ressElmer Small, Depressed-Type Early Colon Cancer Invading Shallow Submucosal Layer With Extensive Lymph Node

Early colorectal cancers are defined as invasive tumors that are lim-ited to the mucosal layer or submucosal layer (SM), regardless of the presence or absence of lymph node (LN) metastasis. The report-ed incidence of LN metastasis of SM1 colon cancers is 0- 5.9%, but the incidence in SM2 and SM3 colon cancers could be as high as 11.3- 25.0%, and risk factors for LN metastasis include depth of SM invasion, growth patterns (polypoid or non-polypoid), his-tological sub-classification (moderate or poor differentiation) and regional lymphatic and vascular invasion. Among colorectal can-cers with non-polypoid growth, the malignant potential is higher for depressed, than polypoid types, even for small tumors. Herein, we describe a patient with small, depressed-type early colon cancer with extensive LN metastasis and superficial SM invasion (pSM 450 μm). Six courses of chemotherapy with mFOLFOX6 and be-vacizumab reduced the size of the LN metastases, thus eliciting a partial response (PR) according to the response evaluation criteria in solid tumors (RECIST)