非小细胞肺癌纵隔淋巴结转移危险因素分析及术前纵隔镜检查的应用策略

Risk factor analysis of mediastinal lymph node metastasis in non-small cell lung cancer patients and the strategy of mediastinoscopy prior to surgery

目的探讨纵隔镜技术评估非小细胞肺癌（NSCLC）术前纵隔淋巴结状态（是否存在转移）的临床应用策略。方法2000年10月至2007年6月，对临床连续收治的经病理确诊的临床分期为Ⅰ～Ⅲ期的NSCLC患者152例，分别采用CT和纵隔镜技术评估纵隔淋巴结状态。根据纵隔淋巴结最终病理结果，计算CT下纵隔怖门淋巴结阴性NSCLC的纵隔镜检查阳性率和实际纵隔淋巴结转移发生率。以患者性别、年龄、肿瘤部位、病理类型、肿瘤T分期、肿瘤类型（中央型或外周型）、CT下纵隔淋巴结大小和血清癌胚抗原（CEA）水平等作为预测因子，进行纵隔淋巴结转移危险因素的单因素和多因素分析。结果69例CT下纵隔肺门淋巴结阴性NSCLC，纵隔镜检查阳性8例，阳性率为11．6％；实际纵隔淋巴结转移14例，发生率为20．1％。62例临床Ⅰ期（CT1～2NOM0）NSCLC，纵隔镜检查阳性7例，阳性率为11．3％；实际纵隔淋巴结转移12例，发生率为19．4％。对全部152例NSCLC患者纵隔淋巴结转移危险因素的分析结果显示，病理类型和CT下纵隔淋巴结大小是纵隔淋巴结转移的独立危险因素。对69例CT下纵隔肺门淋巴结阴性NSCLC患者纵隔淋巴结转移危险因素的分析结果显示，病理类型是纵隔淋巴结转移的独立危险因素。结论对于CT下纵隔淋巴结短径≥1cm的NSCLC患者，术前必须进行纵隔镜检查；对于腺癌患者，即使是CT下纵隔肺门淋巴结短径〈1cm，术前也应该进行纵隔镜检查。

Objective To discuss the strategy of mediastinoscopy for the evaluation of mediastinal lymph node status （metastasis or not） of non-small cell lung cancer （NSCLC） prior to surgery. Methods From October 2000 to June 2007, 152 consecutive NSCLC eases pathologically proven and clinically staged Ⅰ-Ⅲ were enrolled in the study. Of the 152 eases, there were I18 males and 34 females. Age ranged 24-79 years old and the median age was 58. All eases underwent CT and mediastinoseopy for the evaluation of mediastinal lymph node status prior to surgery. Compared with the results of final pathology, the positive rate of mediastinoscopy and the prevalence of mediastinal lymph node metastasis were calculated in the NSCLC patients with negative mediastinal or hilar lymph nodes on CT scan （ the shortest axis of mediastinal or hilar lymph nodes 〈 1cm） . Clinical characteristics used as predictive factor including sex, age, cancer location, type of pathology, T status, cancer type （ central or peripheral ）, size of mediastinal lymph nodes （ the shortest axis 〈 1 cm or ≥1 cm ） on CT scan and serum CEA level were analyzed by univariate and multivariate analysis with Binary logistic regression model to identify risk factors of mediastinal metastasis. Results The positive rate of mediastinoscopy was 11.6% （8/69） and the prevalence of mediastinal metastasis was 20. 1% （14/69） in NSCLC with negative mediastinal or hilar lymph nodes on CT scan respectively. In clinical stageⅠ （CT1-2NOM0） NSCLC the positive rate of mediastinoscopy was 11.3% （7/62）, N2 accounting for 6.5% （4/62） and N3 4.8% （3/62）, respectively; and the prevalence of mediastinal lymph node metastasis was 19.4% （12/62）, N2 ccounting for 14.6% （9/62） and N3 4.8% （3/62）, respectively. In the whole group both univariate and multivariate analysis showed that adenoearcinoma or mediastinal lymph nodes ≥ 1 cm in the shortest axis on CT scan was an independent risk factor to predict mediastinal lymph node metastasis. In NSCLC with negative mediastinal or hilar lymph nodes on CT scan both univariate and multivariate analysis showed that adenocarcinoma was a predictor of mediastinal lymph node metastasis. Conclusion We recommend the policy of routine mediastinoscopy in NSCLC prior to surgery if the mediastinal staging was only based on CT scan. Mediastinal lymph nodes ≥ 1 cm in the shortest axis on CT scan mandates preoperative mediastinoscopy. Adenocareinoma also indicates mandatory mediastinoscopy even with negative mediastinal or hilar lymph nodes on CT scan.