Clinicopathological analyses of advanced colorectal cancers of different sizes--especially those of 20 mm or less in diameter.
OBJECTIVE
Many small cancers of the flat type can now be detected, and many advanced cancers of the flat type have been discovered. In this study, to clarify the clinicopathological characteristics of small advanced cancers, advanced cancers of 20 mm or less in diameter were compared with those of other sizes.


METHODS
Patients with advanced colorectal cancer (n = 865) were divided into four groups on the basis of cancer diameter as follows: Group A (20 mm or less), 21 patients; Group B (21-60 mm), 581 patients; Group C (61-100 mm), 215 patients; and Group D (101 mm or more), 48 patients. These groups were compared for various clinicopathological findings.


RESULTS
The depth of invasion was muscularis propria in 14 cases and subserosa in 7 cases. In Group A, cancer was histologically well-differentiated in 8 cases, moderately differentiated in 12 cases, and mucinous in one case. Six cases (28.6%) in Group A had lymph node metastasis (N1). In Group A, one patient had multiple liver metastasis and all of the other cases were assessed as R0 resection.


CONCLUSIONS
Most small advanced colorectal cancers of 20 mm or less in diameter can be regarded as quasi-early cancers, but some have the potential for high malignancy, and for these, reduction surgery cannot be used.
Kasakura
Y
Y
Third Department of Surgery, Nihon University School of Medicine, 30-1 Oyaguchi-kamimachi, Itabashi-ku, Tokyo 173-8610, Japan. yuichik@med.nihon-u.ac.jp
Fujii
M
M
Mochizuki
F
F
Kobayashi
M
M
Yamagata
M
M
D002288:Adenocarcinoma, Mucinous / Q000401:mortality / Q000473:pathology*; D003106:Colon / Q000473:pathology; D015179:Colorectal Neoplasms / Q000401:mortality / Q000473:pathology*; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000401:mortality / Q000473:pathology*; D006801:Humans; D008207:Lymphatic Metastasis; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D009360:Neoplastic Cells, Circulating; D011379:Prognosis; D015996:Survival Rate