肿瘤距肛缘距离和手术方式对进展期低位直肠癌新辅助治疗生存预后的影响

Effects of tumor distance from anal verge and types of operations on survival outcomes for low rectal cancer after neoadjuvant chemoradiotherapy

目的：了解进展期低位直肠癌新辅助治疗后肿瘤距肛缘距离、手术方式对生存预后的影响。方法回顾性分析北京协和医院2005至2012年收治的接受新辅助治疗的中低位直肠癌患者135例，其中男79例，女56例；平均年龄（58±12）岁；肿瘤距肛缘平均（5.2±2.1） cm。分析性别、年龄、肿瘤距肛缘距离、手术方式、T分期降期情况、治疗后淋巴结状况等因素对3年无病生存（ DFS ）率的影响。结果本组患者总体3年DFS率为85.2％（115/135）。135例患者中95例行括约肌保留完整的术式，其中前切除术79例、经前会阴超低位直肠前切除术（ APPEAR）12例、Hartmann术3例和结肠肛管吻合术（Parks术）1例；40例患者部分或完全切除括约肌，其中经腹会阴联合切除术（APR）39例、内括约肌切除术（ISR）1例。保留括约肌与切除括约肌患者的DFS差异无统计学意义[85.3％（81/95）比85.0％（34/40），χ2＝0.000， P＝0.985]。肿瘤距肛缘距离2～3、4～5、6～7 cm者DFS分别为81.5％（22/27）、82.5％（47/57）、95.1％（39/41），虽有升高趋势，但前者与后二者比较差异无统计学意义（χ2＝3.111、3.522，P＝0.078、0.061）；6～7 cm的保留括约肌手术组的3年DFS率与2～3 cm的括约肌切除手术组差异无统计学意义[95.0％（38/40）比81.0％（17/21），χ2＝2.864，P＝0.091]，但明显高于4～5 cm的保留括约肌手术组[79.5％（31/39），χ2＝4.227，P＝0.039]。多因素生存分析提示，仅治疗后淋巴结状况是生存预后的独立影响因素（ Wald＝4.454，P＝0.035）。结论新辅助治疗后的术后淋巴结和侧切缘状况仍然是影响生存预后的主要因素；同时也存在肿瘤位置越低，生存预后越差的趋势。对于距离肛缘4～5 cm的直肠癌，虽然能够保留肛门，但没有从生存期中获益。

Objective To assess the effects of neoadjuvant chemoradiotherapy on survival outcomes of low rectal cancer after sphincter-preserving or removing surgery.Methods A total of 135 patients with rectal cancer within 10 cm from anal verge after neoadjuvant chemoradiotherapy were enrolled into this retrospective study from 2005 to 2012 at a single institute.There were 79 males and 56 females with a mean age of（58 ±12）years and an average distance of （5.2 ±2.1）cm from anal verge.The effects of gender, age, distance of tumor from anal verge , surgical procedure , T-stage downstaging , lateral resection margin and post-treatment lymphatic node status on 3-year disease-free survival （ DFS ） were examined.Results The overall 3-year DFS was 85.2%（ 115/135 ）.Among 95 sphincter-preserving operations , there were anterior resection （ n=79 ） , anterior perineal plane for ultra low anterior resection （ APPEAR ） technique （n=12）, Hartmann procedure （ n =3） and Parks procedure （ n =1）.Among 40 sphincter-removing operations, there were abdominoperineal resection （APR） procedure （n=39） and intersphincteric resection （ ISR） （ n=1 ）.The survival of patients undergoing sphincter-preserving or removing procedures did not＆amp;nbsp;differ in 3-year DFS （85.3%（81/95） vs 85.0%（34/40）, χ2 =0.000, P =0.985）.Lateral resection margin and post-treatment lymphatic node status significantly affected DFS.The differential level from anal verge showed a trend of close relationship to 3-year DFS （81.5%（22/27）for 2-3 cm, 82.5%（47/57） for 4-5 cm vs 95.1%（39/41） for 6 -7 cm）, but without statistic significance （χ2 =3.111, 3.522; P=0.078, 0.061）.The survival rate for patients with sphincter-preserving at 6 -7 cm from anal verge was significantly higher than that at 4-5 cm（95.0%（38/40） vs 79.5%（31/39）,χ2 =4.227,P=0.039）, but showed no differences to that with sphincter-removing at 2-3 cm from anal verge （ 81.0%（ 17/21 ） ,χ2 =2.864,P=0.091）.The multivariate analysis showed that post-treatment lymphatic node status was the only prognostic factor to 3-year DFS （ Wald =4.454,P=0.035）.Conclusions Lateral resection margin and post-treatment lymphatic node status play an important role on DFS for patients with low rectal cancer after neoadjuvant chemoradiotherapy.The distance from anal verge is correlated with 3-year disease-free survival.Patients with tumor at 4 -5 cm from annal verge can not benefit for survival when they get sphincter -preserving operations.