Body mass index, body height, and subsequent risk of colorectal cancer in middle-aged and elderly Japanese men and women: Japan public health center-based prospective study.
OBJECTIVE
To investigate the association of body mass index (BMI) or body height with colorectal cancer incidence in a population-based prospective study.


METHODS
We identified 986 (626 men and 360 women) newly diagnosed cases of colorectal cancer during the 9.4-year follow-up of a cohort consisting of 102,949 (49,158 male and 53,791 female) middle-aged and elderly Japanese.


RESULTS
Lower BMI groups (lower than 23) were not associated with colorectal cancer compared with the 23-24.9 BMI group. Any categories of 25-26.9, 27-29.9, or 30 or more BMI were associated with an increased risk of colorectal cancer compared with the lower than 25 BMI (RR, 1.2 for 25-26.9, 1.4 for 27-29.9, and 1.5 for 30 or more; p for trend, 0.004) in men. These associations were more evident only in invasive-type cancer analysis. BMI was not associated with the risk of colorectal cancer in women. No significant association with height was obtained for either men or women.


CONCLUSIONS
The association of BMI with colorectal cancer was confirmed in a Japanese population as well as Western populations. Only invasive-cancer analysis suggested that BMI was important for tumor growth and proliferation. Approximately 6.7% of colorectal cancer was attributable to a BMI of 25 or higher in middle-aged and elderly Japanese men.
Otani
Tetsuya
T
Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan. teotani@gan2.res.ncc.go.jp
Iwasaki
Motoki
M
Inoue
Manami
M
D000328:Adult; D000367:Age Factors; D000368:Aged; D001827:Body Height; D015992:Body Mass Index; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D011159:Population Surveillance; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors