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Circulating sex hormone levels and colorectal cancer risk in Japanese postmenopausal women: The JPHC nested case–control study
Author(s) -
Mori Nagisa,
Sawada Norie,
Iwasaki Motoki,
Yamaji Taiki,
Goto Atsushi,
Shimazu Taichi,
Inoue Manami,
Murphy Neil,
Gunter Marc J,
Tsugane Shoichiro
Publication year - 2019
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.32431
Subject(s) - medicine , nested case control study , sex hormone binding globulin , odds ratio , colorectal cancer , case control study , testosterone (patch) , cohort study , physiology , endocrinology , oncology , cohort , epidemiology , cancer , hormone , androgen
Previous epidemiological studies evaluated endogenous sex hormone levels and colorectal cancer (CRC) risk have yielded inconsistent results. Also, it is unknown if consumption of dietary isoflavones may influence the endogenous sex hormones and CRC relationships. We conducted a nested case–control study within the JPHC Study Cohort II wherein 11,644 women provided blood samples at the 5‐year follow‐up survey. We selected two matched controls for each case from the cohort (185 CRC cases and 361 controls). Multivariable conditional logistic regression was used to estimate odds ratios (ORs), 95% confidence intervals (CIs) for the association between circulating sex hormone levels and CRC risk. Comparing extreme tertiles, circulating testosterone levels were positively associated with CRC risk (OR = 2.10, 95% CI = 1.11–3.99, p for trend = 0.03). Levels of estradiol, SHBG, and progesterone were not associated with CRC risk. In a subgroup analysis by dietary isoflavone intake, SHBG levels were positively associated with CRC risk among those with low total isoflavone intake ( p for trend = 0.03), with a statistically nonsignificant inverse association among those with high total isoflavone intake ( p for trend = 0.22; p for interaction = 0.002). Endogenous levels of testosterone were positively associated with CRC among postmenopausal women. The association of endogenous SHBG with CRC development may be altered by the level of dietary isoflavone intake.