超低位直肠癌新辅助治疗后淋巴结分布及转移规律

目的探讨新辅助治疗对超低位直肠癌淋巴结转移及其微转移规律及分布的影响，为手术方式的选择提供依据。方法运用大组织切片苏木精．伊红染色和组织芯片CK20染色方法，研究超低位直肠癌新辅助治疗组（21例）与直接手术组（23例）行Miles手术后的大体标本。结果新辅助治疗组21例患者直肠系膜共检获淋巴结138枚．其中转移淋巴结39枚，微转移12枚：7例为淋巴结癌转移。2例为淋巴结微转移，6例为病理完全缓解。直接手术组23例患者的直肠系膜共检获淋巴结415枚，其中转移淋巴结169枚，微转移59枚：12例为淋巴结癌转移，4例为淋巴结微转移。两组直肠系膜外带与前区的转移淋巴结分别占21．5％（11／51）与29．0％（49／169）、17．6％（9／51）与17．2％（29／169）。坐骨直肠窝转移淋巴结分别占该区总淋巴结的25．0％（3／12）与22．2％（8／36），该区淋巴结转移或微转移者分别占总病例数的4．8％（1／21）与13．0％（3／23）。结论新辅助治疗影响超低位直肠癌区域淋巴结的转移与分布．新辅助治疗组肛门括约肌累及较直接手术组显著降低。坐骨直肠窝内极少发生淋巴结转移，Miles手术作为超低位直肠癌新辅助治疗后标准术式的价值应重新评估。

Lymph nodes distribution and metastatic pattern of ultra-low rectal cancer after neoadjuvanttherapy

Objective To investigate the lymph nodes distribution and metastatic pattern of the ultralow rectal cancer after neoadjuvant therapy. Methods A total of 21 rectal cancer gross specimen after neoadjuvant therapy and 23 rectal cancer gross specimen without neoadjuvant therapy were investigated by whole mount section and tissue microarray techniques with CK20. All the patients were treated by abdominoperineal resection. Results There were 138 lymph nodes retrieved from the mesorectum in the neoadjuvant group including 39 metastatic lymph nodes and 12 micrometastatic lymph nodes. Among these nodes, there were 7 rectal cancer cases with lymph nodes and 2 cases with micrometastatic lymph nodes, and 6 cases had pathological complete remission. There were 415 lymph nodes retrieved from the mesorectum in the group without neoadjuvant therapy including 169 metastatic lymph nodes and 59 micrometastatic lymph nodes. Among these nodes, there were 12 rectal cancer cases with lymph nodes and d cases with micrometastatic lymph nodes. The proportions of metastatic lymph nodes in outer zone between the two groups were 21.5% and 29.0%, and those in prezone were 17.6% and 17.2% respectively. The ratio of metastatic lymph nodes in ischiorectal fossa between the two groups were 25.0% vs. 22.2% respectively. The rate of metastatic or micrometastatic lymph nodes cases between the two groups were 4.8% vs. 13.0% respectively. Conclusions The lymph nodes distributionand metastatic pattern of the ultralow rectal cancer are affected by neoadjuvant therapy. The proportions of the anal sphincter invasion and metastatic or micrometastatic lymph nodes in ischiorectal fossa are lower after neoadjuvant therapy. Ahdominoperineal resection as the standard treatment of the ultralow rectal cancer after neoadjuvant therapy should be reevaluated.