Neuroendocrine malignancies, are a type of cancer that develops in cells of the neuroendocrine system. The neuroendocrine system is made up of cells that produce hormones and neurotransmitters, and these cells are found throughout the body, including the lungs, gastrointestinal (GI) tract, pancreas, and other organs. They can be benign (non-cancerous) or malignant (cancerous). When they are malignant, they can be classified as either well-differentiated or poorly differentiated, depending on the degree of cell differentiation. Well-differentiated NETs are typically slow-growing and less aggressive, while poorly differentiated NETs are faster growing and more aggressive.
The GI neuroendocrine malignancies can be broadly classified as NETs and NECs.
| Characteristic | Neuroendocrine Tumor (NET) | Neuroendocrine Carcinoma (NEC) |
|---|---|---|
| Definition | A group of rare tumors that arise from cells in the endocrine and nervous system | A type of cancer that arises from neuroendocrine cells and has the ability to spread to other parts of the body |
| Grade | Typically divided into grades 1, 2, and 3, based on the tumor’s appearance and how quickly it is likely to grow | Generally considered high-grade tumors |
| Differentiation | Usually well-differentiated, meaning that the tumor cells look similar to normal cells, but they can be moderately differentiated, poorly-differentiated as well | Typically poorly differentiated, meaning that the tumor cells look very different from normal cells |
| PET scans | Positive uptake on Gallium/Copper dotatate scans (Octeroscans are not as sensitive, so not commonly used now) | often detected with FDG PET scans |
| Ki-67 | Typically low Ki-67 index (less than 20%) | High Ki-67 index (greater than 20%) |
| Mutations | Rarely associated with TP53 or RB1 mutations | More commonly associated with TP53 mutations and RB1 gene loss |
| Somatostatin receptors | NETs typically have more somatostatin receptors than NECs, and treated with octreotide (given IM, may need a trained professional) or lanreotide (given SQ) | NECs may have fewer somatostatin receptors and may be less responsive to somatostatin analogues |
| Functional vs. non-functional | NETs can be classified as functional (secrete serotonin, causing carcinoid syndrome) or non-functional tumors | NECs are generally non-functional tumors |
The Lung neuroendocrine tumors (NETs) are a type of cancer that originates in the neuroendocrine cells of the lungs. These tumors can be classified into three subtypes: typical carcinoid, atypical carcinoid, and poorly differentiated small/large cell lung cancer. The classification is based on mitotic index and the appearance of the tumor cells under the microscope and their behavior.
For optimal understanding and treatment of these tumors, it is crucial for patients to be evaluated by a physician who is experienced and knowledgeable in the diagnosis and management of neuroendocrine tumors and neuroendocrine carcinomas.
