Using blood samples of pancreatic cancer and chronic pancreatitis patients, researchers in Japan have developed a metabolomics-based test that may be an easy and noninvasive way to detect pancreatic cancer.
CT scans of the pancreas demonstrating a mass in the pancreatic tail and metastases in the spleen; source: Rong Y, Lou W, Jin D, Wikimedia Commons
Researchers have developed a metabolomics-based test that may be an easy and noninvasive way to detect pancreatic cancer. Masaru Yoshida, MD, PhD, chief of the division of metabolomics research at Kobe University Graduate School of Medicine in Kobe, Japan and colleagues analyzed blood samples of pancreatic cancer and chronic pancreatitis patients as well as healthy volunteers to develop a panel of 18 metabolites whose levels are significantly different in healthy volunteers compared with pancreatic cancer patients. The test shows both high sensitivity and specificity, according to the researchers. The development and validation approach is published today in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.
Pancreatic cancer is typically characterized by rapid progression from early-stage disease to metastasis. The cancer is typically diagnosed late due to a lack of efficient early screening methods and lack of distinct pancreatic cancer-specific symptoms. As one of the leading causes of cancer-related deaths with a less than 5% survival rate at 5 years, accurate earlier detection methods are needed. Surgical tumor removal provides a chance for a cure, but because of late detection, as many as 80% of patients with pancreatic cancer have unresectable and incurable disease.
Current screening and biomarker methods are not enough to detect pancreatic cancer early. Imaging is not cost-effective and cannot differentiate well between pancreatic tumors and benign pancreatic disease. The tumor marker CA19-9 is typically used but is inefficient during early-stage disease and is not unique to pancreatic cancer, resulting in a relatively high false positive rate.
“Conventional examinations using blood, imaging, and endoscopy are not appropriate for pancreatic cancer screening and early detection, so a novel screening and diagnostic method for pancreatic cancer is urgently required,” said Yoshida in a press release.
Aiming for a safe, convenient, and accurate way to test for pancreatic cancer, Yoshida and colleagues analyzed the low molecular weight metabolite components of blood to develop a panel of metabolites with distinct levels in both healthy individuals and pancreatic cancer patients. The researchers used gas chromatography mass spectrometry to measure and compare the levels of metabolites in the blood of healthy individuals, those with pancreatic cancer, and those with pancreatitis. Samples from 42 pancreatic cancer patients, 41 healthy volunteers, and 23 chronic pancreatitis patients were used in a validation set after identification of the metabolite panel. Chronic pancreatitis patients were included because, like pancreatic cancer, it is associated with a high level of chronic inflammation. Differentiating between chronic pancreatitis and pancreatic cancer remains a major challenge of diagnosis.
The researchers also developed a way to predict the diagnosis of pancreatic cancer using four of the metabolites in the panel. This method showed 86% sensitivity and 88.1% specificity in a training set and 71.4% sensitivity and 78.1% specificity in a validation data set. “Our diagnostic approach using serum metabolomics possessed higher accuracy than conventional tumor markers, especially at detecting the patients with pancreatic cancer in the cohort that included the patients with chronic pancreatitis,” said Yoshida said.
Further testing using patient samples from multiple centers in a large-scale trial is necessary to further validate the new screening method. The authors believe that after this large validation trial, the test will be a reliable and safe way to screen for pancreatic cancer when the disease is still resectable and curable.