Treatment patterns and oncological outcome of patients with advanced small intestinal neuroendocrine tumors: real-world data from the Medical University of Vienna

Philipp Melhorn; Elisabeth Kretschmer-Chott; Ladislaia Wolff; Alexander Haug; Peter Mazal; Markus Raderer; Barbara Kiesewetter

doi:10.1177/17588359221138389

Treatment patterns and oncological outcome of patients with advanced small intestinal neuroendocrine tumors: real-world data from the Medical University of Vienna

Ther Adv Med Oncol. 2022 Nov 19:14:17588359221138389. doi: 10.1177/17588359221138389. eCollection 2022.

Authors

Philipp Melhorn¹, Elisabeth Kretschmer-Chott², Ladislaia Wolff¹, Alexander Haug², Peter Mazal³, Markus Raderer¹, Barbara Kiesewetter⁴

Affiliations

¹ Department of Medicine I, Division of Oncology, Medical University of Vienna, Vienna, Austria.
² Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria.
³ Department of Pathology, Medical University of Vienna, Vienna, Austria.
⁴ Department of Medicine I, Division of Oncology, Medical University of Vienna, Waehringer Guertel 18 - 20, Vienna, A-1090, Austria.

Abstract

Background: Different oncological therapies have been approved for small intestinal neuroendocrine tumors (SI-NETs), but relatively little is known about efficacy and long-term outcome outside of phase III trials.

Methods: This retrospective analysis assessed patients with well-differentiated, metastatic SI-NETs treated at the Medical University of Vienna, an approved European Neuroendocrine Tumor Society (ENETS) Center of Excellence for neuroendocrine tumors. The primary objective was to assess progression-free survival (PFS) following approved therapies, that is, octreotide, lanreotide, peptide receptor radionuclide therapy (PRRT), and everolimus, in a representative real-world collective.

Results: A total of 77 patients receiving systemic treatment for advanced SI-NETs between 2010 and 2021 were included, with a median follow-up time of 82.3 months [95% confidence interval (CI), 57.8-106.8 months]. In the entire collective, the estimated median PFS following first-line therapy was 32.0 months (95% CI, 23.5-40.5 months). Peritoneal carcinomatosis was significantly associated with worse PFS (p = 0.016). Regarding therapeutic strategies and outcome, 59 patients received somatostatin analogs first line and no significant difference in PFS was observed between lanreotide and octreotide (29.3 versus 35.5 months, p = 0.768). Across all treatment lines, 42 patients underwent PRRT (estimated median PFS: 32.0 months; 95% CI, 25.6-38.3 months) and a small subgroup of 7 patients received everolimus (estimated median PFS: 9.2 months; 95% CI, 1.6-17.0 months). For the total cohort, the estimated median OS following first-line therapy was 100.6 months (95% CI, 82.3-118.8 months), but the high proportion of deaths attributed to NET (77.8%) underlines the lethal nature of the disease. No unexpected toxicities were observed.

Conclusions: While peritoneal carcinomatosis emerged as an adverse prognostic factor for PFS in this collective, the long-term outcome of patients treated at a specialized NET center using approved therapies appeared comparable to pivotal studies in SI-NET.

Keywords: PRRT; carcinoid tumor; everolimus; neuroendocrine tumor; real-world data; small intestinal neuroendocrine tumor; somatostatin analogs.