胸段食管癌的淋巴结转移规律及其对确定术后放射治疗靶区范围的价值

Characteristics of the lymph node metastases and influencing factors and their value in target region delineation in postoperative radiotherapy for thoracic esophageal carcinoma

目的 分析胸段食管癌淋巴结转移的规律及其影响因素,探讨食管癌术后放疗的靶区范围.方法 收集763例接受根治性切除的胸段食管癌患者的临床病理资料,分析淋巴结转移规律及影响因素.结果 763例胸段食管癌患者共清除淋巴结5846枚,病理证实转移711枚,转移度为12.2%;出现淋巴结转移者297例,转移率为38.9%.胸上段癌淋巴结转移率为28.5%,明显低于胸中段癌（38.8%）和胸下段癌（43.4%）.胸上段癌以锁骨上和气管旁淋巴结的转移度和转移率最高.胸中段癌的上行和下行转移均存在,上行主要转移至锁骨上、气管旁和食管旁,下行主要转移至贲门和胃左动脉旁.胸下段癌则主要向食管旁、贲门和胃左动脉旁转移,其中胃左动脉旁的转移度和转移率均显著高于胸上段癌和胸中段癌（均P〈0.01）.采取左胸单切口的592例患者中,胸上、中、下段癌的淋巴结转移率分别为37.0%、37.9%和41.4%,差异无统计学意义（P=0.715）.多因素Logistic回归分析表明,病变长度、浸润深度、脉管瘤栓和远处转移是影响胸段食管癌淋巴结转移的主要因素（均P〈0.05）.结论 临床上可以根据食管癌的病变长度、浸润深度、脉管瘤栓和远处转移选择需行术后预防照射的患者,根据不同病变部位、不同手术方式及TNM分期,确定术后预防照射的靶区范围.

Objective To explore the distribution of lymph node metastases, to analyze the cliniopathologic factors of thoracic esophageal carcinoma after curative resection, and to provide the criteria of irradiated region delineation in radiotherapy for esophageal carcinoma. Methods The clinicopathological data of 763 patients who underwent esophagecotomy from Jun 2002 to Jun 2006 were retrospectively analyzed. The regularity of lymph node metastases of thoracic esophageal cancer and clinicopathological factors were stratified and analyzed with SPSS13.0 software. Results Of the 763 patients, a total of 5846 lymph nodes were dissected with an average of 7.7 lymph nodes in each case. Metastatic lymph nodes were 711, the ratio of metastatic lymph node was 12.2% , and 297 patients had lymph node involved, the lymph node metastasis rate was 38.9%. The metastatic lymph nodes of upper-thoracic esophagus were mainly observed in the supraclavicular and paratracheal regions （P〈0.05）, the metastatic lymph nodes of middlethird thoracic esophagus were bidirectional, and those of the lower-third thoracic esophagus mainly metastasized to the regions adjacent to the esophagus, gastric cardia and gastric artery （P〈 0.05 ）. Both the metastasis ratio and rate of lymph nodes adjacent to the gastric artery in the lower-thoracic esophageal cancer were significantly higher than those in the middle-third and upper-third thoracic esophageal cancers （ P =0.007, P = 0.001）. The multiple factors logistic regression analysis showed that tumor length, depth of tumor invasion, vascular tumor emboli and distant metastasis were major factors for lymphatic metastasis （P〈0.01）. For the whole group of patients the lymph node metastatic rate was 28.5% in upper-thoracic esophageal cancer, significantly lower than 38.8% of the lower-thoracic esophageal cancer （P =0.039） and 43.4% in the middle-thoracic esophageal cancer （P=0.010）. However, the lymph node metastatic rates were 37.0% , 37.9% and 41.4% in the upper- , middle- and lower-thoracic esophageal cancers of the 592 cases receiving left chest notches , with a non-significant difference among them （ P=0.715 ） . Conclusion The lesion length, depth of tumor invasion, vascular tumor embolus and distant metastasis are the most important parameters for lymph node metastases. Operative modes have obvious influence on the distribution of regional lymph node metastases. Therefore, in the clinical management, a postoperative prophylactic radiotherapy may be selected according to the tumor length, depth of tumor invasion, vascular tumor embolus and distant lymph node metastasis.