Orignal Articles
Copyright ©2009 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Jun 14, 2009; 15(22): 2708-2713
Published online Jun 14, 2009. doi: 10.3748/wjg.15.2708
Size does not determine the grade of malignancy of early invasive colorectal cancer
Takahisa Matsuda, Yutaka Saito, Takahiro Fujii, Toshio Uraoka, Takeshi Nakajima, Nozomu Kobayashi, Fabian Emura, Akiko Ono, Tadakazu Shimoda, Hiroaki Ikematsu, Kuang-I Fu, Yasushi Sano, Takahiro Fujimori
Takahisa Matsuda, Yutaka Saito, Takahiro Fujii, Toshio Uraoka, Takeshi Nakajima, Nozomu Kobayashi, Fabian Emura, Akiko Ono, Endoscopy Division, National Cancer Center Hospital, Tokyo 104-0045, Japan
Tadakazu Shimoda, Clinical Laboratory Division, National Cancer Center Hospital, Tokyo 104-0045, Japan
Hiroaki Ikematsu, Kuang-I Fu, Yasushi Sano, Division of Digestive Endoscopy and Gastrointestinal Oncology, National Cancer Center Hospital East, Kashiwa 277-8577, Japan
Takahiro Fujimori, Department of Surgical and Molecular Pathology, Dokkyo University School of Medicine, Shimotsuga, Tochigi 321-0293, Japan
Author contributions: Matsuda T, Saito Y and Fujii T contributed equally to this work; Matsuda T, Uraoka T, Nakajima T and Kobayashi N designed the research; Matsuda T, Ikematsu H, Fu KI and Sano Y performed the research; Shimoda T and Fujimori T performed the histopathology; Matsuda T, Saito Y, Emura F and Ono A wrote the paper.
Correspondence to: Takahisa Matsuda, MD, Endoscopy Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan. tamatsud@ncc.go.jp
Telephone: +81-3-35422511
Fax: +81-3-35423815
Received: February 24, 2009
Revised: April 15, 2009
Accepted: April 22, 2009
Published online: June 14, 2009
Abstract

AIM: To clarify the clinicopathological characteristics of small and large early invasive colorectal cancers (EI-CRCs), and to determine whether malignancy grade depends on size.

METHODS: A total of 583 consecutive EI-CRCs treated by endoscopic mucosal resection or surgery at the National Cancer Center Hospital between 1980 and 2004 were enrolled in this study. Lesions were classified into two groups based on size: small (≤ 10 mm) and large (> 10 mm). Clinicopathological features, incidence of lymph node metastasis (LNM) and risk factors for LNM, such as depth of invasion, lymphovascular invasion (LVI) and poorly differentiated adenocarcinoma (PDA) were analyzed in all resected specimens.

RESULTS: There were 120 (21%) small and 463 (79%) large lesions. Histopathological analysis of the small lesion group revealed submucosal deep cancer (sm: ≥ 1000 &mgr;m) in 90 (75%) cases, LVI in 26 (22%) cases, and PDA in 12 (10%) cases. Similarly, the large lesion group exhibited submucosal deep cancer in 380 (82%) cases, LVI in 125 (27%) cases, and PDA in 79 (17%) cases. The rate of LNM was 11.2% and 12.1% in the small and large lesion groups, respectively.

CONCLUSION: Small EI-CRC demonstrated the same aggressiveness and malignant potential as large cancer.

Keywords: Colorectal cancer, Submucosal invasion, Lymph node metastasis, Endoscopic mucosal resection