Significant Operator Dependent Grossing Differences in Lymph Node Sampling from Esophageal Cancer Resections
Eugene Carneal, Terry Morgan, James Dolan, John Hunter, Ken Gatter. Oregon Health and Science University, Portland, OR
Background: It is currently unclear whether aggressive lymph node dissection improves patient survival after esophageal cancer surgery. Recent recommendations include minimum numbers of lymph nodes, both to ensure adequate staging and perhaps reflect adequate surgical treatment. Our objective was to identify potential sources of operator variance by personnel grossing esophageal cancer resections performed at our institution.
Design: We conducted a single center retrospective review of 178 patients with esophageal cancer treated by esophagectomy with and without neoadjuvant therapy between July 2000 and July 2011. The total number of dissected lymph nodes obtained by pathology assistants (PA), medical student fellows, and pathology residents (PGY1-4) were recorded for each academic year (July 1 through June 30). Preliminary trend analysis suggested potential differences between PA and non-PA personnel. Nonparametric statistics using the Mann-Whitney U-test were performed to evaluate for significance.
Results: Lymph node harvesting was relatively constant from 2000-2003 with a sharp upward trend starting in 2004 (fig 1). From 2004-2011, 148 esophagectomies were grossed revealing a divergence between PA (n=43) and those grossed by residents and pathology medical student fellows (non-PA, n=103) (fig 2). During this interval PAs recovered significantly more lymph nodes per specimen (mean=20.5) compared with non-PAs (mean=15.8) (Mann-Whitney U test p-value=0.0193).
Conclusions: The upward trend after 2004 may be due to a greater awareness of the significance of lymph node number by the pathology staff. Since more lymph nodes were recovered by PAs compared with non-PAs, we conclude that training and experience are important variables in total number of nodes submitted for microscopic examination and diagnosis. Future studies and recommendations about the biologic importance of total number of lymph nodes recovered should account for this variable.
Tuesday, March 20, 2012 1:00 PM
Poster Session IV # 56, Tuesday Afternoon