Endocrine Abstracts

Introduction: The treatment of choice for parathyroid carcinoma (PC) is a radical en bloc resection. Treatment options for patients with metastatic PC are limited especially if a complete tumor removal cannot be performed. We present four cases of PC patients with multiple metastasis and refractory hypercalcemia that eventually received a multikinase inhibitor with different response on therapy.

Clinical cases: The first patient was a 27-year-old woman with metastatic PC in the right lung (2.9 cm and 2.2 cm). Five months after the thoracoscopic resection of the lung lobe, PTH was 720 pmol/l, (15-65), ca – 2.74 mmol/l (2.10–2.55). Diffusional MRI (DW-MRI) showed multiple lesions in both lungs (0.2–0.5 cm). Based on the reports of successful sorafenib treatment in metastatic PC by Dr. Lerario A.M. we started a targeted therapy with 400 mg of sorafenib 2 times a day. The therapy showed good results: over the next three years of sorafenib treatment, we’ve observed stabilization of the metastatic process according to PET/CT (lesions in lungs without uptake of the 18-fluorodeoxyglucose) as well as normocalcemia and significant reduction of PTH in lab tests. The second and the third cases are very similar. Both patients (76 and 61 years old woman underwent 5 surgeries on the neck because of the recurrent disease and both had metastasis in lungs. Based on our own experience we started the sorafenib therapy. After a year, despite persistent elevated levels of PTH (2000–2500 pg/ml) and Ca (2.7–2.9 mmol/l) the PET/CT showed the significant reduction in metastases size regarded as the stabilization of the process. So we decided to continue the sorafenib therapy. The fourth patient (64-years old woman) had the most aggressive PC course with multiple metastases in the neck lymph nodes, lungs, liver, left clavicle, C6-7 and L4 vertebras. She referred to our centre after 6 reoperations on the neck, 3 sessions of radiation therapy (SOD 87.4 Gy), ineffective chemotherapy with capecitabinum (Ca− 3,10 mmol/l, PTH- 2090 pg/ml). 4 weeks after we initiated sorafenib therapy and noted a dramatic decrease in PTH to 98.2 pg/ml and Ca to 2,15 mmol/l (tested twice). However three months after the start treatment PET/CT showed the increase in metastasis size and the newly formed lesions. The sorafenib therapy was stopped because of the ineffectiveness.

Conclusions: Sorafenib seems to be a promising drug for targeted therapy in some PC cases.