Lymph Node Sampling Rates and Wedge Resection for Primary NSCLC: An Analysis of the SEER Database (2004-2012)
Cameron T. Stock, Jr., Karl Uy, Maggie Powers, Geoffrey Graeber. UMass Memorial Medical Center, Worcester, MA USA.
Objective: Low rates of lymph node (LN) sampling in patients undergoing non-anatomic sub-lobar resections for NSCLC compared with lobectomty have been reported. LN status plays a role in determining which patients receive adjuvant therapy following resection. Given the interest in LN sampling for staging and adjuvant treatment, the SEER database from 2004-2012 was analyzed to determine if the rates of LN sampling have changed over time.
Methods: The SEER database was queried from 2004-2012. All patients who underwent wedge resections for NSLC during this time were included. Overall, 5135 patients were included in the analysis. Patients were excluded if the number of lymph nodes sampled was reported as unknown at the time of surgery.
Results: Overall, 47.7% had no lymph nodes sampled (-nodal sampling). When analyzed over time, from 2004-2007 50.1% of patients -nodal sampling, 2008-2010 48.3% of patients -nodal sampling, from 2011-2012 43.1% of patients -nodal sampling. When matched for T stage (T1a) from 2010-2012 the overall survival was 92.4% in patients + nodal sampling vs. 87% in patients -nodal sampling. The cancer specific survival was 96.2% +nodal sampling vs. 92.6% -nodal sampling. 6% of patients with T1a lung cancer had positive nodes when pathologically staged.
Conclusions: The percentage of patients who fail to have LN sampling performed when undergoing wedge resection has decreased over time. However, as of 2012 over 40% of patients did not have LN sampled. In patients with T1a lesions, LN sampling correlates with increased survival possibly due to improved staging.