New Nodal Classification Discriminates Better Survival Time Than That of the 7th AJCC Cancer Staging in Patients with Small Intestinal Adenocarcinoma (SIAC): An Analysis with the SEER Database
Ho-Seop Park, Daewoo Pak, Hyo Jeong Kang, Eunsil Yu, HyungJun Cho, Seung-Mo Hong. University of Ulsan College of Medicine Asan Medical Center, Seoul, Korea; Korea University, Seoul, Korea
Background: The lymph node (LN) classification of the 7th edition of the AJCC cancer staging of SIAC divided the previous N1 (LN metastasis) into the new N1 (1-3 LNs metastasis) and N2 (>4 LNs metastasis) without providing any information for changes.
Design: From the SEER database, 3,199 surgically resected SIACs were evaluated. To identify optimal cut-off points for N classification, recursive partitioning technique was coupled with the log-rank test.
Results: All cases were classified as 3 groups (G1, no LN metastasis; G2, 1-2 LNs metastasis; G3, >3 LNs metastasis) with the optimal cut-off points of 0 (p<0.0001) and 2 (p<0.0001). The survival difference among 3 groups (p<0.0001) and multiple comparisons for the log-rank test of each group (G1 and G2, p<0.0001; G2 and G3, p<0.0001) were statistically significant. By 7th edition of the AJCC cancer staging, a significant survival difference was also observed among 3N classifications comparison (p<0.0001) and between N0 and N1 (p<0.0001). but no significant survival difference was observed between N1 and N2 (p=0.84).
Conclusions: New grouping of LN classification showed better discrimination of survival time in SIAC patients than the current LN classification. Therefore, we propose that the current LN classification of SIAC should be changed into N0 (no LN metastasis), N1 (1-2 LNs metastasis), and N2 (>3 LNs metastasis).
Monday, March 4, 2013 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 109, Monday Morning