Small intestinal Neuroendocrine tumours (SI-NET; formerly midgut carcinoids)

SI-NETs have been studied with several different methods in order to identify molecular derangements to understand the underlying mechanisms for tumour development. Initially, we identified the presence of a suspect tumour suppressor gene for SI-NETs on chromosome 18q. Further studies have utilized SNP and expression microarrays, sequencing, SNV analyses, proximity extension assay (OLINKs method) and methylation arrays to reveal characteristics for more or less aggressive tumours. We have identified bad prognostic signs in presence of peritoneal carcinosis. Whole genome sequencing have been performed, and currently single cell and long-read sequencing are being analyzed in order to identify additional derangements, especially on chromosome 18q. We are investigating how different treatments affect SI-NET cell lines in vitro and in vivo. We have been able to demonstrate epigenetic derangements and has shown that metformin reduces growth in SI-NET cell lines and are currently investigating this in animal models.

In a prospective study we have compared classical surgical techniques with a novel handport-assisted laparoscopic method. We have found at least non-inferiority using laparoscopy.

Our previous report regarding avoiding surgery if not R0 can be reached (stadium 4) in patients without abdominal symptoms has been followed up. We note that the among the not operated patients there are extremely few that need surgery, thus supporting our previous conclusion that this group of patients do not need surgery.