April 30, 2019 (Journal of the Endocrine Society)
This case-series study aimed to uncover possible genetic mutations that may predispose patients with Neuroendocrine tumors (NET) to later develop breast cancer.
This study, led by Dr. Vincent Larouche and 3 colleagues at the University Health Network in Toronto and published in the Journal of the Endocrine Society, looked at 9 cases of co-occurrence between breast cancer and NET. In all cases the subjects were female, with a mean age of 61.4 years for developing breast cancer and 63.4 years for NET. The study took into account various surgical procedures to remove the tumors, tumor size, forms of adjuvant therapy, location of the NET, and numerous additional factors to holistically understand the conditions in each case.
Larouche is awaiting germline candidate gene mutational analyses including MEN1, BRCA1/2, Lynch syndrome, and others, to create a deeper understanding of the connections between each individual case. Nonetheless, this case series further indicates that patients with one malignancy are predisposed to developing another in a different part of the body.
Physicians should strongly consider this during follow-up when they encounter new lesions. Although further research must be done to find the underlying causes, this series provides evidence that NET patients may be at an increased risk for breast cancer.