Background
An association between higher serum calcium (Ca2+) levels and breast cancer has been previously reported. However, little is known regarding the relationship between serum Ca2+ levels and the expression of Ca2+ channels in the presence of breast microcalcifications.
Conclusion
We observed an increase in the expression of TRPM7 and TRPC1 Ca2+ channels in infiltrating ductal carcinoma samples with microcalcifications, whereas no change in serum Ca2+ levels was observed. Together these data suggest that increased expression of these channels might lead to an increase in intracellular Ca2+ levels thereby restoring serum Ca2+ levels, but these can contribute to the breast microcalcifications. However, future studies exploring the intracellular Ca2+ levels as well as the role of TRPM7 and TRPC1 function according to BI-RADS scores are needed.
Methods
A retrospective analysis of women newly diagnosed with breast microcalcifications was performed based on the Breast Imaging Reporting and Data System (BI-RADS). The expression of TRPC1, TRPC3, and TRPM7 using normal biopsy without microcalcifications (controls) and infiltrating ductal carcinoma with microcalcifications was evaluated.
Results
Data on 138 women were analyzed. Seventy percent of women had a BI-RADS score (1-3) corresponding to benign disease. Seventy-six percent of women with a BI-RADS score (4 or 5) were diagnosed with breast cancer, 56% were cancers in situ, and 93% were infiltrating ductal carcinomas. No difference in the distribution of corrected serum Ca2+ levels between BI-RADS scores (1-3) and BI-RADS scores (4-5) (P = 0.82) was observed. Serum Ca2+ levels were similar in women without cancer and women diagnosed with breast cancer (P = 0.94). However, the expression of TRPM7 and TRPC1, but not TRPC3, Ca2+ channels were increased in infiltrating ductal carcinoma samples with microcalcifications when compared with age-matched controls without calcification or cancer.