Association between 8-oxo-7,8-dihydro-2′-deoxyguanosine Excretion and Risk of Postmenopausal Breast Cancer: Nested Case–Control Study

Abstract

Background: Oxidative stress may be important in carcinogenesis and a possible risk factor for breast cancer. The urinary excretion of oxidatively generated biomolecules, such as 8-oxo-7,8-dihydro-2 0 -deoxyguanosine (8-

The Role of Biomarkers of Oxidative Stress in Breast Cancer Risk and Prognosis: A Systematic Review of the Epidemiologic Literature

“…Samples from cases were collected at cohort entry within 5 years of diagnosis. Overall, a positive association between 8-oxodG and risk of breast cancer was observed, 30 and when stratified by ER status, the positive association was limited to women with ER+ breast cancer. In 2015, a large nested casecontrol study focusing on premenopausal breast cancer in the Nurses' Health Study I and II studies reported some evidence for an inverse association for FlOPs and premenopausal breast cancer (e.g., FlOP_360 highest quartile levels [compared with lowest quartile levels] were associated with a 32% decreased risk of premenopausal breast cancer in adjusted models).…”

“…28 One study reported that the positive association of 8-oxodG was only present in women with low dietary iron intake; p-value for interaction = 0.02. 30 Oxidative stress biomarkers and breast cancer prognosis Study design and study population details are displayed in Table 3 and results are summarized in Table 4. We identified a total of eight studies that investigated biomarkers of oxidative stress in association with breast cancer prognosis with various oxidative stress biomarkers in blood, urine, and tissue utilized.…”

“…Another limitation is that breast cancer has been shown to be an etiologically heterogeneous disease, with studies showing modification of known associations by tumor subtype. 58,59 However, to date, only two studies examined associations of biomarkers of oxidative stress with breast cancer risk by tumor ER status, 30,47 and no studies have evaluated associations by molecular subtypes. Finally, differences in how menopausal status was defined across studies, a known methodological limitation in epidemiological studies considering menopausal status, 60 or lack of stratifying results by menopausal status could have contributed to inconsistencies in findings.…”

“…20,28 Biomarkers of oxidative stress have been investigated for their association with the development and progression of several cancer types, and in particular breast cancer, as oxidative stress mechanisms may be involved in several known breast cancer risk factors, including obesity and daily alcohol intake, and circulating estrogen levels. [29][30][31][32][33][34] Breast cancer cells have been shown to be susceptible to oxidative damage and have high levels of oxidative stress, including protein damage, DNA damage, and lipid peroxidation. 9,35 Furthermore, several breast cancer risk factors may alter levels of endogenous oxidative stress.…”

Controlled exposure to diesel exhaust and traffic noise – Effects on oxidative stress and activation in mononuclear blood cells

“…A study of human subjects exposed to airport noise overnight in their home showed endothelial dysfunction, which was attenuated by administration of the antioxidant vitamin C [10]. Converging lines of evidence indicate that exposure to traffic noise is associated with the risk of breast cancer [11], of which risk factors for the latter could also include oxidative stress and urinary 8-oxodG excretion [12]. Accordingly, traffic-related air pollution and noise not only share sources, but also adverse health effects and these exposures might converge in some of the mechanistic pathways and act synergistically.…”