Better survival associated with successful vitamin D supplementation in non-metastatic breast cancer survivors

Abstract

Abstract Background We aimed to clarify whether successful vitamin D supplementation could predict improved survival in breast cancer (BC) survivors after completion of adjuvant treatment. Materials and Methods Patients were classified into four groups based on changes of 25(OH)D level during the treatment follow-up. Log-rank statistics were used to compare survival distributions among groups. ORs and 95% CIs were given for mortality ratios. Results The risk of death in group II with low 25(OH)D levels was 4.2 times higher than in group I with high 25(OH)D levels. (OR = 4.17 (95% CI = 1.46–11.91), P = 0.008) and the risk of death in group IV whose 25(OH)D levels never increased was 4.3 times higher (OR = 4.29 (95% CI = 1.13–16.3)). According to the log-rank test, life expectancy was significantly higher in group II compared to group I (P = 0.017) and group III (P = 0.001). Group IV had significantly lower survival times than group III (P = 0.021). Conclusions Vitamin D supplementation may play an important role in the response of the received treatments and provide a lower mortality rate and better overall -free survival (OFS) and disease-free survival (DFS) to BC patients. However, we observed a sign of poorer BC survival still after sufficient vitamin D supplementation.