Prof Aurel Perin talks to ecancer.tv about the pathological classification of neuroendocrine tumours (NETs). The classification of NET tumour type, grade, and stage is essential in order to determine what course of treatment is appropriate for each patient. Prof Perin discusses how these rare tumours are caused and the effects they have, and clarifies the need for predictive biomarkers and the collection of tissues for biobanks.
This programme was supported by BAYER.
World Congress on Gastrointestinal Cancer 14, Barcelona, Spain
Neuroendocrine tumours of the pancreas
Professor Aurel Perren – University of Bern, Switzerland
Neuroendocrine neoplasias are a rare tumour that can arise in all organs and they have the special capacity of producing hormones that can lead to clinical symptoms and, in about half the tumours, the hormones are the main cause of the illness of the patient and can lead to life-threatening symptoms.
What were you speaking about at the congress?
As a pathologist my task was to explain what are the up-to-date requirements of a pathology examination of such neuroendocrine tumours. There have been changes in classification, since 2010 we use a new WHO classification, and I explained how this classification works and what are the essential parts of this classification which should be included in every pathology report.
Could you explain more about these classifications?
In every tumour classification there is tumour type, which can be a neuroendocrine tumour or a neuroendocrine carcinoma and there is grading information. Grading of neuroendocrine tumours is done according to mitotic index and Ki-67 proliferation index and the third part, which is an integral part of any tumour classification actually, is the staging so the TNM staging according to the ENET or UICC proposal.
Is there a common phenotype or genotype for these tumours?
There is a common phenotype, the so-called neuroendocrine phenotype, which is the similarity of these tumour cells to neurons. In daily practice pathologists prove this phenotype by immunohistochemistry for synaptophysin and chromogranin a; actually there is not one common genotype of these tumours, they differ according to the organ they arise in and some of them also according to the peptide hormone they produce.
What information do you need from an oncologist?
We need the information on the site of the biopsy, on the type of problems the patient faces. Actually for the functional endocrine tumours we are really dependent on the communication of the clinical hormonal syndrome, without this information we are not able to do the correct functional classification so this is actually special for endocrine tumours, the classification of the tumour depends as well on pathology as on the endocrinological information on functionality.
Why is classification important?
This is important because different neuroendocrine tumours have, first, a different prognosis, they can be very slow progressive, they can have a benign clinical course. On the other hand, they can be very aggressive and lead to the death of the patient in less than two years so the different subtypes are essential for the patient’s prognosis but also for the means of therapy that are selected.
Is there a tumour site where these are more prolific?
Most frequent clinically relevant neuroendocrine tumours arise in the GI tract, arise in the pancreas and the small intestines. but actually they can arise everywhere in the body.
Is any research being done into biomarkers?
Yes, there are different types of biomarkers. We have diagnostic biomarkers, which in the tissue is the synaptophysin and chromogranin, then we have prognostic biomarkers, the grading actually is done using a prognostic biomarker, Ki-67, and what we do not yet really have but what we need in the future is to have predictive biomarkers helping us to select patients for specific therapy regimens.
What are some of the research needs?
One of the problems hampering progress in neuroendocrine tumour treatment is that, first, they are a rare disease and, second, it’s not one disease but actually this rare disease is composed of several different, even rarer, diseases so to really get information about these subtypes networks are very important. There is, for example, the European Neuroendocrine Tumour Society which is an interdisciplinary network. Such networks need also to be constructed for tissue collections, for biobanks. It can be in the form of meta biobanks as in Switzerland, we have the meta biobank biobank-suisse which is trying to link the content of the different biobanks on an informatics level.
What research are you currently working on?
At the moment we are conducting studies on the genetic background of sporadic pancreatic endocrine tumours with the aim to maybe propose a genetically based sub-classification of these tumour types. Up to now there have been several attempts without big success to really be able to reproducibly sub-classify different nets according to gene expression signatures but maybe this will happen in the future.