Predicted 25-hydroxyvitamin D in relation to incidence of breast cancer in a large cohort of African American women

Abstract

BackgroundVitamin D deficiency, which has been linked to an increased risk of colorectal cancer, is particularly common among African Americans. Previous studies of vitamin D status and breast cancer risk, mostly conducted in white women, have had conflicting results. We examined the relationship between predicted vitamin D status and incidence of breast cancer in a cohort of 59,000 African American women.MethodsParticipants in the Black Women’s Health Study have been followed by biennial mail questionnaires since 1995, with self-reported diagnoses of cancer confirmed by hospital and cancer registry records. Repeated five-fold cross-validation with linear regression was used to derive the best 25-hydroxyvitamin D (25(OH)D) prediction model based on measured 25(OH)D in plasma specimens obtained from 2856 participants in 2013–2015 and questionnaire-based variables from the same time frame. In the full cohort, including 1454 cases of incident invasive breast cancer, Cox proportional hazards models were used to compute the incidence rate ratio (IRR) for each quartile of predicted vitamin D score relative to the highest quartile. Predicted vitamin D score for each two-year exposure period was a cumulative average of predicted scores from all exposure periods up to that time.ResultsTwenty-two percent of women with measured 25(OH)D were categorized as “deficient” (<20 ng/mL) and another 25 % as “insufficient” (20–29 ng/mL). The prediction model explained 25 % of variation in measured 25(OH)D and the correlation coefficient for predicted versus observed 25(OH)D averaged across all cross-validation runs was 0.49 (SD 0.026). Breast cancer risk increased with decreasing quartile of predicted 25(OH)D, p for trend 0.015; the IRR for the lowest versus highest quartile was 1.23 (95 % confidence interval 1.04, 1.46).ConclusionsIn prospective data, African American women in the lowest quartile of cumulative predicted 25(OH)D were estimated to have a 23 % increased risk of breast cancer relative to those with relatively high levels. Preventing vitamin D deficiency may be an effective means of reducing breast cancer incidence in African American women.

Association of Vitamin D3 Level with Breast Cancer Risk and Prognosis in African-American and Hispanic Women

“…Their study also identified that serum 25OHD levels were independently associated with breast cancer prognosis in premenopausal women. While some studies failed to show this relationship [ 44 , 48 , 49 ]. The classification of ER status and/or assessment of 25(OH)D3 level (dietary, supplement taken and the time of blood samples collection etc.)…”

Repurposing vitamin D for treatment of human malignancies via targeting tumor microenvironment

“…They found that elevations in serum 25(OH)D concentrations were associated with superior overall survival especially among premenopausal women 37 , strongly suggesting the use of serum vitamin D level as a prognostic marker for breast cancer. Moreover, among African American women, data showed that vitamin D deficiency increased breast cancer susceptibility by approximately 23% 38 , indicating vitamin D intake could be consider as a preventive factor for breast cancer incidence.…”

Lower vitamin D status may help explain why black women have a higher risk of invasive breast cancer than white women

“…There is evidence that breast cancer risk among black women is affected by 25(OH) D concentrations. For example, a prospective study from the Black Women's Health Study found that the incidence rate ratio for invasive breast cancer for lowest vs. highest quartile of predicted 25(OH) D was 1.23 (95% CI, 1.04, 1.46) [3]. For another study, see Ref.…”

“…The proposed mechanisms whereby vitamin D metabolites reduce the risk of breast, colorectal, prostate, and overall cancer include surveillance of cells, reduced angiogenesis around tumors, and antimetastasis actions (see references in [3,4]). However, higher 25(OH) D concentrations have also been found associated with increased risk of colorectal and prostate cancer [4].…”