Potential Biomarkers To Identify Benign Pancreatic Lesions

Highlights:

• It is difficult to distinguish between cancerous and non-cancerous variants of pancreatic cysts
• Two tests that assess the level of proteins VEGF-A and CEA have been found to be good indicators of cysts that are not cancerous
• These tests are potential biomarkers and can be used to limit the need for invasive diagnostic procedures

Pancreatic cancer is a cancer of the pancreas that is difficult to detect early. Pancreatic lesions or cysts develop within the pancreas, and while some cysts are non-inflammatory, others are inflammatory in nature. These cysts range in size from millimeters to several centimeters; some cysts may be small and benign without resulting in any symptom. However, some cysts are cancerous.

It has been difficult to distinguish between lesions that are cancerous and those that are benign, without invasive testing procedures. However, a recent study by a research team from Indiana University has found that when two laboratory tests are performed in tandem, pancreatic lesions that are benign, but which closely resemble pre-cancerous lesions, may be identified.

The study was published in the journal of the American College of Surgeons, and it is one of the largest studies conducted on pancreatic lesions.

• 2-3% of patients get detected with pancreatic lesions on a routine abdominal scan.

Most of these patients develop pancreatic cancer, especially the most severe form called pancreatic adenocarcinoma.

• The 5 year survival rate of these patients is
• 12-14% for those with early stage disease
• 1-3% for those with advanced stage of disease
• A small percentage of these patients detected with pancreatic lesion would have serious cystic neoplasms (SCN). These are non-malignant and do not develop into cancer.

Though people with SCN do not progress to cancer, they are often subjected to undergo imaging every 6 months in order to monitor the lesion. Sometimes, patients with these lesions are required to undergo surgical intervention as a precautionary measure to remove the lesions. Almost 60% of these patients are not predicted to be in the benign state till after the surgery. Radiological imaging has been found to miss nearly 50 to 70% of these lesions.

Potential Diagnostic Testing

The study by the research team from Indiana University has found that two proteins play an important role in determining if the lesions are pre-cancerous or cancerous.

• Vascular endothelial growth factor A (VEGF-A) is a protein that is found to be involved in the formation of new blood vessels. This protein's expression is increased in many different types of tumors and the research team from Indiana University has used this protein in its diagnostic test.
• Carcinoembryonic antigen (CEA) is a protein that is found to be involved in cell adhesion. This protein, while being present in low levels in healthy individuals, is found in increased levels in individuals with certain types of cancer.

Testing for the Proteins:

The level of these proteins is tested in pancreatic cyst fluid and the results of the findings are:

• Accurate identification of serious cystic neoplasm (SCN) from other types of pancreatic lesions.
• The levels of VEGF-A independently identified serious cystic neoplasms with a specificity of 83.7% and a sensitivity of 100%.
• The levels of CEA independently identified serious cystic neoplasms with a specificity of 81.5% and a sensitivity of 95.5 %.
• When the tests for the proteins were taken together, they reached the gold standard of pathologic testing. The combined specificity was 100% while sensitivity was 95.5%.
• In the study, the research team found that 26 patients could have been prevented from opting for surgery.

Pancreatic cysts have always worried patients as well as doctors, because of the unknown risk of these lesions developing into cancer. Most patients are subjected to surgery or invasive tests to ensure that these cysts are harmless and that they do not lead to cancer. Dr. C. Max Schmidt, MD, PhD, FACS, who is the study author and a professor of surgery and biochemical/molecular biology at Indiana University School of Medicine said that the test that involves both VEGF-A as well as CEA could be used to identify patients who do have the risk for cancer and hence avoid the need for surgery in them.

Developing a Diagnostic Technique:

149 study participants who had previously undergone a surgery to remove a pancreatic cyst were included in the study.

• Out of these, 26 participants had serious cystic neoplasm
• Pathological examinations were used to confirm the diagnosis

The samples of the pancreatic cyst fluid were used to detect the levels of VEGF-A and CEA, using enzyme linked biochemical assays.

Further research studies are required to confirm the accuracy of the VEGF-A and CEA levels and the risk of developing pancreatic cancer.

The research team stated that there was a need to carry out the test under stringent conditions, and specimens could be sent to Indiana University Health Pancreatic Cyst and Cancer Early Detection Center for analysis, if required.

There are many ongoing research studies being carried out to identify biological markers for pancreatic cancer. The current study focuses on differentiating between cysts that will not develop into cancer and cysts that would. This will help in reducing the number of people who would require invasive surgical procedures.

References :

1. Treatment & Support - (https://www.cancer.org/treatment.html)
2. Rosalie A. Carr, Michele T. Yip-Schneider, Scott Dolejs, Bradley A. Hancock, Huangbing Wu, Milan Radovich, C. Max Schmidt. Pancreatic Cyst Fluid Vascular Endothelial Growth Factor A and Carcinoembryonic Antigen: A Highly Accurate Test for the Diagnosis of Serous Cystic Neoplasm. Journal of the American College of Surgeons, 2017; 225 (1): 93 DOI: 10.1016/j.jamcollsurg.2017.05.003
3. General Information About Pancreatic Cancer - (https://www.cancer.gov/types/pancreatic/patient/pancreatic-treatment-pdq)

Source: Medindia