Frequency of coexistent carcinoma in sessile serrated adenoma/polyps and traditional serrated adenomas removed by endoscopic resection.
OBJECTIVE
Sessile serrated adenoma/polyps (SSA/Ps) have a different potential than traditional adenomatous polyps for developing into malignant colorectal cancer. However, little is known about the coexistent cancer rate. Here, we evaluate the frequency of carcinoma in serrated polyps removed by endoscopic resection (ER).


METHODS
This was a retrospective single-center cohort study of consecutive patients with colorectal polyps who underwent ER from March 2003 to October 2014. We determined the frequency of serrated polyps among all resected colorectal polyps and analyzed the clinicopathological findings as well as the frequency and characteristics of coexistent carcinoma in the serrated polyps resected by ER based on pathology reports.


RESULTS
A total of 21,048 polyps from 15,326 patients were identified, including 15,984 traditional adenomatous polyps (75.9 %), 621 SSA/Ps (3.0 %), 136 traditional serrated adenomas (TSAs) (0.6 %), 1,121 hyperplastic polyps (5.3 %), and 3,186 polyps of other types (15.1 %). The clinical and endoscopic findings of SSA/Ps revealed a male predominance (68.6 %), with 61.7 % of the polyps located in the proximal colon. Males accounted for 77.2 % of all patients with TSAs, and 77.2 % of these polyps were located in the distal colon. The mean sizes of the SSA/Ps and TSAs were 8.8 and 10.7 mm, respectively. Among the SSA/Ps, 8 (1.3 %) cases had coexistent carcinoma, and 1 (0.7 %) patient with TSA showed coexistent carcinoma. In the patients with SSA/Ps, female sex and a tumor size ≥ 10 mm were predictive factors for coexistent carcinoma.


CONCLUSIONS
The frequency of SSA/Ps with carcinoma was lower than that for traditional adenoma. Female sex and tumor size ≥ 10 mm were significant predictive factors for coexistent carcinoma.
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Hirotsugu
H
Saiki
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Tsutomu
T
Nishida
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Masashi
M
Yamamoto
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Shiro
S
Hayashi
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Hiromi
H
Shimakoshi
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Akiyoshi
A
Shimoda
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Takahiro
T
Amano
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Aisa
A
Sakamoto
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Yuriko
Y
Otake
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Aya
A
Sugimoto
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Kei
K
Takahashi
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Kaori
K
Mukai
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Tokuhiro
T
Matsubara
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Sachiko
S
Nakajima
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Koji
K
Fukui
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan.
Masami
M
Inada
Department of Gastroenterology, Toyonaka Municipal Hospital, Osaka, Japan; Department of Gastroenterology, Japan Community Healthcare Organization, Osaka Hospital, Osaka, Japan.
Katsumi
K
Yamamoto
Department of Pathology, Toyonaka Municipal Hospital, Osaka, Japan.
Ryozo
R
Tokuda
Department of Pathology, Toyonaka Municipal Hospital, Osaka, Japan.
Shiro
S
Adachi