Thanks Hopeful - great article (=:
Here is a study suggesting vitamin D may have a particular relevance in ER (estrogen receptor) based cancers.
http://www.biomedcentral.com/1471-2407/10/483
Alterations in Vitamin D signalling and metabolic pathways in breast cancer progression: a study of VDR, CYP27B1 and CYP24A1 expression in benign and malignant breast lesions Vitamin D pathways unbalanced in breast lesions
Nair Lopes1, Bárbara Sousa1, Diana Martins1, Madalena Gomes1, Daniella Vieira2, Luiz A Veronese3, Fernanda Milanezi1, Joana Paredes1, José L Costa1 and Fernando Schmitt1,4*
Conclusions
From this study, we conclude that there is a deregulation of the Vitamin D signalling and metabolic pathways in breast cancer, favouring tumour progression. Thus, during mammary malignant transformation, tumour cells lose their ability to synthesize the active form of Vitamin D and respond to VDR-mediated Vitamin D effects, while increasing their ability to degrade this hormone.
Paragraph re ER cancers
Vitamin D receptor (VDR)
"An interesting finding is the correlation between the expression of the VDR and the ER in both in situ and invasive carcinomas. In fact, the VDR is expressed in most ER-positive cases (54.7% in in situ carcinomas and 65.5% in invasive tumours).
It is thought that one of the VDR functions is to counteract oestrogen-mediated proliferation and maintain differentiation [12]. Indeed, data support the concept that the anti-tumour effects of Vitamin D and its analogues on ER-positive human breast cancer cells are mediated through the down regulation of the ER itself and the attenuation of oestrogen responses, such as breast cancer cell growth [29,30]. Thus, being the VDR mostly expressed in ER-positive carcinomas, Vitamin D or its analogues may become an alternative therapy for these tumours in cases of resistance to ER-targeted therapy. "