探讨中低位直肠癌术前新辅助治疗后不同等待时间对术后病理及预后的影响。

回顾性分析2013年1月~2018年12月期间于江苏省人民医院行新辅助放化疗的77例进展期中低位直肠癌患者临床资料，按照新辅助治疗后术前等待时间分为Ⅰ组43例（6~8周）和Ⅱ组34例（9~12周），比较两组术后病理及预后情况。

两组患者新辅助前的一般资料如性別、年龄、cTNM分期及CEA水平等比较差异均无统计学意义（P>0.05）。术后病理结果提示：Ⅱ组术后病理淋巴结阳性率显著低于Ⅰ组（20.6% vs. 46.5%，P=0.018）。Ⅰ组和Ⅱ组pCR率分别为18.6%和17.6%，二者差异无统计学意义（χ²=0.012，P=0.914）。Ⅰ组共有14例患者（32.6%，14/43）肿瘤消退明显，仅剩下少量镜下癌灶或无肿瘤残留，Ⅱ组共有13例患者（38.2%，13/34）肿瘤消退明显，两组比较差异无统计学意义（Z=-0.702，P=0.483）。两组术后并发症发生率及远期肿瘤复发及转移差异无统计学意义（P>0.05）。

延长新辅助放化疗至手术的时间间隔至9~12周较6~8周能进一步降低淋巴结的阳性率，但对pCR率及肿瘤消退分级评分并无影响。对术后短期并发症发生情况以及长期复发及转移等情况也未产生较大影响。延期手术对患者来说利弊共存，因此应根据患者病情制定个体化治疗策略。

To investigate the effect of different waiting time on pathology and prognosis of low rectal cancer after preoperative neoadjuvant chemoradiotherapy.

Seventy-seven patients who received rectal cancer surgery following neoadjuvant therapy in Jiangsu Province Hospital from January 2013 to December 2018 were retrospectively analyzed. According to the preoperative waiting time after neoadjuvant therapy, forty-three patients were divided into groupⅠ(6~8 weeks) and 34 patients in group Ⅱ(9~12 weeks). The baseline characteristics and surgical outcomes of the two groups were analyzed.

There was no significant difference in general data such as sex ratio, age, cTNM stage and CEA level between the two groups before neoadjuvant therapy (P>0.05). Postoperative pathological results showed that the positive rate of pathological lymph nodes in group Ⅱ was significantly lower than that in groupⅠ (20.6% vs. 46.5%, P=0.018). The pCR rates of group Ⅰ and group Ⅱ were 18.6% and 17.6%, respectively (χ²=0.012, P=0.914) . In group Ⅰ, 14 patients (32.6%, 14/43) had obvious regression of tumors. In group II, 13 patients (38.2%, 13/34) had obvious regression of tumors. There was no significant difference between the two groups (Z=-0.702, P=0.483) . There was no significant difference in the incidence of postoperative complications and long-term recurrence and metastasis between the two groups (P>0.05).

Extending the interval between neoadjuvant chemoradiotherapy and surgery to 9~12 weeks can further reduce the positive rate of lymph nodes compared with 6~8 weeks, but there is no significant difference in the pCR rate and the grade of tumor regression. There was no significant effect on the occurrence of short-term complications and long-term recurrence and metastasis. Delayed interval time has both advantages and disadvantages for patients, so individualized treatment strategies should be formulated according to condition.