Neuroendocrine Tumor: Diagnosis, Symptoms, Treatment ...

What is a neuroendocrine tumor (NET)?

Neuroendocrine tumors are a group of uncommon tumors that start in specialized cells in your neuroendocrine system. These cells combine the traits of nerve cells and hormone-producing endocrine cells. They link your endocrine system, which manages your hormones, and your nervous system. Neuroendocrine cells are scattered throughout your body.

NET has several types and sub-types with symptoms that might be mistaken for other less serious conditions. Once considered a rare cancer, more and more people are being diagnosed with NET thanks to improved diagnostic tests that identify NET more quickly. Early diagnosis and treatment continues to increase the number of people living for years with NET.

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How do neuroendocrine cells work?

Neuroendocrine cells act like traffic cops monitoring busy intersections and telling drivers when to stop and go. Like them, your endocrine cells monitor signals from your nervous system. When they get the signal, your cells tell your endocrine system to release hormones. Hormones are chemicals that coordinate different body functions, let your body know what to do and when to do it.

But your neuroendocrine cells do more than watch signals and trigger hormone flow. They also make and release hormones that control activity in the organ where they’re located. For example, the neuroendocrine cells in your gut (digestive system) make hormones that drive production of digestive juices and coordinate the muscles that move food through your bowels.

Neuroendocrine tumors happen when your endocrine cells begin to divide and multiply uncontrollably, eventually becoming tumors that can affect the organs where the cells are located.

What are the different types of neuroendocrine tumors?

Neuroendocrine tumors are classified as primary or secondary tumors. A primary tumor is cancer that hasn’t spread to other areas of your body. A secondary tumor is a NET that has spread, usually to your lymph nodes in your lymphatic system, your liver or your bones.

NET types are based on their location. For example, a neuroendocrine tumor in your gut is a neuroendocrine tumor of the gastrointestinal tract. Here are the most common primary neuroendocrine tumor types:

• Gastrointestinal (GI) tract. NETs develop most commonly in the GI tract, specifically in the large intestine (20%), small intestine (19%), and appendix (4%). The GI tract plays a central role in digesting foods and liquid and in processing waste. GI tract NETs used to be called carcinoid tumors.
• Lung. The lung is the second most common location of NETs. About 30% of NETs occur in the bronchial system, which carries air to the lungs. Lung NETs also used to be called carcinoid tumors.
• Pancreas. Approximately 7% of NETs can develop in the pancreas, a pear-shaped gland located in your abdomen between the stomach and the spine. Pancreatic NETs (PNETS), which used be called islet cell tumors, represent about 7% of all pancreatic cancers.

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Who do these tumors affect?

Almost anyone can develop neuroendocrine tumors, including children, but NETs are very rarely seen in children, teenagers and young adults. The average age at diagnosis is between ages 50 to 60. Females are slightly more likely than males to develop neuroendocrine tumors.

How common is this condition?

Neuroendocrine tumors affect about 5 in 100,000 people. More than 12,000 new cases are diagnosed each year and as many as 125,000 people with these tumors are living in the U.S. today.

.NET Framework FAQ

What is .NET Framework used for?

.NET Framework is used to create and run software applications. .NET apps can run on many operating systems, using different implementations of .NET. .NET Framework is used for running .NET apps on Windows.

Who uses .NET Framework?

Software developers and the users of their applications both use .NET Framework:

• Users of applications built with the .NET Framework need to have .NET Framework installed. In most cases, .NET Framework is already installed with Windows. If needed, you can download .NET Framework.
• Software developers use .NET Framework to build many different types of applications—websites, services, desktop apps, and more with Visual Studio. Visual Studio is an integrated development environment (IDE) that provides development productivity tools and debugging capabilities. See the .NET customer showcase for examples of what people are building with .NET.

Why do I need .NET Framework?

You need .NET Framework installed to run applications on Windows that were created using .NET Framework. It's already included in many versions of Windows. You only need to download and install .NET Framework if prompted to do so.

How does .NET Framework work?

.NET Framework applications are written in C#, F#, or Visual Basic and compiled to Common Intermediate Language (CIL). The Common Language Runtime (CLR) runs .NET applications on a given machine, converting the CIL to machine code. See Architecture of .NET Framework for more info.

What are the main components/features of .NET Framework?

The two major components of .NET Framework are the Common Language Runtime (CLR) and the .NET Framework Class Library. The CLR is the execution engine that handles running applications. The Class Library provides a set of APIs and types for common functionality. See Architecture of .NET Framework for more info.

What is the difference between .NET and .NET Framework?

.NET and .NET Framework share many of the same components and you can share code across the two. Some key differences include:

• .NET is cross-platform and runs on Linux, macOS, and Windows. .NET Framework only runs on Windows.
• .NET is open-source and accepts contributions from the community. The .NET Framework source code is available but doesn't take direct contributions.
• All of the innovation happens in .NET.
• .NET Framework is included in Windows and automatically updated machine-wide by Windows Update. .NET is shipped independently.

See .NET vs. .NET Framework for server apps for more details.

Can you have multiple .NET Frameworks installed?

Some versions of .NET Framework are installed side-by-side, while others will upgrade an existing version (known as an in-place update). In-place updates occur when two .NET Framework versions share the same CLR version.

For example, installing .NET Framework 4.8 on a machine with .NET Framework 4.7.2 and 3.5 installed will perform an in-place update of the 4.7.2 installation and leave 3.5 installed separately.

How much does .NET Framework cost?

.NET Framework is free, like the rest of the .NET platform. There are no fees or licensing costs, including for commercial use. See .NET is free for more details.

Which version of .NET Framework should I use?

In most cases, you should use the latest stable release. Currently, that's .NET Framework 4.8.1 .

Applications that were created with any 4.x version of .NET Framework will run on .NET Framework 4.8.1 . To run an application that was created for an earlier version (for example, .NET Framework 3.5), you should install that version. See Download .NET Framework for a complete list.

What is the support policy for .NET Framework?

.NET Framework 4.8.1 is the latest version of .NET Framework and will continue to be distributed with future releases of Windows. As long as it is installed on a supported version of Windows, .NET Framework 4.8.1 will continue to also be supported.

See the .NET Framework support policy for more details