Use of GEWF Solution in the Gross Examination of Colorectal Adenocarcinoma Resection Specimens Is Associated with Increased Lymph Node Yield but Not Improved Survival
Hector H Li Chang, Ken Newell, David K Driman. University of Western Ontario, London, ON, Canada; Grey Bruce Health Services, Owen Sound, ON, Canada
Background: The number of lymph nodes identified in colorectal adenocarcinoma (CRC) resection specimens correlates positively with clinical outcomes. The identification of a greater number of lymph nodes increases the likelihood of appropriate staging, and the identification of 12 lymph nodes is a key quality measure for colon cancer care. Rectal resections and some colon resections may be associated with suboptimal lymph node yields (LNY). GEWF solution (glacial acetic acid, ethanol, water, formalin) is a safe, simple, and inexpensive lymph node highlighting (not fat-clearing) solution that has been demonstrated to result in significantly improved lymph node retrieval. Whether its use is associated with improved clinical outcomes has not been studied.
Design: Patients with stage I-III CRC who underwent primary surgical resection at two partner institutions were selected sequentially from 2002-2004; an a priori power analysis was performed to determine an adequate sample size for detecting survival benefit. GEWF solution was routinely used for lymph node retrieval in the study group and not in the control group. Clinical and pathologic features including LNY, disease-free survival (DFS), and overall survival (OS) were compared.
Results: One hundred fifty-three resections were examined using GEWF solution, and 169 resections were examined without GEWF. Use of GEWF solution was associated with significantly greater LNY (21.0 ± 10.1 vs. 13.2 ± 7.2, P < 0.0001) and a greater number of positive lymph nodes (1.7 ± 3.5 vs. 1.1 ± 2.2, P < 0.05). Twelve or more lymph nodes were more frequently identified in specimens examined with GEWF (82.4% vs. 50.0%, P < 0.0001). Use of GEWF was more often associated with adequate LNY in rectal specimens (80.0% vs. 37.9%, P < 0.05) and specimens measuring ≤ 15 cm in length (68.9% vs. 48.4%, P < 0.05). No differences in DFS or OS were noted between the two groups (mean follow-up = 63.2 ± 27.7 months). The two groups were otherwise similar with respect to patient and tumor characteristics.
Conclusions: Use of GEWF solution in the gross examination of CRC specimens is associated with improved LNY and a larger number of positive nodes. Although routine use of GEWF does not lead to improved patient outcomes, laboratory quality measures may be more readily achieved with its use, particularly when assessing problematic specimens.
Category: Quality Assurance
Monday, March 19, 2012 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 306, Monday Morning