Israel: Bone mineral density (BMD) might be considered a biomarker for breast cancer risk, suggests a recent study in the journal npj Breast Cancer.
Results of the study showed that women diagnosed with breast cancer have higher BMD on dual-energy x-ray absorptiometry (DEXA) scan compared to women with similar characteristics but without breast cancer.
After menopause, the incidences of both breast cancer and osteoporosis increase. Estrogen is critical for the maintenance of bone integrity; deficiency of which results in accelerated bone loss and decreased BMD, and a propensity for osteoporotic fractures. Given this, estrogen may have opposing effects on health i.e. increasing the risk of breast cancer and improving bone health by increasing BMD.

Considering the above, Merav Fraenkel, Ben-Gurion University of the Negev, Beer Sheva, Israel, and colleagues aimed to compare DEXA BMD between women newly diagnosed with breast cancer and matched controls without breast cancer in a prospective matched cohort study.
For this purpose, the researchers prospectively enrolled women newly diagnosed with breast cancer treated between April 2012 and October 2017. They established a control group of women with negative mammography or breast ultrasound, matched 1:1 by age, body mass index, parity, and the use of hormone replacement therapy. Those with DXA BMD and lab assessments at enrollment were included.
464 out of 869 women with newly diagnosed breast cancer, signed informed consent. Of the 344 who completed the study protocol, 284 were matched to controls. Overall, the mean age was 58 years.
Following are the study's salient findings:
Compared to the control group, for the breast cancer group, the mean vitamin D level was lower (48.9 ± 19.0 vs. 53.8 ± 28.8 nmol/L); and mean values were higher of total hip BMD (0.95 ± 0.14 vs. 0.92 ± 0.12 g/cm2), T score (−0.38 ± 1.17 vs. −0.68 ± 0.98), and Z score (0.32 ± 1.09 vs. 0.01 ± 0.88).
Among the women with breast cancer, no correlations were found of baseline BMD with tumor size or grade, nodal involvement, or breast cancer stage.
"Our prospective case-control study showed that among women diagnosed with breast cancer had higher femoral neck DXA Z scores, and total hip BMD, Z, and T scores compared to matched controls without breast cancer, despite significantly lower mean vitamin D levels in those with breast cancer," the authors wrote.
To conclude, DXA BMD parameters were not found to be associated with breast cancer characteristics at diagnosis. Also, DXA BMD was not associated with mortality among those with breast cancer.
Reference:
Fraenkel, M., Novack, V., Mizrakli, Y. et al. Bone mineral density in women newly diagnosed with breast cancer: a prospective cohort study. npj Breast Cancer 8, 21 (2022). https://doi.org/10.1038/s41523-022-00388-z