Effect of thoracoscopic right upper mediastinal dissection for left lung cancer-Especially about micrometastasis to lymph nodes-

背景：I期非小细胞左肺癌患者生存率不高，可能是由于对侧纵隔淋巴结累及的高发。在这项研究中，我们使用实时定量逆转录聚合酶链反应（RT-PCR）方法回顾性研究了I期左肺癌患者右上纵隔淋巴结的隐匿性微转移。材料与方法：21例临床I期非小细胞左肺癌行VATS肺叶切除术及双侧纵隔淋巴结清扫术（BMD）。比较27例左单侧纵隔淋巴结清扫（UMD）患者的临床资料和生存率。采用细胞角蛋白19 mRNA RT-PCR法检测隐匿性微转移灶。结果：BMD与UMD患者的手术时间、出血量、胸管引流时间、术后住院时间无显著差异。病理性N2病1例。20例患者有pN0病。9/21（42）例右侧纵隔淋巴结微转移。8%)患者。在7/9（77 /9）中观察到跳过微转移到N3水平淋巴结而未累及n1和N2淋巴结。8%)患者。中位随访时间为13年，BMD患者均存活，无复发。9个月。BMD患者的总体3年生存率和无病3年生存率与UMD患者无显著差异。结论：胸腔镜下右上纵隔清扫术治疗左肺癌是安全可行的。在我们的初步研究中，隐匿性微转移到N3水平淋巴结经常发生在临床N0期非小细胞左肺癌患者中。可能，隐匿性微转移至N3水平淋巴结的患者术后生存率并不差。需要进一步的跟进和工作。

Background : Survival of patients with stage I non-small cell left lung cancer is not sufficient, probably, because of high incidence of the contralateral mediastinal node involvement. In this study, we investigated retrospectively occult micrometastases to the right upper mediastinal nodes in patients with stage I left lung cancer using a real-time quantitative reverse transcription-polymerase chain reaction(RT-PCR) method. Material and methods : 21 patients with clinical stage I non-small-cell left lung cancer underwent VATS lobectomy and bilateral mediastinal lymph node dissection(BMD). Clinical data and survival of patients with BMD were compared with those of 27 left-unilateral mediastinal node dissection(UMD). Occult micrometastases were detected using cytokeratin 19 mRNA RT-PCR method. Results : The operative time, blood loss, duration of chest tube drainage, and duration of postoperative hospital stay were not different between BMD and UMD patients. Pathological N2 disease was one patients. 20 patients had pN0 disease. Nodal micrometastases of right mediastinum were detected in 9/21(42. 8%) patients. Skip micrometastases to the level N3 nodes without the N1and N2 node involvement was observed in 7/9(77. 8%) patients. Patients with BMD are all alive and have no recurrence during median follow-up period of 13. 9 months. Overall 3-year survival and disease free 3-year survival of BMD patients were not significant difference from those of UMD patients. Conclusion : Thoracoscopic right upper mediastinal dissection for left lung cancer is safe and feasible. In our preliminary study, occult micrometastases to the level N3 nodes occurred frequently in patients with clinical N0 stage I non-small cell left lung cancer. Possibly, postoperative survival of patients with occult micrometastases to the level N3 node is not poor. Further follow up and work are needed.