Neuroendocrine gut and pancreatic
tumors are rather rare malignant diseases which has gained increased attraction through the last decennium, possibly through development of new diagnostic and therapeutic methods. Histopathology demonstrating the common neuroendocrine features of these
tumors has been the diagnostic corner stone for long, but today it should be supplemented with information about the
tumor biology. An excellent
biochemical marker which is easy to analyze in serum or plasma is
chromogranin A, which is a
glycoprotein that is stored and released from neuroendocrine cells. This marker can be used for diagnosis and follow-up of the patients.
Somatostatin receptor scintigraphy has been one of the most important diagnostic tools for staging of the disease and also indicating sensitivity to treatment with
somatostatin analogues. It is a general agreement that almost every patient should be subjected to this procedure before or during the treatment course. From the therapeutic point of view, surgery is nowadays more extensive aiming at reducing the
tumor mass in patients who could not be cured by surgery alone. Other means of
tumor reduction is liver dearterialization by embolization with
starch spheres. The medical treatment of
neuroendocrine tumors has made a real break through with the introduction of
somatostatin analogues, particularly
octreotide, and today most of the hormonally related symptoms can be controlled by this kind of treatment.
Somatostatin analogues have also shown to be inhibitors of
tumor growth and the latest development is
tumor targeted radioactive treatment with Ytrium or
Indium labelled
octreotide. Long-acting formulation of
somatostatin analogues have come into clinical use and significantly improved quality of life for patients with
neuroendocrine tumors. Other means of medical treatment are alpha
interferons, which have shown particular effect in patients with midgut
carcinoid tumors giving both biochemical and
tumor responses.
Chemotherapy such as
streptozotocin plus
5-fluorouracil (5-FU) or
doxorubicin is still considered as first-line treatment in malignant endocrine pancreatic
tumors but is combined with concomitant
somatostatin analogue treatment. In the future a
multimodal treatment will further develop combining different agents and also
somatostatin receptor subtype specific analogues will come into clinical use.