Long term survival and clinical efficacy in patients with advanced pancreatic and small bowel metastatic neuroendocrine tumours (GEP-NET) after i.v. 90Y DOTATATE

Objectives Comparison of overall survival (OS) and clinical efficacy between patients with pancreatic and small bowel advanced, metastatic, progressive neuroendocrine cancer after i.v. 90Y DOTATATE.

Methods Sixty seven pts with histologically proven GEP-NETs were treated with 90Y DOTATATE, including N=30 with pancreas and rest with small bowel. The primary end point was overall survival (OS) and second end point was progression free survival (PFS) and clinical efficacy of tumor response on PRRT.

Results Median OS for all pts was 40 months (CI+/-95% 36.6-46.9), patients with pancreatic NET - 42 M (34.0 - 48.2), compare to 40 M (34.7 - 50.1) in those with small bowel, (P>0.05). Median PFS was 26 months (26.5 - 36.2) for all patients, pancreas subgroup 25 M (CI 20.8 - 33.2), compare to 28 M (27.5 - 42.1) in small bowel subgroup. Outcome dependent on previous systemic therapy for all patients and for selected groups those with pancreatic and small bowel tumor presented as follows: (1) in the subgroup receiving somatostatin analogues and then PRRT OS and PFS results were as follows: 47 vs 40 M and 24 vs 26 M, (2) in subgroup without previous SST analogues: OS and PFS were: 37 vs 38 M and 26 vs 32 M, (3) in the subgroup with previous chemotherapy: OS and PFS were as follows: 43 vs 38 M and 23.5 vs 25 M. The last subgroup (4) where no chemotherapy was used the results obtained : OS was 42 vs 49.5 M and PFS 26.5 vs 31.5 M. Analyzed the prognostic and predictor factors indicated better survival in the subgroups of women : median OS 50.0 vs 33.5 and median PFS 29.0 vs 23.5 in both subgroups as well.

Conclusions 90Y DOTATATE PRRT is effective in long term outcome (OS) in patients with advanced progressive pancreatic and small bowel GEP-NET. This therapy is relatively safe as initial systemic therapy and after previous treatment with chemotherapy or somatostatine analogues