Neuron-specific enolase (NSE)
Why this test?
For the diagnosis of small cell lung cancer, making its prognosis and monitoring its treatment.
For the diagnosis of pheochromocytoma.
For the diagnosis of medullary cancer of the thyroid gland.
For the diagnosis of neuroendocrine tumors of the gastrointestinal tract.
For the diagnosis and prognosis of neuroblastoma.
For making a prognosis in case of traumatic and hypoxic brain damage.
In what cases is it prescribed?
With symptoms of small cell cancer: unmotivated weakness, weight loss, cough and hemoptysis, shortness of breath, pathological fractures and characteristic paraneoplastic syndromes, especially in smokers.
When planning chemotherapy and evaluating its results, as well as when making a prognosis for small cell lung cancer.
With symptoms of pheochromocytoma in adults: arterial hypertension (diastolic), especially during the crisis course of the disease, which is accompanied by a throbbing headache, rapid heartbeat, increased sweating, excitement.
With symptoms of medullary thyroid cancer: tightness in the neck, painless regional lymphadenitis, prolonged diarrhea.
With hyperinsulinemia, hypergastrinemia, hyperglucagonemia.
With symptoms of neuroblastoma in children: with pain in the bones, in the stomach, with lameness, nausea, loss of appetite and weight, hemorrhages on the skin around the eyes, diarrhea.
With a hereditary predisposition to multiple endocrine neoplasia syndromes.
With brain injuries and cerebral coma, ischemic stroke and cerebral anoxia.
When making a prognosis for a patient with traumatic and hypoxic brain damage.
Neuron-specific enolase (NSE) is one of the structural variants of the enzyme enolase, which is required for glycolysis and is therefore present in all cells of the body. Isoforms of this enzyme are tissue-specific. Neuron-specific enolase, NSE, is an isoform characteristic of neurons, with some structural features necessary for the normal functioning of this enzyme at elevated concentrations of chlorine ions. In addition to the cytoplasm of neurons, NSE is also found in cells of neuroendocrine origin, such as chromaffin cells of the medulla of the adrenal glands, parafollicular cells of the thyroid gland, and some others. However, increased synthesis of this enzyme occurs in tumor cells, which ensures a high rate of glycolysis, active growth of the tumor and its spread to the surrounding tissues. An increase in NSE is often observed in small cell lung cancer, as well as in medullary thyroid cancer, pheochromocytoma, neuroendocrine tumors of the intestine and pancreas, and neuroblastoma.
Small cell lung cancer is an anaplastic process and has neuroendocrine properties. For example, this type of cancer is characterized by the secretion of adrenocorticotropic hormone (ACTH), antidiuretic hormone (ADH), as well as neuron-specific enolase. Such features determine the clinical picture of the disease, and can also be used for its diagnosis. A high level of NSE is an unfavorable prognostic factor and is associated with insufficient tumor response to chemotherapy, rapid disease progression, and a high probability of death. Therefore, the measurement of NSE concentration can be used to make a prediction. A decrease in the level of NSE during treatment is associated with a slower progression of the tumor, which allows the use of this tumor marker to evaluate the results of the treatment.
Other types of lung cancer are united under the general name non-small cell lung cancer. This group of diseases, unlike small cell cancer, does not have neuroendocrine properties, and it is not characterized by the production of excessive amounts of NSE. Therefore, NSE can be used for the differential diagnosis of small cell and non-small cell lung cancer. This laboratory indicator is especially useful when routine diagnostic methods cannot be performed due to the severity of the disease or concomitant pathology.
Adrenal medulla cells, parafollicular cells of the thyroid gland, and neuroendocrine cells of the gastrointestinal tract share a common origin from the neural crest. Tumors from these cells are characterized by increased secretion of specific hormones (adrenaline in pheochromocytoma, calcitonin in medullary thyroid cancer), as well as excessive production of neuron-specific markers, including NSE. Therefore, NSE measurement can be performed in the diagnosis of pheochromocytoma, medullary thyroid cancer, gastrinoma and insulinoma, as well as carcinoid tumors of the gastrointestinal tract. The common origin of these cells also explains the phenomenon of the combination of several tumors of different localization in the same patient.
While the most common adrenal medulla tumor in adults is pheochromocytoma, the most common in children is neuroblastoma, a malignant tumor that also originates from neural crest neuroblasts and is capable of producing catecholamines and NSE (most patients are less than 2 years old at diagnosis). The clinical picture is due to tumor compression of neighboring structures and an excess of adrenaline and dopamine. A high level of NSE in neuroblastoma is an unfavorable prognostic sign.
Normally, NSE is present in large quantities in neurons of the central and peripheral nervous system. Its concentration increases significantly when nerve tissue is damaged as a result of mechanical brain injury or hypoxia. The increased level of NSE is associated with the size of the brain contusion site and the presence of subarachnoid hemorrhage. In addition, it is an unfavorable prognostic factor in a patient with a traumatic brain injury. This indicator can be used together with instrumental methods when making a decision to stop providing medical care. The concentration of NSE increases in ischemic stroke, and its high growth rate is associated with an unfavorable prognosis of the disease. This clinical and laboratory indicator can also be used to assess the degree of brain damage in anoxia caused by cardiac arrest.