Clinical significance of small colorectal adenoma less than 10 mm: the KASID study.
OBJECTIVE
Polypectomy is the current modality of choice to prevent benign colorectal adenoma from progressing to an invasive cancer. However, in cases of small colorectal adenoma, it remains unclear as to whether polypectomy is actually an effective treatment modality. We evaluated the clinical significance of polypectomy in cases of small colorectal adenomas, measuring less than 10 mm.


METHODS
All colonoscopies were performed at 11 Korean tertiary medical centers, between July 2003 and March 2004. A total of 5996 colorectal adenomas were detected and divided into 5 groups according to their size (Group 1; 1-5 mm, Group 2; 6-7 mm, Group 3; 8-9 mm, Group 4; 10-19 mm, Group 5; more than 20 mm). The term 'advanced adenoma' refers here to tubular adenomas with diameters of at least 10 mm, or to tubulovillous, villous, or high-grade dysplasia, irrespective of size. 'Cancer' here is defined as the invasion of malignant cells beyond the muscularis mucosa.


RESULTS
As the sizes of the adenomas increased, the prevalence of advanced adenoma was also observed to increase. In Groups 2 and 3, the prevalence of tubulovillous or villous adenoma were higher than was expected (5.2% and 6.6%, p < 0.001). Interestingly enough, in Group 2, the prevalence of cancer was at least as high as in Group 4 (0.7% vs. 0.5%, p < 0.001).


CONCLUSIONS
In cases of small colorectal adenomas, measuring between 6 and 9 mm, the prevalence of cancer was at least as high as that seen in the cases of colorectal adenomas measuring between 10 and 19 mm. Therefore, small colorectal adenomas measuring between 6 and 9 mm should not be ignored, in order to decrease the prevalence of colorectal cancer.
Yoo
Tae Woo
TW
Department of Internal Medicine, Kangbuk Samsung Hospital, Korea.
Park
Dong Il
DI
Kim
Young-Ho
YH
Kim
Hyun Soo
HS
Kim
Won Ho
WH
Kim
Tae Il
TI
Kim
Hyo Jong
HJ
Yang
Suk-Kyun
SK
Byeon
Jeong-Sik
JS
Lee
Moon Sung
MS
Jung
Il Kwon
IK
Chung
Moon Kwan
MK
Jung
Sung-Ae
SA
Jeen
Yoon Tae
YT
Choi
Jai Hyun
JH
Choi
Hwang
H
Han
Dong Soo
DS
Song
Jae Suk
JS
D018253:Adenoma, Villous / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D018256:Adenomatous Polyps / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D015331:Cohort Studies; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011230:Precancerous Conditions / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D012307:Risk Factors