Efifcacy And Prognosis Of Postoperative Adjuvant Radiotherapy In Completely Resected IIIA (N2) Non-small Cell Lung Cancer

Objective：To investigate the therapeutic effect and prognosis of postoperativeadjuvant radiotherapy in completely resected IIIA(N2) non-small cell lung cancer．Methods：We retrospectively analyzed64patients treated at the First AffiliatedHospital of Dalian Medical University between Jan2006and Jan2011with completelyresected IIIA(N2) non-small cell lung cancer．35patients underwent postoperativeadjuvant radiotherapy (PORT group) and29patients did not receive PORT (not receivepostoperative radiotherapy，no-PORT group)．All patients underwent four cyclesplatinum-based adjuvant chemotherapy after operation．The chemotherapy regimensincluded NP(vinorelbine and cisplatin)，GP(gemcitabine and cisplatin)，TP(docetaxeland cisplatin)，PP(pemetrexed and cisplatin)．The PORT group patients were treatedwith three-dimensional conformal radiotherapy after adjuvant chemotherapy．Themedian radiation dose was50Gy．The no-PORT group patients were observation afteradjuvant chemotherapy．The median follow-up time was29months．The two groupswere compared in terms of overall survival (OS) rate，local recurrence-free survival(LRFS) rate，distant recurrence-free survival (DRFS) rate，disease-free survival (DFS)rate，and radiotherapy side effects．The Kaplan-Meier method was used for calculatingOS rate，LRFS rate，DRFS rate and DFS rates，and the differences between the twogroups were analyzed by log-rank test．Univariate was also adopted Kaplan-Meiermethod to evaluate the effect of each specific parameter．Multivariate Cox regressionmodels including all evaluated parameters were performed to identify the majorsignificant prognostic factors．Results： 1．The median OS was32months in PORT group and28months in no-PORTgroup， The1-year，2-year，3-year overall survival rate was91.4%，74.3%，48.5%inPORT group and85.7%，67.9%，34.6%in no-PORT，there was a statistical difference（P=0.048）．2．The median LRFS was24months in PORT group and16months in no-PORTgroup，The1-year，2-year，3-year local recurrence-free survival rate was74.3%，54.3%，42.9%in PORT group and60.7%，35.7%，28.6%in no-PORT，there was a statisticaldifference（P=0.045）．3．The3-year distant recurrence-free survival was40.2%in PORT group and40.8%in no-PORT（P=0.857），there was no statistical difference．The3-yeardisease-free survival was30.8%in PORT group and17.9%in no-PORT（P=0.047），there was a statistical difference．4．In univariate analysis，weight，histology type，tumor differentiation degree andpostoperative adjuvant radiotherapy were significant factor for OS．Weight， histologytype，tumor differentiation degree and postoperative adjuvant radiotherapy weresignificant factor for LRFS．In multivariate analysis，histology type and postoperativeadjuvant radiotherapy were independent prognostic factor for OS．Histology type，postoperative adjuvant radiotherapy were independent prognostic factor for LRFS．5．The major radiotherapy side effects were radiation esophagitis and bone marrowdepression，incidence rate was37.2%and14.3%，respectively．Conclusion：1． PORT may improve LRFS and OS in completely resected IIIA(N2)non-small cell lung cancer．2．PORT may improve DFS，but there was no impact on DRFS．3．Histology type and postoperative adjuvant radiotherapy were independentprognostic factor for OS and LRFS． Non-squamous cell carcinoma with poorprognosis．4．The major radiotherapy side effects were radiation esophagitis and bone marrowdepression，patients with an acceptable treatment-related toxicity．...