There are a number of ways that patients suffering with neuroendocrine tumors and cancer have their disease diagnosed and monitored.
The standard marker for neuroendocrine tumors is chromagranin A (sometimes abbreviated Cga). But there are a number of other markers that true neuroendocrine specialists use to help determine disease progression. These tests are things like:
In the case of pancreatic neuroendocrine primaries, tests could include:
- Vasoactive Intestinal Peptide (often just called VIP)
- Pancreatic Polypeptide
For a full list of the types of bloodwork associated with neuroendocrine tumors, please visit the Interscience Institute website. This lab specialized in bloodwork for neuroendocrine tumors and has many assays available.
CT (Computerized Tomography)
Considered the gold standard for monitoring disease, the CT is usually done as a triple phase scan showing both the arterial and venous phases. Usually, these scans are done with both an IV contrast and a liquid contrast that is consumed by the patient prior to the scan. This is an excellent run down on the CT scan and it’s phases.
MRI (Magnetic Resonance Imaging)
Excellent for imaging liver metastasis, Magnetic Resonance Imaging is commonly used to determine tumor burden in the liver and is superior to the CT, particularly in solid organs.
Octreoscan (Octreotide Scan)
This is the old workhorse scan for neuroendocrine tumors. While not the most sensitive in terms of being able to measure tumor size, it was able to detect tumors for people who had the type 2 receptors required by octreotide that was radiolabled with
Gallium 68 PET/CT
Just approved on June 1 for the detection of neuroendocrine tumors, this scan can have a higher sensitivity than the octreoscan for finding tumors. NETs have receptors for somatostatin, a hormone that regulates the endocrine system. Ga 68 dotatate, a positron emitting analogue of somatostatin, works by binding to such receptors. Even though approved, it will take some time before these types of scans are readily available in all markets. Also, be aware of the known false positives that can occur with pancreatic neuroendocrine tumors.
A biopsy is the removal of a small amount of tissue for examination under a microscope. This type of test can be done through a needle biopsy either percutaneously, by endoscope or if a growth has been surgically removed. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis. A biopsied neuroendocrine tumor can be tested for its proliferation rate known as a ki-67. Ki-67 can be controversial in terms of where the tumor is resected and the amount of cells in that area, but it is a generally good marker to indicate how quickly your disease is progressing.