Survival Analysis Of Patients With/Without Lymph Node Examination After Lung Cancer Resection

7054 Background: Lymph node (LN) stage is the major prognostic factor in resectable lung cancer. Yet 16-18% of U.S. lung cancer resections have no examined LN (pNx). These patients are usually treated as though they were node negative, potentially misstating their true stage, prognosis, and benefit from adjuvant therapy. We compared the survival of patients in a Memphis cohort who had pNx to those without metastatic LN after examination of at least 1 LN (pN0). Methods: Retrospective review of all surgical resections in Memphis, TN, from 2004 to 2009, excluding patients with pre-operative therapy. Standard statistical methods were used for group comparisons. Results: Of 872 eligible patients, 12% were pNx. Group characteristics are compared in the table. Only 15% of the pN0 group had more than 10 LN examined. 5-year survival rates (pN0 v pNx) were: 56% v 41% (whole group); 64% v 47% (T1); 53% v 0% (T2); (p<0.05 for all comparisons). In multivariate analysis adjusting for type of resection, histology, and T category, pNx had a hazard ratio for death of 1.6 (confidence interval 1.1-2.3, p<0.02). Conclusions: After lung cancer resection, patients without LN examination have inferior long-term survival. A significant proportion probably have undiagnosed LN metastasis, because the surgeon did not remove involved hilar/mediastinal LN or the pathologist did not examine hilar/intrapulmonary nodes. Improvements in surgical LN harvesting and pathology examination practice are needed to eliminate this problem. Variable, N (%) pN0, N=771 pNx, N=101 P value Age, median (range) 68 (19-89) 70 (37-86) >0.05 Sex Female 332 (43) 51 (51) 0.16 Male 439 (57) 50 (50) Race Black 185 (24) 20 (20) 0.47 White 580 (75) 80 (79) Other 6 (1) 1 (1) Type of resection Pneumonectomy 51 (7) 0 (0) <0.0001 Lobe/bilobectomy 663 (86) 42 (42) Sublobar 57 (7) 59 (59) Histology Adeno 356 (46) 50 (50) 0.38 Squamous 332 (43) 36 (36) Other 83 (11) 14 (14) T Category 1 370 (48) 70 (69) 0.0007 2 278 (36) 21 (21) 3 96 (12) 7 (7) 4 25 (3) 2 (2) Median (range) tumor size, cm 2.5 (0.2-21) 2.0 (0.6-8) <0.0001 # LN examined, median (range) N1 3 (0-38) N2 2 (0-29) total 5 (1-45) Hazard ratio for death (CI) T1 1.0 1.7 (1.1, 2.5) 0.01 T2 2.0 (1.0, 3.8) 0.04 30-day mortality, % 4 4 0.99