Endogenous sex hormones and colorectal cancer survival among men and women.

Although previous studies have suggested a potential role of sex hormones in the etiology of colorectal cancer (CRC), no study has yet examined the associations between circulating sex hormones and survival among CRC patients. We prospectively assessed the associations of prediagnostic plasma concentrations of estrone, estradiol, free estradiol, testosterone, free testosterone and sex hormone‐binding globulin (SHBG) with CRC‐specific and overall mortality among 609 CRC patients (370 men and 239 postmenopausal women not taking hormone therapy at blood collection) from four U.S. cohorts. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazard regression. We identified 174 deaths (83 CRC‐specific deaths) in men and 106 deaths (70 CRC‐specific deaths) in women. In men, higher circulating level of free testosterone was associated with lower risk of overall (the highest vs. lowest tertiles, HR = 0.66, 95% CI, 0.45–0.99, ptrend = 0.04) and possibly CRC‐specific mortality (HR = 0.73, 95% CI, 0.41–1.29, ptrend = 0.27). We generally observed nonsignificant inverse associations for other sex steroids, and a positive association for SHBG with CRC‐specific mortality among male patients. In women, however, we found a suggestive positive association of estrone with overall (HR = 1.54, 95% CI, 0.92–2.60, ptrend = 0.11) and CRC‐specific mortality (HR = 1.96, 95% CI, 1.01–3.84, ptrend = 0.06). Total estradiol, free estradiol and free testosterone were generally suggestively associated with higher risk of mortality among female patients, although not statistically significant. These findings implicated a potential role of endogenous sex hormones in CRC prognosis, which warrant further investigation. What's new? Premenopausal women with colorectal cancer have a higher 5‐year survival rate than men of the same age, suggesting that female hormones may boost survival. In this prospective study, the authors compared the levels of various sex hormones to mortality rates among 609 CRC patients. In men, they found a beneficial relationship between higher levels of circulating testosterone and lower mortality. In women, though it was not statistically significant, they found a suggestive positive association between higher levels of circulating estrogens and mortality. This is the first study to investigate prediagnostic sex hormone levels as they correlate with CRC mortality. [ABSTRACT FROM AUTHOR]