D. T. Nguyen4, J. P. Fontaine1,2,3, L. A. Robinson1,2,3, R. J. Keenan1,2,3, 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: Non-small cell lung cancer (NSCLC) is staged using Tumor-Node-Metastasis(TNM) status. Tumor histology is graded based on being well differentiated (Grade1), moderately differentiated (Grade2), or poorly differentiated (Grade3). We investigated effects of histologic grade on survival of patients (pts) with stage-I neuroendocrine tumors after surgical resection.
Methods: Using the Surveillance, Epidemiology, and End Results (SEER) database, we identified pts who underwent lobectomy for stage-I (T1N0M0 or T2N0M0) neuroendocrine carcinoma during 1988-2013, but excluded those who had multiple primary NSCLC tumors. We grouped pts by histologic grade and performed Kaplan-Meier survival analyses, with log-rank test to compare 5-yr cancer-specific survival between grades, between T status, and between 1988-2003 versus 2004-2013.
Results: Of 515 study pts, 348 were T1N0 pts, of whom 200 were Grade1, 52 were Grade2, and 96 were Grade3, and 167 were T2N0 pts, of whom 53 were Grade1, 31 were Grade2, and 83 were Grade3. During 1988-2013, T1N0 Grade3 pts had worse 5-yr survival than either T1N0 Grade2 or Grade1 pts (52.6% vs. 82.8% or 97.6%; p<0.001) and worse mean survival time (MST) than either T1N0 Grade2 or Grade1 pts (42.8 mon vs. 56.2 mon or 59.4 mon, p<0.05). In contrast, both T2N0 Grade3 and Grade2 pts had worse 5-yr survival than T2N0 Grade1 pts (54.0% or 68.4% vs. 93.6%; p=0.001) and MST (41.2 mon or 47.9 mon vs. 56.8 mon, p<0.05). For all Grade2 pts during 1988-2013, T2N0 pts had worse 5-yr survival than T1N0 pts (68.4% vs. 82.8%; p=0.07 by Log Rank Mantel-Cox, but p=0.038 by Breslow-Wilcoxon and p=0.047 by Tarone-Ware) and worse MST than T1N0 pts (47.9 mon vs. 56.2 mon, p<0.05). In contrast, for all Grade3 pts, T1N0 and T2N0 pts had similar 5-yr survival (52.6% vs 54.0%; p>0.53) and MST (41.2 mon vs. 42.8 mon, p>0.05) during 1988-2013. Neither Grade2 T1N0 or T2N0 nor Grade3 T1N0 or T2N0 had 5-yr survival or MST that significantly changed between 1988-2003 versus 2004-2013 (p>0.05).
Conclusion: Using SEER data, we found that histologic grade significantly affected survival of stage-I neuroendocrine carcinoma pts after pulmonary lobectomy, with Grade3 pts having significantly worst survival than Grade2 or Grade1 for both T1N0 and T2N0 pts, but with Grade2 pts having worse survival than Grade1 only for T2N0 pts. These results suggest that histologic grade should be considered when determining adjuvant therapy and prognosis for surgically resected stage-I neuroendocrine carcinoma pts.
