the most common type of pancreatic cancer.
It is quite encouraging to know we have a blood test that could potentially find this disease early, said Ajay Goel, PhD, a molecular diagnostics specialist at City of Hope in Duarte, California, who presented the findings at the annual meeting of the American Association for Cancer Research (AACR).
Dr. Goel and colleagues developed a signature for pancreatic cancer based on microRNAs identified in the exomes shed from pancreatic cancers and cell-free DNA markers found in the blood of patients with the disease.
Their initial assay tested blood samples for this signature in a training cohort of 252 people in Japan, approximately 60% of whom had pancreatic cancer. The rest were healthy controls. The assay was then tested in validation cohorts of 400 subjects, half with pancreatic cancer and half controls, in China and South Korea.
In both the initial and validation tests, the microRNA assay had an accuracy of about 90% for stage I/II pancreatic cancer, already far better than commercially available assays.
In an additional validation cohort in the United States with 139 patients with pancreatic cancer and 193 controls at six centers across the country, the researchers found that adding carbohydrate antigen 19-9 — a well-known marker of pancreatic cancer — to the assay boosted the test’s accuracy to 97%.
The test performed the same whether the tumor was in the head or tail of the pancreas.
“We are very excited about this data,” said Dr. Goel.
The technology was recently licensed to Pharus Diagnostics for commercial development, which will likely include a prospective screening trial, he told this news organization.
Because pancreatic cancer is fairly uncommon, Dr. Goel did not anticipate the test being used for general screening but rather for screening high-risk patients such as those with newly diagnosed type 2 diabetes, a family history of pancreatic cancer, or predisposing genetic mutations.
“It should be a very inexpensive test; it doesn’t cost us much to do in the lab,” he added.
Study moderator Ryan Corcoran, MD, PhD, a gastrointestinal (GI) oncologist at Massachusetts General Hospital, Boston, saw the potential.
“As a GI oncologist, I know how lethal and hard to treat pancreatic cancer is,” he said. A test that could reliably detect pancreatic cancer early, with an acceptable false-positive rate, would be extremely useful.
“The cure rate is many, many times higher,” if we detect it before it has a chance to spread, he explained.
In the meantime, Dr. Goel said there’s more work to be done.
Almost 4,000 subjects have been enrolled in ongoing validation efforts, and efforts are underway to use the test to screen thousands of banked blood samples from the PLCO, a prospective cancer screening trial in healthy subjects.
The researchers also want to see if the test can distinguish benign pancreatic cysts from ones that turn cancerous.
The idea is to find the earliest possible signs of this disease to see if we can find it not “at the moment of clinical diagnosis, but possibly 6 months, 1 year, 2 years earlier” than with radiologic imaging, Dr. Goel said.
The work was funded by the National Cancer Institute and others. Dr. Goel is a consultant for Pharus Diagnostics and Cellomics. Dr. Corcoran is a consultant for, has grants from, and/or holds stock in numerous companies, including Pfizer, Novartis, Eli Lilly, and Revolution Medicines.
A version of this article appeared on Medscape.com.
