[Risk factor analysis of mediastinal lymph node metastasis in non-small cell lung cancer patients and the strategy of mediastinoscopy prior to surgery].
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 cases pathologically proven and clinically staged I-III were enrolled in the study. Of the 152 cases, there were 118 males and 34 females. Age ranged 24-79 years old and the median age was 58. All cases underwent CT and mediastinoscopy 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 <1 cm). 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 stage I (cT1-2N0M0) 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 adenocarcinoma or mediastinal lymph nodes > or =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 > or =1 cm in the shortest axis on CT scan mandates preoperative mediastinoscopy. Adenocarcinoma also indicates mandatory mediastinoscopy even with negative mediastinal or hilar lymph nodes on CT scan.
Wang
Xin
X
Department of Thoracic Surgery, Sun Yet-sen University Cancer Center, Guangzhou 510060, China. wangxin7@mail.sysu.edu.cn
Zheng
Lie
L
Zhang
Shi-Yi
SY
Xie
Ze-Ming
ZM
Yu
Hui
H
Su
Xiao-Dong
XD
Wang
Jun-Ye
JY
Huang
Zhi-Fan
ZF
Yang
Ming-Tian
MT
Rong
Tie-Hua
TH
D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D002272:Carcinoembryonic Antigen / Q000097:blood; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D016015:Logistic Models; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008481:Mediastinoscopy; D008482:Mediastinum; D008875:Middle Aged; D009367:Neoplasm Staging; D057234:Preoperative Period; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D055815:Young Adult
D002272:Carcinoembryonic Antigen