INTESTINE Vol.16 No.4(1-3)

Theme Small colorectal cancer with high malignant potential
Title Clinicopathological features and treatment strategies for submucosal invasive colorectal cancers
Publish Date 2012/07
Author Takahisa Matsuda Endoscopy Division, National Cancer Center Hospital
Author Taku Sakamoto Endoscopy Division, National Cancer Center Hospital
Author Takeshi Nakajima Endoscopy Division, National Cancer Center Hospital
Author Eriko So Endoscopy Division, National Cancer Center Hospital
Author Masayoshi Yamada Endoscopy Division, National Cancer Center Hospital
Author Hirokazu Taniguchi Pathology Division, National Cancer Center Hospital
Author Ryoji Kushima Pathology Division, National Cancer Center Hospital
Author Takahiro Fujii TF Clinic
Author Yutaka Saito Endoscopy Division, National Cancer Center Hospital
[ Summary ] Early invasive colorectal cancers (EI-CRCs) can be detected even when quite small. However, the grade of malignancy for these small submucosal invasive cancers has not been fully investigated. To clarify the clinicopathological characteristics of EI-CRCs we divided the subjects into two groups, those with smaller or larger lesions. This was done to confirm whether the grade of malignancy depends on size. A total of 1,217 EI-CRC patients treated with EMR or surgery at the NCCH between 1980 and 2011 were enrolled in this study. Lesions were classified into the following two groups based on size for detailed analysis: small (<- 10 mm) and large (> 10 mm). Clinicopathological features, incidence of lymph node metastasis (LNM) and risk factors for LNM such as invasion depth and lymphovascular invasion (LVI) were analyzed in all resected specimens. There were 239 (20 %) and 978 (80 %), small and large lesions respectively. Histopathological analysis of the group with small lesions revealed submucosal (SM) deep cancer (SM: >- 1,000µm) in 172 (72 %) cases and LVI in 59 (25 %) cases. Similarly, the large group exhibited SM deep cancer in 736 (75 %) cases, LVI in 246 (25 %) cases, respectively. Moreover, the rate of LNM was 13.3 % and 11.6 % in small and large groups, respectively. Small EI-CRCs demonstrated the same aggressiveness and malignancy potential as large lesions. Special attention must be paid when treating even small lesions.
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