Vitamin D receptor expression in invasive breast tumors and breast cancer survival

• Published in: Breast cancer research : BCR Vol. 21; no. 1; p. 84
• Main Authors: Huss, Linnea, Butt, Salma Tunå, Borgquist, Signe, Elebro, Karin, Sandsveden, Malte, Rosendahl, Ann, Manjer, Jonas
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 29.07.2019; BioMed Central; BMC
• Subjects: Aged; Biomarkers; Breast cancer; Breast Neoplasms - epidemiology; Breast Neoplasms - genetics; Breast Neoplasms - mortality; Breast Neoplasms - pathology; Breast tumors; Cancer and Oncology; Cancer cells; Cancer och onkologi; Clinical Medicine; Death; Estrogens; Female; Gene Expression; Humans; Immunohistochemistry; Kaplan-Meier Estimate; Klinisk medicin; Medical and Health Sciences; Medicin och hälsovetenskap; Middle Aged; Mortality; Neoplasm Grading; Neoplasm Invasiveness; Neoplasm Staging; Patient outcomes; Phenols (Class of compounds); Prevention; Progesterone; Prognosis; Receptors, Calcitriol - genetics; Receptors, Calcitriol - metabolism; Risk factors; Sex hormones; Survival; Sweden - epidemiology; Tissue microarray; Tumors; Vitamin D; Vitamin D receptor; Vitamins; Sweden; Tissue microarray; Breast cancer; Survival; Mortality; Vitamin D receptor
• ISSN: 1465-542X; 1465-5411; 1465-542X
• DOI: 10.1186/s13058-019-1169-1

Vitamin D has been suggested to prevent and improve the prognosis of several cancers, including breast cancer. We have previously shown a U-shaped association between pre-diagnostic serum levels of vitamin D and risk of breast cancer-related death, with poor survival in patients with the lowest and the highest levels respectively, as compared to the intermediate group. Vitamin D exerts its functions through the vitamin D receptor (VDR), and the aim of the current study was to investigate if the expression of VDR in invasive breast tumors is associated with breast cancer prognosis. VDR expression was evaluated in a tissue microarray of 718 invasive breast tumors. Covariation between VDR expression and established prognostic factors for breast cancer was analyzed, as well as associations between VDR expression and breast cancer mortality. We found that positive VDR expression in the nuclei and cytoplasm of breast cancer cells was associated with favorable tumor characteristics such as smaller size, lower grade, estrogen receptor positivity and progesterone receptor positivity, and lower expression of Ki67. In addition, both intranuclear and cytoplasmic VDR expression were associated with a low risk of breast cancer mortality, hazard ratios 0.56 (95% CI 0.34-0.91) and 0.59 (0.30-1.16) respectively. This study found that high expression of VDR in invasive breast tumors is associated with favorable prognostic factors and a low risk of breast cancer death. Hence, a high VDR expression is a positive prognostic factor.