Micrometastasis Volume in Lymph Nodes Determines Disease Recurrence Rate of Stage II Colorectal Cancer: A Prospective
Hirofumi Yamamoto1, Kohei Murata2, Mutsumi Fukunaga3
1Department of Surgery, Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan. Department of Molecular Pathology, Division of Health Sciences, Graduate School of Medicine, Osaka University, Osaka, Japan. hyamamoto@gesurg.med.osaka-u.ac.jp.
Purpose:
We reported in a retrospective study that the presence of micrometastasis in lymph nodes, when assessed by carcinoembryonic antigen (CEA)-specific RT-PCR, is a significant prognostic factor in stage II colorectal cancer. The aim of this study was to clarify the clinical value of micrometastasis in a prospective multicenter trial.
Experimental Design:
From November 2001 to December 2005, a total of 419 colorectal cancer cases were preoperatively registered at a central data center. Of them, 315 node-negative stage II colorectal cancer cases were enrolled. After RNA quality check, 304 colorectal cancer cases were analyzed for CEA mRNA in lymph nodes by both conventional RT-PCR (a band method) and quantitative RT-PCR. Long-term prognosis of the patients was determined by each method.
Results:
A positive band for CEA mRNA was detected in 73 (24.0%) of 304 patients. Postoperative adjuvant chemotherapy was applied in 31 CEA band-positive cases with an oral 5-fluorouracil derivative HCFU (1-hexylcarbamoyl-5-fluorouracil) for 1 year, whereas chemotherapy was not administered to CEA band-negative group. Multivariate Cox regression analyses revealed that a high micrometastasis volume (high MMV, n = 95) was an independent poor prognostic factor for 5-year disease-free survival (DFS; P = 0.001) and 5-year overall survival (OS; P = 0.016).
Conclusions:
This prospective clinical trial demonstrates that micrometastasis volume is a useful marker in identifying patients who are at high or low risk for recurrence of stage II colorectal cancer. Clin Cancer Res; 22(13); 3201-8. ©2016 AACR.
