426 Background: Pancreatic neuroendocrine tumors (pNETs) are rare malignancies with an age-adjusted annual incidence of 0.32/100,000, with metastatic disease at diagnosis occurring in 64%. Patients with advanced disease are considered for surgery/ablative therapy (SG) or systemic therapy (ST), including chemo- and targeted therapy, somatostatin analogues, and peptide receptor radiotherapy (PRRT). Optimal sequence of therapy is unknown and we sought to characterize sequential treatment patterns in patients with metastatic pNETs and overall survival (OS). Methods: Patients diagnosed with metastatic pNETs referred to the BC Cancer Agency between 2000-2013 and received more than one line of therapy were reviewed. Results: Of 151 patients, 81 received one line of therapy while 45 patients received >1 treatment. Median age was 55.1 years (IQR 47.4-64.8) and 23 (51%) were male. Sites of metastases included liver (n=33), lymph nodes (n=5), lung (n=1), peritoneum (n=2), and bone (n=5). Median time to start of therapy was 1.5 months (IQR 0.4-3.0). First-line SG was associated with increased OS compared to first-line ST (88.9 vs. 38.2 months; p=0.004). There was no difference in OS between patients receiving second-line SG or ST, measured from start of second-line therapy. Second-line chemotherapy was associated with decreased PFS compared to alternate treatments, both after first-line chemotherapy (0.7 vs. 5.8 months; p=0.002) and after other treatments (4.8 vs. 16.7 months; p=0.002). Median length of follow-up was 48.3 months. Conclusions: We present the sequential treatment patterns of patients with metastatic pNETs. Results confirm the primary role of SG, reserving ST for secondary therapy. Upon progression, choice of second-line therapy was not prognostic and may be chosen based on disease and patient characteristics. [Table: see text]
Molecular pathogenesis and targeted therapy of sporadic pancreatic neuroendocrine tumors
