Urinary total isothiocyanates and colorectal cancer: a prospective study of men in Shanghai, China.
Laboratory and epidemiologic evidence suggests that dietary isothiocyanates (ITCs) may have a chemopreventive effect on cancer. Humans are exposed to ITCs primarily through ingestion of cruciferous vegetables that contain glucosinolates, the precursors to ITCs. The association between urinary total ITC level and colorectal cancer risk was examined in a cohort of 18,244 men in Shanghai, China, with 16 years of follow-up. Urinary total ITCs were quantified on 225 incident cases of colorectal cancer and 1,119 matched controls. Odds ratios (ORs) and their 95% confidence intervals (95% CIs) were calculated using logistic regression models. High levels of urinary total ITCs were associated with a reduced risk of colorectal cancer 5 years after baseline measurements of ITCs, whereas a statistically nonsignificant increase in the risk of colorectal cancer was observed for cases within 5 years of post-enrollment (OR, 1.93; 95% CI, 0.85-4.39 for the upper three quartiles of urinary ITCs versus the lowest quartile). The inverse ITC-colorectal cancer association became stronger with a longer duration of follow-up. Compared with the first quartile, ORs (95% CIs) for the second, third, and fourth quartiles of total ITCs in urine collected 10 or more years before cancer diagnosis were 0.61 (0.35-1.05), 0.51 (0.29-0.92), and 0.46 (0.25-0.83), respectively, for risk of colorectal cancer (P for trend = 0.006). The present study suggests that dietary ITCs may exert tumor inhibitory effects, especially during earlier stages of the multistage process of carcinogenesis.
Moy
Kristin A
KA
The Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, USA.
Yuan
Jian-Min
JM
Chung
Fung-Lung
FL
Van Den Berg
David
D
Wang
Renwei
R
Gao
Yu-Tang
YT
Yu
Mimi C
MC
D016022:Case-Control Studies; D016009:Chi-Square Distribution; D002681:China / Q000453:epidemiology; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000652:urine*; D004032:Diet; D006801:Humans; D015994:Incidence; D017879:Isothiocyanates / Q000652:urine*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D014675:Vegetables
D017879:Isothiocyanates; C037152:isothiocyanic acid