Endocrine Abstracts

Introduction: The NETTER 1 trial resulted in markedly longer progression-free survival (PFS), with preliminary evidence of an overall survival benefit. We report the results of PFS and safety of (177Lu)-DOTATATE in patients treated in our hospital between 2014 and 2017.

Methods: Transversal and descriptive study of 22 patients with advanced, progressive, somatostatin receptor-positive tumors who had received previous treatments. All of them were treated with (177Lu)-DOTATATE. Results are expressed in average(SD) or percentage (%). SPSS version 2.2 was used for statistical analysis.

Results: 59.1%(13) were women, with an average age of 53.32(15.2). Histological classification was: 16(72.7%) well-moderate differentiated neuroendocrine tumors (NETs) (8 pancreatic, 4 midgut, 2 lung and 2 unknown primary), 5(22.7%) paragangliomas and 1(4.5%) follicular thyroid carcinoma. At the time of administration of (177Lu)-DOTATATE, 21 patients were in metastatic stage, and one had unresectable bilateral neck paragangliomas. The localization of the metastasis was: liver 68.2%(15), bone 45.5%(10), lymph nodes 27.3%(6) and lungs 9.1%(2). All patients had received previous treatments: 2 underwent surgery exclusively, 4 were treated with somatostatin analogues (SA), 4 with SA and surgery, and the rest of patients with another systemic therapies in addition to SA and surgery: tyrosine-kinase inhibitors, mTOR inhibitors, and standard chemotherapy. 177Lu-DOTATATE was infused every eight weeks. 16 patients have already finished the treatment: 14 patients received 4 doses (59.1%), 2 received only 3 due to the excellent response. Three patients have not received yet complete treatment, and finally 3 remaining patients died during the treatment. At the data-cutoff date PFS was of 12.86(12.43) months. Ten (45.5%) patients had adverse events related to the treatment: 1 asthenia, 4 self-limited nausea, vomiting or abdominal pain, and 5 haematologic events (3 mild-moderate anemia, 2 pancytopenia, one of them with fatal ending). During the follow-up, 5 patients have died.

Conclusions: In real world practice, treatment with (177Lu)-DOTATATE not only shows benefit in advanced intestinal NETS but also in other patients with metastatic disease, previous treatments, and positive somatostatin-receptor expression. 177Lu seems to have favorable results attending to PFS and safety.