Neuroendocrine tumors can hide behind the symptoms of other diseases - Dr. Kust for Miss Zdrava

Neuroendocrine tumors (NETs) are a specific group of tumors that arise from so-called neuroendocrine cells. One of the functions of these cells is to release hormones into the blood in response to signals from the nervous system. Such cells are found in the endocrine glands of the body, but also in virtually all other tissues, so neuroendocrine tumors can arise anywhere in the body. For this reason, they are listed collectively, rather than by the site of origin like most other tumors (e.g. pancreatic cancer). They most often arise in the digestive system, primarily in the small intestine and pancreas, followed by lung NETs.

They are generally considered rare tumors, with an estimated annual incidence of around 2.5 - 5 per 100,000, but it should be emphasized that their incidence in the world is constantly and significantly increasing. This seems to be largely due to increasingly precise diagnostics. Namely, neuroendocrine tumors are a diverse group of tumors when we look at their aggressiveness, making a spectrum from almost benign formations to extremely aggressive tumors. A significant part of neuroendocrine tumors with a good prognosis are discovered by chance during medical examinations for other diseases or during systematic examinations because they do not cause any symptoms and people with them can live and die without knowing that they have them.

Symptoms are also caused by hormones secreted by the tumors

Some of the symptoms of NETs can follow the place where they arise, so for example, aggressive neuroendocrine tumors of the lungs can behave like other (typical) lung tumors due to pressure and ingrowth into surrounding structures and organs. However, given their ability to secrete hormones, NETs can also give some specific symptoms.

For example, pheochromocytomas, NETs of the adrenal cortex, can cause an increase in blood pressure due to the secretion of catecholamines, while insulinomas of the pancreas can lead to low blood sugar levels (hypoglycemia) due to the secretion of insulin. In addition to the specific hormones secreted by neuroendocrine cells in various parts of the body, many of them also have common (non-specific) hormones and active substances that they can secrete. For example, many of them can secrete serotonin, which can lead to the so-called carcinoid syndrome, which is characterized by redness, diarrhea, asthma, abdominal cramps, and over time can lead to damage to heart valves and heart failure.

The path to diagnosis is similar to that of other tumors, but treatment is complex

Diagnosing NETs does not differ significantly from the procedure used to detect any other type of tumor in the organ or tissue being investigated. For example, the procedure for detecting NETs in the small intestine does not differ significantly from the procedure used to diagnose any other tumor in the small intestine. As a rule, a biopsy (tissue sample) is required before treatment, from which the degree of aggressiveness of the disease can also be estimated based on the Ki-67 index. In addition to standard imaging tests, somatostatin receptor scintigraphy (tektrotide scintigraphy) or PET with Ga-68 are also very important in patients with NETs, ​​which examine the presence of receptors for the hormone somatostatin on tumor cells, which is important in the decision on treatment.

The treatment of NETs is very complex and requires significant clinical experience, given that these are rare tumors. As a rule, in the phase of localized disease (without distant metastases), local treatment methods are preferred, primarily surgical treatment. In the phase of metastatic disease, treatment depends significantly on the degree of tumor differentiation (grade). In patients with lower grades (1 and 2), in the case of a positive tektrotide scintigraphy finding, somatostatin analogues are most often the first choice of treatment. In these patients, the use of peptide receptor radionuclide therapy (PRRT), chemotherapy and targeted therapy are also options during treatment. For high-grade patients, the main choice of treatment is chemotherapy.

Regular check-ups are the key to a positive treatment outcome

The prognosis directly depends on the stage of the disease at diagnosis and the aggressiveness of the tumor, or grade. We can say that in localized low-grade tumors, the cure rate is practically 100%, while in very aggressive variants of NET in the stage of widespread disease, it is difficult to expect a cure. Regular check-ups are important so that if the disease occurs, it can be detected as early as possible, which significantly increases the patient's chances of a positive treatment outcome.

Healthy lifestyle habits are the best prevention

Currently, we do not know enough about the cause of neuroendocrine tumors. Most NETs appear sporadically, i.e. without a clear cause, and the risk factors for the development of this disease are poorly known. Some NETs occur as part of hereditary genetic syndromes, such as MEN1, MEN2, von Hippel-Lindau disease and neurofibromatosis. The general recommendations that I give as an oncologist for the purpose of prevention to all people are not smoking, moderate alcohol consumption, maintaining an adequate body weight, engaging in regular physical activity and eating a healthy and varied diet.

The complete article published on the Miss Zdrava portal can be found at the link.