title: [Relationship between tumor size and lymph node metastasis in squamous cell carcinoma and adenocarcinoma of the lung].
abstract: BACKGROUND
  Lymphatic dissemination is the main approach of metastasis in lung cancer, and it is also an important prognostic factor. The aim of this study is to explore the relationship between tumor size and lymph node metastasis in squamous cell carcinoma and adenocarcinoma of the lung.
  
  
  METHODS
  A total of 240 patients diagnosed as squamous cell carcinoma and adenocarcinoma were studied. The relationship between tumor size and lymph node metastasis was analyzed.
  
  
  RESULTS
  Lymph node metastasis rate in maximum diameter (d)≤2cm, 2cm < d≤3cm, 3cm < d≤6cm, 6cm < d≤10cm, and d > 10cm groups was 50.0%, 35.1%, 52.8%, 52.1% and 71.4%, respectively. There was no correlation between tumor size and lymph node metastasis (r=0.10, P > 0.05). Lymph node metastasis occurred more frequently in adenocarcinoma (58.8%) than that in squamous cell carcinoma (42.9%) (P < 0.05). Mediastinal lymph node metastasis was found in 7 patients (16.3%) with d≤3cm, who were all diagnosed as moderate or poor differentiation.
  
  
  CONCLUSIONS
  Lymph node metastasis is not related to tumor size. Lymph node metastasis occurs more frequently in adenocarcinoma than it does in squamous cell carcinoma. Mediastinal lymph node metastasis can be found in tumor with d≤3cm, and differentiation grade may play an important role in lymph node metastasis.
authors.affiliation: Department of Thoracic and Cardiac Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R.China.
authors.forename: Tiecheng
authors.initials: T
authors.lastname: Pan
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zheng
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Yingxiong
authors.initials: Y
authors.lastname: Tang
authors.forename: Youmin
authors.initials: Y
authors.lastname: Pan
authors.forename: Xiang
authors.initials: X
authors.lastname: Wei
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
authors.forename: Ni
authors.initials: N
authors.lastname: Zhang