An association between invasive breast cancer and familial idiopathic hyperparathyroidism: a case series and review of the literature.

The possibility of an association between primary hyperparathyroidism and breast cancer has been postulated. We report here a sibship with three premenopausal breast cancers and hyperparathyroidism, and no detectable BRCA or MEN1 gene mutations. We explore genetic and molecular rationales for an association between these metabolic and neoplastic processes.