Transverse mesocolon invasion in advanced gastric cancer: should we reconsider current T staging?

BACKGROUND

According to the AJCC/UICC TNM classification, T mesocolon invasion in AGC is classified as T2b or T3 according to the presence or the absence of serosa invasion. However, many authors have considered T mesocolon invasion in AGC as T4. This study was performed to evaluate the appropriate T stage for T mesocolon invasion in AGC.

MATERIALS AND METHODS

From 1996 to 2008, 90 patients underwent curative gastrectomy with T mesocolon excision at the authors' institute under the suspicion of T mesocolon invasion based on surgical findings and without pathologic invasion to any other organ. Histopathologic findings were reviewed to determine whether tumors had invaded the T mesocolon. Survival data of AGC patients registered in the SNUH database (N = 9998, from 1986 to 2007) was used as reference data for comparative purposes.

RESULTS

A total of 27 patients (30%) had proven histopathological invasion of the T mesocolon, and a significant difference in survival rates was found between these 27 and the remaining 63 (P = .012). As compared with the SNUH database population, the survival rate of T mesocolon invasion patients differed from those of T2b (P < .001) and T3 (P = .043) patients, but was similar to that of T4 patients (P = .218). Furthermore, for N1 stage patients, the survival rate differed from those of T2b (P = .001) and T3 (P = .046) patients, but was similar to that of T4 patients (P = .744).

CONCLUSIONS

The T stage of T mesocolon invasion in AGC should be revised to AJCC/UICC stage T4, because the survival rate of T mesocolon invasion AGC is lower than that of stage T2b or T3.