛋白含量明显下降（Z=-3.611，P<0.05）；放化疗前P53高表达（OR=1.853，95% CI：1.144~3.002，P=0.012）、临床降期（OR=1.982，95% CI：1.268~3.098，P=0.003）为直肠癌术前放化疗敏感性的独立危险因素。所有患者中位生存时间为（46.3±1.4）个月，其中G1+G2患者中位生存时间为（71.3±2.4）个月，放化疗不敏感（G3）患者中位生存时间为（38.2±2.1）个月，两组总生存时间比较，差异有统计学意义（P=0.036）。

直肠癌放化疗后肿瘤组织中P53蛋白表达显著下降，且P53高表达的直肠癌患者术前放化疗后敏感性更高。P53的表达水平对局部晚期直肠癌患者术前新辅助放化疗临床决策有一定指导意义。

To investigate the expression of P53 in rectal cancer tissues and its relationship with the sensitivity of preoperative concurrent chemoradiotherapy.

Eighty-two cases of rectal adenocarcinoma were selected from May 2012 to November 2013 in the Second Affiliated Hospital of Hainan Medical College. Patients underwent rectal resection 4-6 weeks after the end of preoperative chemoradiotherapy. The sensitivity of concurrent chemoradiotherapy was evaluated according to RCRG. The proportion of P53 protein positive cells before and after chemoradiotherapy was detected. The influencing factors of pathological remission of preoperative concurrent chemoradiotherapy were analyzed by Logistic regression. The patients were followed up to evaluate the survival of different pathological RCRG classification.

Thirty-eight cases (46.34%) had complete remission (G1) and sixty-five cases (79.29%) were sensitive to chemoradiotherapy (G1+G2). The content of P53 protein decreased significantly after radiotherapy and chemotherapy (Z=-3.611, P<0.05). High expression of P53 (OR=1.853, 95% CI: 1.144-3.002, P=0.012), clinical decline (OR=1.982, 95% CI: 1.268-3.098, P=0.003) were independent risk factors for preoperative chemoradiotherapy sensitivity of rectal cancer. The median survival time of all patients was (46.3±1.4) months, of which the median survival time of (G1+G2) patients was (71.3±2.4) months, and the median survival time of G3 patients was (38.2±2.1) months. The difference between survival time and pathological effective course after radiotherapy and chemotherapy was statistically significant (P=0.036).

P53 protein expression in rectal cancer tumor tissues is significantly decreased after chemoradiotherapy. Patients with high expression of P53 are more sensitive to the treatment, which displays good prognosis value to assess the clinical response of neoadjuvant radiotherapy and chemotherapy in patients with locally advanced rectal cancer.