Plasma fluorescent oxidation products and risk of estrogen receptor-negative breast cancer in the Nurses’ Health Study and Nurses’ Health Study II

Abstract

Purpose Findings from epidemiologic studies of oxidative stress biomarkers and breast cancer have been mixed; although no studies have focused on estrogen receptor-negative (ER−) tumors, which may be more strongly associated with oxidative stress. We examined pre-diagnostic plasma fluorescent oxidation products (FlOP), a global biomarker of oxidative stress, and risk of ER− breast cancer in a nested case-control study in the Nurses’ Health Study (NHS) and NHSII. Methods ER− breast cancer cases (n=355) were matched to 355 controls on age, month/time of day of blood collection, fasting status, menopausal status and menopausal hormone use. Conditional logistic regression models were used to examine associations of plasma FlOP at three emission wavelengths (FlOP_360, FlOP_320, and FlOP_400) and risk of ER− breast cancer. Results We did not observe any significant associations between FlOP measures and risk of ER− breast cancer overall; the RRQ4vsQ1 (95%CI) =0.70 (0.43-1.13), ptrend=0.09 for FlOP_360; 0.91(0.56-1.46), ptrend=0.93 for FlOP_320; and 0.62 (0.37-1.03), ptrend=0.10 for FlOP_400. Results were similar in models additionally adjusted for total carotenoid levels, and in models stratified by age and by total carotenoids. Although, high (vs. low) levels of FIOP_360 and FIOP_400 were associated with lower risk of ER− breast cancer in lean women (body mass index (BMI)<25 kg/m2) but not in overweight/obese women, these differences were not statistically significant (pint=0.23 for FlOP_360; pint=0.37 for FlOP_400). Conclusions Our findings suggest that positive associations of plasma FlOP concentrations and ER− breast cancer risk are unlikely.

A study of the oxidative processes in human plasma by time-resolved fluorescence spectroscopy

“…Furthermore, data obtained from Rebholz’s study indicates that an elevated level of this marker is associated with chronic kidney disease status and its severity 49 . On the other hand, this plasma fluorescent oxidation product was not correlated with the risk of estrogen receptor-negative breast cancer or erectile dysfunction 50 , 51 . Some researchers have tried to use other organic solvents (more apolar) instead of a mixture of ethanol and ether.…”

Oxidative Stress and Breast Cancer Risk in Premenopausal Women

“…Comparing highest to lowest quartiles, the RR for breast cancer was 0.76 (0.55–1.06) for FlOP320 and 0.68 (0.50–0.95) for FlOP_360—results were not further stratified by menopausal status at diagnosis.. 13 In analyses of ER- negative breast cancer (that did not stratify by menopausal status), FlOP_360 (RR Q4vsQ1 =0.40; 95% CI: 0.20–0.81) and FlOP_400 (RR Q4vsQ1 =0.42; 95% CI: 0.22–0.82) were inversely related to ER- breast cancer risk among women with BMI <25 kg/m 2 , but not in higher BMI groups (FlOP_360 RR Q4vsQ1 =1.10; 95% CI: 0.54–2.24 and FlOP_400 RR Q4vsQ1 =0.96; 95% CI: 0.46–1.99). 38 …”