Association of Poor Differentiation or Positive Vertical Margin with Residual Disease in Patients with Subsequent Colectomy after Complete Macroscopic Endoscopic Resection of Early Colorectal Cancer

Table 1

Clinicopathologic characteristics of patients who underwent colectomy after macroscopic complete endoscopic resection of early colorectal cancer ().

Characteristics	Value
Age, years	60 (31–78)
Men/women	102 (68.9)/46 (31.1)
Tumor location
Cecum and ascending colon	11 (7.4)
Transverse colon	9 (6.1)
Descending colon	6 (4.1)
Sigmoid colon	71 (48.0)
Rectum	51 (34.5)
Size of tumor (histologically measured), mm	13 (4–52)
Macroscopic form of tumor
Pedunculated	32 (21.6)
Semipedunculated	67 (45.3)
Sessile or flat	49 (33.1)
Endoscopic resection method
EMR	141 (95.3)
ESD	7 (4.7)
En bloc resection	121 (81.8)
Histologic differentiation
Well	57 (38.5)
Moderate	84 (56.8)
Poor	3 (2.0)
Mucinous	4 (2.7)
Depth of invasion
Mucosa	4 (2.7)
Submucosa	144 (97.3)
Submucosal invasion depth, μm	2000 (300–7000)
Lymphovascular invasion	30 (20.3)
Positive/unknown vertical endoscopic resection margin	68 (48/20) (45.9)
Positive/unknown lateral endoscopic resection margin	51 (31/20) (34.5)
Reasons for subsequent colectomy
Poorly differentiated/mucinous histology	7 (4.7)
Positive or unknown vertical margin	68 (45.9)
Positive or unknown lateral margin	51 (34.4)
Lymphovascular invasion	30 (20.3)
Submucosal invasion depth >1000 μm	122 (82.4)
Residual tumor in the colorectal wall on colectomy	6 (4.1)
Lymph node metastasis on colectomy	10 (6.8)

EMR: endoscopic mucosal resection; ESD: endoscopic submucosal dissection. Values are median (range) or number (%).