Endocrine Abstracts

Introduction: Women with breast cancer (BC) have an increased risk of developing thyroid cancer (TC), specifically papillary and follicular thyroid carcinomas at a median of 5 years. The aim of the present retrospective study is to describe the clinical characteristics of women who present this association.

Results: A total of 260 patients with an authenticated TC who were the median age at diagnosis is 41 years old (36–65). All our patients live in areas of moderate iodine deficiency. The frequency of the association of BC-TC =6/260 (4.3%). The median duration between the two diagnoses =24 months (12–84). The BC has always preceded theTC. The histopathological aspects are respectively for the BC: invasive ductal carcinoma (n=4) invasive lobular carcinoma (n=2) and TC: pure vesicular (n=2); Papillary (n=4). All these women underwent chemotherapy, hormone therapy and radiotherapy for BC and total thyroidectomy and an irradiation (100 mCI 131) for TC.

Discussion: The coexistence BC and TC is not fortuitous but the related pathophysiological mechanisms remain poorly elucidated Exposure to estrogens and to thyroid-stimulating hormones may play a role in the development of breast cancer or thyroid cancer. Radiation exposure is also a well-known risk factor for the development of TC, so a germline mutation could be responsible for the connection between breast and thyroid cancers.

Conclusion: The association of these two pathologies is not incidental and should lead otherwise to the systematic screening of the thyroid cancer in women with breast cancer.