Is mammographic microcalcification of biological significance?

Mammographic microcalcification is a feature of a proportion of breast cancers. Its occurrence does not appear to be significantly associated with age or primary tumour size. Lymph node involvement by tumour is present in 50% of patients with mammographic microcalcification in relation to the primary tumour, but only 24% of patients without microcalcification. A significantly larger number of lymph nodes (61 of 241 nodes) are involved with tumour in patients with, in comparison to those without (59 of 476 nodes) microcalcification (P < 0.001, chi 2 test). These differences suggest a biologically significant role for the deposition of calcium in microcalcifications, which may relate to the process of tumour cell metastasis. This may be of importance in the assessment of patients with cancers which demonstrate microcalcification on mammography.