Colorectal polypectomy and risk of colorectal cancer by subsite: the Fukuoka Colorectal Cancer study.
BACKGROUND
Colorectal adenomas are well-established precursor lesions for colorectal cancer and removal of polyps is deemed to reduce the risk of colorectal cancer. However, benefit of colorectal polypectomy in routine practice is still uncertain. We therefore investigated subsite-specific risks of colorectal cancer in relation to history of colorectal polypectomy in a case-control study.


METHODS
Both case patients and control subjects were residents aged 20-74 years in Fukuoka City and three adjacent areas. The case group comprised 840 patients undergoing surgery for a first diagnosis of colorectal cancer, while the control subjects were 833 residents who were selected in the community by two-stage random sampling. Past history of selected diseases, surgery and lifestyle factors were ascertained by in-person interview. Statistical adjustment was made for sex, 5-year age class, residence, smoking, alcohol drinking, physical activity, body mass index and parental history of colorectal cancer.


RESULTS
Overall, 74 case patients (9%) and 85 control subjects (10%) reported a prior history of colorectal polyps, and 50 cases (6%) and 64 controls (8%) had a history of colorectal polypectomy. The adjusted odds ratio associated with colorectal polypectomy was 0.71 (95% confidence interval [CI] 0.48-1.06) for the overall risk of colorectal cancer. The corresponding values for cancer of the proximal colon, distal colon, and rectum were 1.68 (95% CI 0.98-2.88), 0.71 (95% CI 0.41-1.26) and 0.24 (95% CI 0.11-0.52), respectively.


CONCLUSIONS
The findings indicate that colorectal polypectomy in current practice confers a decreased risk of rectal cancer and possibly of distal colon cancer.
Yoshida
Daigo
D
Department of Preventive Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. dyoshida@phealth.med.kyushu-u.ac.jp
Kono
Suminori
S
Moore
Malcolm A
MA
Toyomura
Kengo
K
Nagano
Jun
J
Mizoue
Tetsuya
T
Mibu
Ryuichi
R
Tanaka
Masao
M
Kakeji
Yoshihiro
Y
Maehara
Yoshihiko
Y
Okamura
Takeshi
T
Ikejiri
Koji
K
Futami
Kitaroh
K
Yasunami
Yohichi
Y
Maekawa
Takafumi
T
Takenaka
Kenji
K
Ichimiya
Hitoshi
H
Imaizumi
Nobutoshi
N
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003111:Colonic Polyps / Q000601:surgery*; D015179:Colorectal Neoplasms / Q000209:etiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D007417:Intestinal Polyps / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012002:Rectal Diseases / Q000601:surgery*