Effects of metformin versus placebo on vitamin B12 metabolism in non-diabetic breast cancer patients in CCTG MA.32.

Background: Metformin is associated with low levels of vitamin B12 (VitB12) in patients with diabetes. The CCTG/MA.32 trial investigates the effects of metformin vs placebo on breast cancer (BC) outcomes in non-diabetic high-risk BC patients.

Prognostic associations of 25 hydroxy vitamin D in NCIC CTG MA.21, a phase III adjuvant randomized clinical trial of three chemotherapy regimens in high-risk breast cancer.

Low vitamin D levels have been associated with poor breast cancer outcomes in observational studies. We examined the association of vitamin D blood levels with relapse-free survival (RFS), breast cancer-specific survival (BCSS), and overall survival (OS) in the MA.21 randomized clinical trial.