中文摘要：

目的 探讨局部晚期直肠癌术前三维适形放疗同期化疗后病理完全缓解（pCR）患者术后辅助化疗的价值。方法 2005—2010年本中心收治的同期放化疗后术后病理证实pCR的 49例患者,其中行术后辅助化疗 38例,未行术后辅助化疗 11例。比较二者疗效。结果 随访率100%,随访时间满 3年者 22例。全组 3年总生存率、无复发生存率和癌症特异生存率分别为92%、90%和95%,术后有与无辅助化疗的分别为90% 与100%（χ2=0.05,P=0.818）、92%与80%（χ2=1.00,P=0.316）、94%和100%（χ2=0.31,P=0.581）。全组 3年复发率为8%,术后有、无辅助化疗的分别为8%、9%（χ2=1.00,P=0.316）。结论 局部晚期直肠癌术前三维适形放疗同期化疗后获pCR患者累计复发率低,术后辅助化疗并未提高疗效,因随诊期短、病例数不多,其价值需进一步临床随机对照研究加以甄别。

英文摘要：

Objective To investigate the value of postoperative adjuvant chemotherapy in the patients with locally advanced rectal cancer who achieved a pathologically complete response （pCR） after operation following concurrent three-dimensional conformal radiotherapy （3DCRT） and chemotherapy. Methods Retrospective analysis was performed on the clinical records of 49 patients with locally advanced rectal cancer, who achieved a pCR after operation following concurrent 3DCRT and chemoradiotherapy in our center from August 2005 to October 2010. These patients were divided into group A （n=38） that received postoperative adjuvant chemotherapy and group B （n=11） that did not receive postoperative adjuvant chemotherapy. The two groups were compared in terms of treatment outcome. Results The follow-up rate was 100%;22 patients were followed up for at least 3 years. The 3-year overall survival rate, relapse-free survival rate, and cancer-specific survival rate of all patients were 92%, 90%, and 95%, respectively;group A and group B had overall survival rates of 90% and 100%（χ2=0.05, P=0.818）, relapse-free survival rates of 92% and 80%（χ2=1.00, P=0.316）, and cancer-specific survival rates of 94% and 100%（χ2=0.31, P=0.581）. The 3-year recurrence rate of all patients was 8%;group A and group B had 3-year recurrence rates of 8% and 9%（χ2=1.00, P=0.316）. Conclusions The patients with locally advanced rectal cancer who achieve a pCR after operation following concurrent 3DCRT and chemotherapy have low cumulative recurrence rate. Postoperative adjuvant chemotherapy does not improve the clinical outcomes in these patients. Because of short follow-up period and small number of subjects in this study, the effect of postoperative adjuvant chemotherapy needs to be further investigated in randomized controlled clinical trial.