BiliSeq identified approximately 82% of bile duct cancers in a six-year, multi-institutional study, compared to 44% with pathology alone.
A molecular test developed at UPMC Hillman Cancer Center and the University of Pittsburgh School of Medicine detected bile duct cancer at roughly twice the rate of standard pathology, offering clinicians a more accurate diagnostic tool for one of oncology’s more elusive malignancies.
The test, called BiliSeq, was evaluated in a prospective, multi-institutional study published in Gastroenterology, the flagship journal of the American Gastroenterological Association. Over six years, researchers analyzed nearly 3,000 bile duct specimens from more than 2,000 patients across the United States.
BiliSeq identified approximately 82% of bile duct cancers, compared to 44% with pathology alone. When combined with standard pathology, cancer detection rose to nearly 90%, with a low rate of misclassifying benign disease as malignant.
Why Standard Testing Falls Short
Bile duct cancers—also known as cholangiocarcinomas—are difficult to diagnose because tumors are often small, hard to reach, and surrounded by inflammation or scar tissue. Traditional biopsy and cytology methods frequently fail to yield a clear diagnosis, leaving patients and physicians in a prolonged state of uncertainty.
“For decades, in bile duct cancer we’ve known that a negative biopsy doesn’t always rule out cancer,” says Adam Slivka, MD, PhD, professor of medicine in the Division of Gastroenterology, Hepatology and Nutrition at the University of Pittsburgh School of Medicine and director of the gastroenterology service line at UPMC, in a release. “That uncertainty drives repeat testing and sometimes surgery without clear answers.”
BiliSeq addresses this diagnostic gap by detecting genetic mutations associated with cancer in bile duct tissue. Unlike traditional pathology, the test functions even when tumor cells are sparse, damaged, or indistinguishable from surrounding inflammation under the microscope.
Beyond Diagnosis: Treatment-Relevant Genetic Insights
One of BiliSeq’s key advantages is that it provides more than a binary cancer-or-no-cancer result. In the study, the test identified treatment-relevant genetic information in approximately one in five patients. In nearly one-third of those cases, that information led to a change in how care was managed.
“That’s where this really becomes personalized medicine,” says Slivka in a release.
Beyond informing systemic treatment decisions, BiliSeq results are already being used alongside standard clinical evaluation to help guide liver transplant decision-making in select patients at UPMC.
Performance in High-Risk Populations
The study also examined BiliSeq’s performance in high-risk patient groups, including those with primary sclerosing cholangitis and Hispanic patients—populations in which pathology alone missed up to half of cancers. When BiliSeq was combined with standard pathology in these groups, clinicians were able to identify up to 86% of cancer cases.
The large, prospective, multi-institutional design was intended to reflect real-world clinical practice rather than controlled laboratory conditions. “We receive and analyze samples from patients at medical centers across the country,” says Slivka in a release. “For these patients, BiliSeq means less testing, less waiting and more options.”
BiliSeq is not a general population screening tool. It is intended for use in patients who already present with bile duct narrowing or obstructions requiring a clearer diagnosis.
The study builds on a broader effort by Pitt and UPMC researchers to develop molecular diagnostics for gastrointestinal cancers, including prior work in pancreatic cancer and pre-cancerous cysts. The research was supported in part by the National Institutes of Health, the Western PA Chapter of the National Pancreas Foundation, the Sky Foundation, and the Pancreatic Cancer Action Network.
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