Selection of proper candidates with resected pathological stage IIIA-N2 non-small cell lung cancer for postoperative radiotherapy.
BACKGROUND
To establish a prediction model in selecting fit patients with resected pIIIA-N2 non-small cell lung cancer (NSCLC) for postoperative radiotherapy (PORT), and evaluate the model in clinical practice.


METHODS
Between January 2003 and December 2005, 221 patients with resected pIIIA-N2 NSCLC were retrospectively analyzed. The effect of PORT on overall survival (OS) of patients with different clinicopathological factors was evaluated and the results were used to establish a prediction model to select patients fit for PORT.


RESULTS
Compared with the control, PORT significantly improved the OS of patients with a smoking index ≤400 (P = 0.033), cN2 (P = 0.003), pT3 (P = 0.014), squamous cell carcinoma (SCC) (P = 0.013), or ≥4 positive nodes (P = 0.025). Patients were divided from zero to all five factors into low, middle, and high PORT index (PORT-I) groups (scored 0-1, 2, and 3-5, respectively). PORT did not improve OS (3-year, P = 0.531), disease free survival (DFS) (P = 0.358), or loco-regional recurrence free survival (LRFS) (P = 0.412) in the low PORT-I group. PORT significantly improved OS (P = 0.033), and tended to improve DFS (P = 0.064), but not LRFS (P = 0.287) in the middle PORT-I group. PORT could significantly improve OS (P = 0.000), DFS (P = 0.000), and LRFS (P = 0.006) in the high PORT-I group.


CONCLUSIONS
The prediction model is valuable in selecting patients with resected pIIIA-N2 NSCLC fit for PORT. PORT is strongly recommended for patients with three or more of the five factors of smoking index ≤400, cN2, pT3, SCC, and ≥4 positive nodes.
Department of Radiation Oncology, Cancer Institute & Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing, China.
Zhouguang
Z
Hui
Department of Radiation Oncology, Cancer Institute & Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing, China.
Honghai
H
Dai
Department of Radiation Oncology, Cancer Institute & Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing, China.
Jun
J
Liang
Department of Radiation Oncology, Cancer Institute & Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing, China.
Jima
J
Lv
Department of Radiation Oncology, Cancer Institute & Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing, China.
Zongmei
Z
Zhou
Department of Radiation Oncology, Cancer Institute & Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing, China.
Qinfu
Q
Feng
Department of Radiation Oncology, Cancer Institute & Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing, China.
Zefen
Z
Xiao
Department of Radiation Oncology, Cancer Institute & Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing, China.
Dongfu
D
Chen
Department of Radiation Oncology, Cancer Institute & Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing, China.
Hongxing
H
Zhang
Department of Radiation Oncology, Cancer Institute & Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing, China.
Weibo
W
Yin
Department of Radiation Oncology, Cancer Institute & Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing, China.
Luhua
L
Wang
IIIA-N2; non-small-cell lung cancer; postoperative radiotherapy; prediction model; surgery