The most common sites of origin of these tumors are the digestive tract, the pancreas and the lungs. Some of these tumors produce hormones, which can lead to pronounced symptoms and complaints in those affected. Overall, these are rare diseases, which is why a team of experts with experience in this field is very important for successful treatment. We were certified as the first Swiss Center of Excellence for neuroendocrine tumors back in 2013 and have a corresponding wealth of experience.
The choice of therapy for endocrine neoplasia depends crucially on the growth rate of the tumors. The pathologist determines the growth rate using a tumor tissue sample. The tumors are divided into NET G1, NET G2, NET G3 and NECs depending on their growth rate, with NETs G1 generally corresponding to very slow-growing tumors and NECs to extremely fast-growing tumors. For slow-growing neuroendocrine neoplasias, well-tolerated hormone therapy is often used initially. The faster the tumor cells divide, the more important chemotherapy can be for treatment. A large proportion of these tumors can also be treated very effectively with nuclear medicine therapy (PRRT, link). Molecularly targeted therapies and, in some cases, cancer immunotherapy are also available. All treatment recommendations are made in our interdisciplinary special tumor conference and reviewed on a regular basis.
Hormone therapy for NETs
Slow-growing neuroendocrine tumors with or without hormone production can be treated well with hormone therapy. For this purpose, patients receive injections of a long-acting somatostatin preparation at 4-week intervals. Somatostatin is a hormone produced naturally in the body that influences digestive processes. Neuroendocrine tumor cells very frequently carry somatostatin receptors on their surfaces. The therapeutic administration of somatostatin inhibits the release of hormones from tumor cells and thus reduces disease symptoms triggered by hormone-producing NETs. These include flushing, diarrhea and palpitations. A variety of other complaints are possible, depending on the hormones released.
However, hormone therapy with somatostatin also inhibits the growth of these tumors. This brings tumor growth to a standstill, sometimes the tumors shrink.
Somatostatin therapy is generally well tolerated; mild digestive disorders are the most common side effects. Even in long-term treatment over several years, these therapies are mild and usually well tolerated.
The response is checked regularly by imaging. In order to be effective, somatostatin receptors must be detectable on the tumor cell surface. This is checked by so-called functional imaging (GA-DOTATATE-PET/CT) before the start of therapy.
Chemotherapy for NETs and NECs
Chemotherapy can also be very effective for neuroendocrine neoplasia, depending on the rate of growth and the site of origin of the tumors. Slow- and medium-growing nets are typically treated with a combination of chemotherapy tablets. The so-called CAPTEM protocol is often used, which corresponds to a combination of capecitabine and temozolomide tablets. The side effects are typically mild to moderate, with blood count changes and mild nausea being the most common undesirable side effects.
Faster growing neuroendocrine neoplasms are treated with infusion chemotherapy. Your supervising doctor will inform you in detail about these protocols, their composition, administration and the expected side effects.
Molecularly targeted therapy and immunotherapy
Neuroendocrine tumors can also be treated with molecular therapies. These are administered in tablet form. Typical preparations are everolimus or sunitinib. Although these are modern and expensive cancer drugs, the treatment is often associated with relevant side effects. Loss of appetite, taste and digestive disorders and pronounced tiredness are quite common. We will also inform you in detail about this treatment.
Cancer immunotherapies, which are drugs that sensitize and activate the body’s own immune system against tumour cells, have so far been used relatively rarely in neuroendocrine neoplasia. Studies carried out have shown a rather limited efficacy of these substances in these tumors. Here too, we will advise you in detail about the cases in which immunotherapy can be useful and effective and what side effects can be expected
Precision medicine for neuroendocrine tumors
At the USZ, we consistently carry out advanced molecular diagnostics for medium-fast and rapidly growing neuroendocrine neoplasias. This makes it possible to detect molecular tumor changes that can be used therapeutically in some cases. We discuss the findings of these examinations in a special conference, our molecular tumor board. If molecular diagnostics reveal additional treatment options, we carry out personalized therapies adapted to the molecular changes.
