Dietary cadmium and risk of breast cancer subtypes defined by hormone receptor status: A prospective cohort study

Abstract

Diet is the primary source of cadmium-a proven Group 1 human carcinogen-for non-smokers. Observational studies investigating the effect of cadmium from food sources on breast cancer risk have produced inconsistent results. We examined the association between dietary cadmium and risk of breast cancer defined by estrogen receptor (ER), progesterone receptor (PR) and HER2 status, in 8924 women recruited to a prospective study between 1987 and 1992. Dietary cadmium intake was estimated using a semi-quantitative food frequency questionnaire at baseline. During a median of 22 years of follow-up, 451 incident cases of breast cancer were identified through the Varese Cancer Registry. Multivariable-adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for breast cancer and receptor-defined breast cancer subtypes were estimated for quintiles of dietary cadmium intake, adjusting for confounding factors. Mean dietary cadmium intake was 7.8 (standard deviation 1.4) μg/day. Women with highest quintile of cadmium intake had a greater risk of breast cancer (HR 1.54; 95% CI, 1.06-2.22; p trend = 0.028) than those with lowest quintile of intake. Women premenopausal at recruitment had HR = 1.73 (95% CI, 1.10-2.71, highest vs. lowest quintile); postmenopausal women had HR = 1.32 (95% CI, 1.05-1.66 for each standard deviation increase in cadmium). Cadmium-related risk of breast cancer did not vary with ER, PR or HER2 status (p-heterogeneity not significant). These findings support the hypothesis that dietary cadmium is a risk factor for breast cancer.

Dietary Intake of Acrylamide and Risk of Breast, Endometrial, and Ovarian Cancers: A Systematic Review and Dose–Response Meta-analysis

“…In addition, we accounted for major established or putative risk factors such as body weight, smoking habits, hormone replacement therapy/oral contraceptive use, and partially lack of physical activity, and alcohol intake (64-67) by using the most adjusted estimates from included studies. However, we acknowledge that unmeasured confounding may still have influenced these findings, with reference to environmental risk factors such as cadmium (68)(69)(70), pesticides (71)(72)(73) or air pollution (74)(75)(76)(77). Moreover, food frequency questionnaires used for acrylamide intake estimation in the included studies did not generally collect information about cooking methods, potentially affecting the reliability of exposure assessment (78) and contributing to heterogeneity in results.…”

Environmental exposures during windows of susceptibility for breast cancer: a framework for prevention research

“…Most [153–155, 159, 162, 163], but not all [158, 164], epidemiologic studies of postmenopausal women or all ages combined show risk estimates in the 0.73 to 1.01 range (Table 2). Two studies show greater risk associated with cadmium exposure for premenopausal women than for postmenopausal women [156, 165], whereas two other studies show the reverse [157, 166], with additional studies describing generally null associations for both groups [160, 161, 167, 168]. Stratification by estrogen receptor status does not reveal a consistent pattern.…”

Beneficial Impact of an Extract from the Berries of Aronia melanocarpa L. on the Oxidative-Reductive Status of the Submandibular Gland of Rats Exposed to Cadmium

“…This heavy metal is characterized by strong cumulative properties, and thus its content in the body increases with the duration of exposure and may be a cause of damage to various organs and systems [3,14]. Recent epidemiological studies provide more and more evidence that environmental exposure to this xenobiotic, nowadays occurring in economically developed countries, creates a threat to the health of the general population, mainly including a risk of damage to the kidney, liver, cardiovascular system, and skeleton, as well as the development of cancer and the deterioration of cognitive functions such as hearing and vision [3,9,13,[15][16][17][18]. It has been revealed that numerous effects of toxic action of cadmium, including the damaging impact on the organs of the oral cavity, result from its pro-oxidative properties [5,14,[19][20][21][22][23].…”

“…Because current environmental exposure to cadmium creates a threat to the health of the general population [3,8,10,11,13,[15][16][17][18] and the lifetime human exposure to this xenobiotic will increase [9][10][11], the attention of researchers in recent years has been focused on finding effective ways to prevent the unfavourable health effects of exposure to this heavy metal. Taking into account the strong pro-oxidative properties of cadmium and the involvement of oxidative stress in the mechanisms of its damaging impact on various organs and systems [3,5,14,[19][20][21][22][23], the greatest interest among the possible protective agents has been paid to natural products characterized by strong antioxidative properties, including polyphenol-rich ones [14,[24][25][26].…”