D. T. Nguyen4, C. C. Moodie1, J. R. Garrett1, J. P. Fontaine1,2,3, R. J. Keenan1,2,3, L. A. Robinson1,2,3, E. M. Toloza1,2,3 1Moffitt Cancer Center,Thoracic Oncology,Tampa, FL, USA 2University Of South Florida Morsani College Of Medicine,Surgery,Tampa, FL, USA 3University Of South Florida Morsani College Of Medicine,Oncologic Sciences,Tampa, FL, USA 4University Of South Florida,Morsani College Of Medicine,Tampa, FL, USA
Introduction: Stage-IIIA nonsmall-cell lung cancer (NSCLC) includes T1N2M0 and T2N2M0 in the current Tumor-Nodal-Metastases (TNM) classification, indicating mediastinal lymph node involvement. We evaluated postoperative survival of T1N2/T2N2 patients (pts) who underwent lobectomy without or with radiation therapy (RT) between 1988 and 2013.
Methods: Using the Surveillance, Epidemiology, and End Results (SEER) database, we identified pts who underwent surgery (SURG) without or with RT before (RT+SURG) or after (SURG+RT) surgery for T1N2 and T2N2 NSCLC during 1988-2013. We included pts with Adenocarcinoma (AD) and Squamous Cell (SQ) histology and excluded those with multiple primary NSCLC tumors. Log-rank test was used to compare Kaplan-Meier survival of pts who had SURG vs. SURG+RT as well as of AD vs. SQ pts and of T1N2 vs. T2N2 pts during 1988-2003 and 2004-2013.
Results: Of 2,271 pts, 142 (6.25%) had RT+SURG, 777 (34.2%) had SURG+RT, and 1352 (59.5%) had SURG. During 1988-2013, there were 1681 AD pts (74.0%) and 590 SQ pts (25.9%), while 696 pts were T1N2 (30.6%) and 1,575 pts were T2N2 (69.4%). There was no significant difference in 5-yr survivals between RT and no RT pts or between RT+SURG and SURG+RT during 1988-2013 (p=0.171), in 1988-2003 (p=0.408), or in 2004-2013 (p=0.822). For 1988-2013, AD pts had better 5-yr survival (p=0.016) and median survival time (MST; 36.0±1.4 mon vs. 27.0±1.6 mon; p<0.01) than SQ pts. For 1988-2003, 5-yr survival for AD pts and SQ pts did not differ (p=0.181). However, for 2004-2013, AD pts had better 5-yr survival (36.0% vs. 31.6%; p<0.01) and MST (41.0±2.1 mon vs. 27.0±2.2 mon; p<0.01) than SQ pts. As expected, T1N2 had better 5-yr survival than T2N2 during 1988-2013 (39.1% vs. 29.8%; p<0.01), during 1988-2003 (34.7% vs. 25.7%; p=0.002), and during 2004-2013 (41.5% vs. 31.9%; p<0.01). Similarly, AD pts had better MST than SQ pts for 1988-2013 (44.0±3.2 mon vs. 30.0±1.2 mon; p<0.001), for 1988-2003 (41.0±3.6 mon vs. 26.0±1.1 mon; p<0.01), and for 2004-2013 (47.0±4.2 mon vs. 33.0±1.8 mon; p<0.01). With AD T1N2, AD T2N2, SQ T1N2, or SQ T2N2 pts, we found no differences in 5-yr survival between RT+SURG vs. SURG+RT (p>0.05).
Conclusion: Pts with RT+SURG or SURG+RT did not have better survival than SURG alone in T1N2 and T2N2 pts. Of these pts, AD pts had better survival than SQ pts during 1988-2013, but this advantage was due to improved survival during 2004-2013. As expected, T1N2 pts had better survival than T2N2 pts across all time periods.
