Abstract P6-07-32: Vitamin D as a potential biomarker of aggressiveness in non-metastatic breast cancer

Abstract

Abstract Background: Vitamin D (VD) is known to play a proapoptotic and antiproliferative role in cancer cells. Recent studies have shown that low serum VD may be associated with worse prognosis in cancer patients (pts). However, levels of VD are not routinely measured in daily clinical practice. Methods: We retrospectively evaluated pts diagnosed with non-metastatic breast cancer between January 2010 and November 2015. Serum 25(OH)-VD and bone density were measured any time after surgery, during either adjuvant treatment or the follow-up. VD insufficiency (VDi) and deficiency (VDd) were defined as serum VD levels of 20-30 ng/ml and <20 ng/ml, respectively. Possible association between VD levels and baseline characteristics as AJCC stage, inmunohistochemistry (IHC) subtype, ki67 and differentiation grade were studied. Correlation between synchronous densitometry and VD levels was also evaluated. Results: 98 pts that met the above described criteria were included in the analysis. Median (M) VD was 20.68 (range, 3 – 65.60). 72.4 % of pts had VD under 30 ng/ml (23.4% had VD insufficiency and 49% had deficiency). AJCC stages II-III were more frequent in patients with low VD levels (Normal: 48%; VDi: 52%; VDd: 65%). VD levels were similar across IHC subtypes (Normal VD levels: Luminal A: 51%; Luminal B: 30%; Triple Negative: 14%; VDi: LA: 52%; LB: 35%; TN: 13%; VDd: LA: 39%; LB: 48%; TN: 13%). Undifferentiated tumors were more frequent among pts with VD levels <30ng/ml (Normal: 27%; VDi: 45%; VDd: 45%). Elevated Ki67 was more commonly found in pts with lower VD (Normal: 40%; VDi: 40%; VDd: 61%). Our results did not show correlation between densitometry and VD levels. Conclusions: Lower levels of 25(OH)-Vitamin D may be associated with more advanced and aggressive non-metastatic breast cancer. 25(OH)-VD should be evaluated at diagnosis. Although it may be a promising biomarker, further research in this field is required.Background: Vitamin D (VD) is known to play a proapoptotic and antiproliferative role in cancer cells. Recent studies have shown that low serum VD may be associated with worse prognosis in cancer patients (pts). However, levels of VD are not routinely measured in daily clinical practice. Methods: We retrospectively evaluated pts diagnosed with non-metastatic breast cancer between January 2010 and November 2015. Serum 25(OH)-VD and bone density were measured any time after surgery, during either adjuvant treatment or the follow-up. VD insufficiency (VDi) and deficiency (VDd) were defined as serum VD levels of 20-30 ng/ml and <20 ng/ml, respectively. Possible association between VD levels and baseline characteristics as AJCC stage, inmunohistochemistry (IHC) subtype, ki67 and differentiation grade were studied. Correlation between synchronous densitometry and VD levels was also evaluated. Results: 98 pts that met the above described criteria were included in the analysis. Median (M) VD was 20.68 (range, 3 – 65.60). 72.4 % of pts had VD under 30 ng/ml (23.4% had VD insufficiency and 49% had deficiency). AJCC stages II-III were more frequent in patients with low VD levels (Normal: 48%; VDi: 52%; VDd: 65%). VD levels were similar across IHC subtypes (Normal VD levels: Luminal A: 51%; Luminal B: 30%; Triple Negative: 14%; VDi: LA: 52%; LB: 35%; TN: 13%; VDd: LA: 39%; LB: 48%; TN: 13%). Undifferentiated tumors were more frequent among pts with VD levels <30ng/ml (Normal: 27%; VDi: 45%; VDd: 45%). Elevated Ki67 was more commonly found in pts with lower VD (Normal: 40%; VDi: 40%; VDd: 61%). Our results did not show correlation between densitometry and VD levels. Conclusions: Lower levels of 25(OH)-Vitamin D may be associated with more advanced and aggressive non-metastatic breast cancer. 25(OH)-VD should be evaluated at diagnosis. Although it may be a promising biomarker, further research in this field is required. Citation Format: Baraibar I, Martín P, Sala P, Gardeazabal I, Salas D, Zubiri L, Santisteban M, Espinós J, Aramendía JM. Vitamin D as a potential biomarker of aggressiveness in non-metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-07-32.