Objective:This paper will retrospectively analyze the long-term results of PORT for Completely Resected Stage Ⅲa(N2) NSCLC.The strategies of treatment are also to be discussed.Methods:92 cases with Completely Resected Stage Ⅲa(N2)NSCLC treated in our hospital from 1987 to 2004 were analyzed.Among them

46 patients received PORT(Group S+R)

46 no PORT(Group S).39 of the entire patients。received chemotherapy.Median radiation dose was 56 Gy(40～64 Gy).The survival rates were analyzed and compared by Kaplan-Meier and Log-rank.Results:(1)The 5 and 10-year overall survival(OS) for all patients was 44.5% and 30.4%

respectively(.2)The 5 and 10-year OS of group S+R and S was 49.1% vs 36.5% and 36.3% vs 25.4%

respectively

with no significant difference(χ2=0.83

P=0.65)(.3)For the patients with single station involved N2

PORT tends to improve the disease-free survival(DFS) but no reach significant difference.As for patients with multiple stations involved N2

PORT could improve the DFS

the 5 and 10-year DFS of group S+R and S was 40.6% vs.4.5%;21.2% vs.4.1%

respectively

(χ2=4.35

P=0.03)

meanwhile

it might increase the OS(.4) The survival rate treated with PORT from 1996 to 2004 was higher than that from 1987 to 1995

(χ2=4.28

P=0.04)(.5)Recurrence was seen in 63% of patients.The total(both local/regional recurrence and distant metastasis)and local/regional recurrenc rate of group S+R was lower than that of group S

i.e.50.0% vs76.1%(χ2=6.72

P=0.001)and 8.7% vs 32.6%(χ2=8.03

P=0.001)

respectively.Distant metastasis was found to be the main failure cause for both group S+R and S.Multivariate analyses showed that age and number of mediastinal lymph node station involved have influence on the survival of patients with Completely Resected Stage Ⅲa(N2)NSCLC.the DFS.But its value for patients with single station involved N2 was unclear and a further randomized clinical trail is still warrant.(2)Age and the number of mediastinal lymph node station involved are the two significant prognosis factors for patients with Completely Resected Stage Ⅲa(N2)NSCLC(.3)Condition of equipment and radiation technology used could have some influence on the result of PORT(.4)The fact that distant metastasis was the main failure cause for both group S+R and S might imply that patients with Completely Resected Stage Ⅲa(N2)NSCLC might benefit from chemotherapy.It suggests thus that chemotherapy should be considered for these patients.