Vitamin D (vD) deficiency (def) in breast cancer (BC) patients (pts)

Abstract

11082 Background: Vitamin D metabolism is important for maintaining bone health and perhaps cancer prevention. Prior studies have reported vD def in 88% of brca pts (Lonning et al ASCO 2006 abst 554), and 79% of women (Chlebowski et al ASCO 2006 abst 6) . Methods: In order to determine the frequency of vD def, we studied 41 consecutive brca pts. Levels of vD were correlated with clinical features. Pts were classified as vD def if 25OH D <20, 1.25 diOH D <14, or D3 <20. Insufficiency (ins) of vD was 25OH D 20–29. Results: 8 pts had vD def (19.5%). This was more common in young pts <60 (37.5%) compared to older pts (8%) (p4) in 5/6 pts <60 and 5/7 older pts. vD def did not correlate with bone disease: 25% def in pts without bone disease, 17% in pts with osteopenia, and 17% in pts with osteoporosis. In older pts, vD was normal in 12/14 pts on anastrazole, and in 7/11 pts not on anastrazole, indicating no relation of anastrazole to vD def. Bisphosphonate (bis) usage was slightly higher in older pts (60%) versus younger pts (38%) but not significantly (p<0.2). While only 19% of pts on bis had vD ins or def, 50% of pts not on bis had ins or def vD (p<0.05). Although only 5% of pts on bis had vD def, 30% of pts not taking bis had vD def (p<0.05). Conclusions: In brca pts, vD def is less than reported, but still frequent. All brca pts should be tested for vD periodically. VD def may be less frequent in pts on bis, and confirmatory trials should be performed. VD levels should also be monitored even if pts report taking vD. VD def or ins should be treated and monitored by oncologists. Since vD may be related to cancer incidence, and to bone disease, all brca trials collecting data on bone events, bone density, and second cancers should also report relationship to vD levels in individual study participants. No significant financial relationships to disclose.