Association between vitamin D and calcium intake and breast cancer risk according to menopausal status and receptor status in Japan.
Although several studies have investigated the possible association between elevated vitamin D and calcium intake and low breast cancer risk, findings have been inconsistent. We conducted a case-control study to clarify the association between vitamin D and calcium intake and breast cancer risk among pre- and post- menopausal women in Japan. We also investigated whether these effects were modified by tumor receptor status, specifically estrogen receptor (ER), progesterone receptor (PR), or human epidermal growth factor receptor-2 (HER2) status. We examined 1803 breast cancer patients and 3606 age- and menopausal status-matched noncancer controls. Among cases, 713 were assessed for ER, PR, and HER2 status. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using conditional or unconditional logistic models adjusted for potential confounders. A significant inverse association was observed between vitamin D and calcium intake and breast cancer risk among all subjects, with top quartile ORs of 0.76 (95% CI, 0.63-0.90; trend P = 0.001) and 0.83 (95% CI, 0.69-0.99; trend P = 0.038), respectively. In analyses stratified by menopausal status, a significant association between risk and vitamin D was observed only among premenopausal women (trend P < 0.001), whereas that between risk and calcium intake was seen only among postmenopausal women (trend P = 0.022). Heterogeneity by menopausal status for these associations was statistically significant. This association was modified by tumor receptor status. These findings suggest that the protective effects of vitamin D and calcium intake against breast cancer risk may differ by menopausal status and receptor status.
Division of Epidemiology and Prevention, Aichi Cancer Center Research Institute, Nagoya, Japan.
Takakazu
T
Kawase
Keitaro
K
Matsuo
Takeshi
T
Suzuki
Kaoru
K
Hirose
Satoyo
S
Hosono
Miki
M
Watanabe
Masaki
M
Inagaki
Hiroji
H
Iwata
Hideo
H
Tanaka
Kazuo
K
Tajima
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000737:chemistry / Q000209:etiology*; D002136:Calcium, Dietary / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008593:Menopause; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D011960:Receptors, Estrogen / Q000032:analysis*; D011980:Receptors, Progesterone / Q000032:analysis*; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000097:blood
D002136:Calcium, Dietary; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D014807:Vitamin D; C104450:25-hydroxyvitamin D; C508053:ERBB2 protein, human