Published online Aug 7, 2016. doi: 10.3748/wjg.v22.i29.6726
Peer-review started: March 25, 2016
First decision: May 12, 2016
Revised: May 25, 2016
Accepted: June 15, 2016
Article in press: June 15, 2016
Published online: August 7, 2016
Processing time: 127 Days and 6.1 Hours
AIM: To hypothesize that in patients with colon cancer showing heavy intestinal wall invasion without distant metastasis (T4bN0-2M0), small tumor size would correlate with more aggressive tumor behaviors and therefore poorer cancer-specific survival (CSS).
METHODS: We analyzed T4bN0-2M0 colon cancer patients in the Surveillance, Epidemiology and End Results (SEER) database. A preliminary analysis of T4bN0-2M0 colon cancer patients at the Fudan University Shanghai Cancer Center is also presented.
RESULTS: A total of 1734 T4bN0-2M0 colon cancer patients from the SEER database were included. Kaplan-Meier analysis revealed decreasing CSS with decreasing tumor size (P < 0.001). Subgroup analysis showed a significant association between poorer CSS with smaller tumor size in T4bN0 patients (P = 0.024), and a trend of association in T4bN1 (P = 0.182) and T4bN2 patients (P = 0.191). Multivariate analysis identified tumor size as an independent prognostic factor for CSS in T4bN0-2M0 patients (P = 0.024). Preliminary analysis of Fudan University Shanghai Cancer Center samples suggested the 5-year CSS was 50.0%, 72.9% and 77.1% in patients with tumors ≤ 4.0 cm, 4.0-7.0 cm and ≥ 7.0 cm.
CONCLUSION: Smaller tumor size is associated with poorer CSS in the T4bN0-2M0 subset of colon cancer, particularly in the T4bN0M0 subgroup.
Core tip: In contrast to the association of larger tumor size with poor cancer-specific survival (CSS) in colon cancer patients overall, this study suggested that smaller tumor size was associated with poor CSS in the T4bN0-2M0 subpopulation, particularly in the T4bN0M0 subgroup.