Risk factors for recurrence after complete resection of pathological stage N2 non-small cell lung cancer.
BACKGROUND
Tumor recurrence is the most common cause of treatment failure, especially after complete resection of pathological stage N2 non-small cell lung cancer (NSCLC). In this study, we investigated the clinicopathological characteristics in order to identify independent risk factors for postoperative recurrence.


METHODS
Between January 2001 and December 2013, 96 patients who underwent surgical resection for pathological N2 NSCLC were retrospectively reviewed. Recurrence-free survival (RFS) was calculated by the Kaplan-Meier method to explore risk factors, while the Cox proportional hazard model was used to assess independent predictors.


RESULTS
The median and five-year RFS rates were 15 months and 27.4%, respectively. Univariate analysis showed a significantly poorer prognosis for non-regional N2 metastasis, more than three metastatic N2 lymph nodes, multiple N2 station, and multiple N2 zone involvement. Multivariate analysis demonstrated that non-regional N2 metastasis (hazard ratio [HR] 1.857, 95% confidence interval [CI] 1.061-3.249, P = 0.030) and more than three metastatic N2 lymph nodes (HR 2.555, 95% CI 1.164-5.606, P = 0.019) were independent risk factors for RFS. Additionally, the incidence of non-regional N2 metastasis was higher in patients with a primary tumor in the left lower (57.1%) or right lower lobe (48.1%), followed by left upper (31.8%), right middle (14.3%) and right upper lobe (7.7%).


CONCLUSIONS
The combination of the distribution and number of metastatic N2 lymph nodes provides a more accurate prediction for N2 NSCLC regarding recurrence. Non-regional N2 metastasis could occur with a primary tumor in any lobe, but occurs more frequently in the lower lobe.
Division of Thoracic Surgery, China-Japan Friendship Hospital Beijing, China.
Guangliang
G
Qiang
Division of Thoracic Surgery, China-Japan Friendship Hospital Beijing, China.
Chaoyang
C
Liang
Division of Thoracic Surgery, China-Japan Friendship Hospital Beijing, China.
Qiduo
Q
Yu
Division of Thoracic Surgery, China-Japan Friendship Hospital Beijing, China.
Fei
F
Xiao
Division of Thoracic Surgery, China-Japan Friendship Hospital Beijing, China.
Zhiyi
Z
Song
Division of Thoracic Surgery, China-Japan Friendship Hospital Beijing, China.
Yanchu
Y
Tian
Division of Thoracic Surgery, China-Japan Friendship Hospital Beijing, China.
Bin
B
Shi
Division of Thoracic Surgery, China-Japan Friendship Hospital Beijing, China.
Deruo
D
Liu
Division of Thoracic Surgery, China-Japan Friendship Hospital Beijing, China.
Yongqing
Y
Guo
Mediastinal lymph node; non-small cell lung cancer; recurrence; risk factors; stage N2