Blood Test May Aid Detection Of Multiple Cancer Types

A blood test in development that uses targeted methylation analysis of cell-free DNA can aid in the early detection of multiple cancer types that are hard to detect, including gastrointestinal (GI) cancers, according to new research.

"The potential of this test is to diagnose cancer earlier, when it's more treatable. The ability to do that across cancer types could be quite valuable," lead investigator Dr. Brian Wolpin, of Dana-Farber Cancer Institute in Boston, said in a press release from the American Society of Clinical Oncology (ASCO). "Many of the cancer types that this test detects don't currently have screening tests that allow earlier cancer detection before the cancers cause symptoms."

The test is being developed by GRAIL, Inc, which funded study. "These results support GRAIL's ongoing efforts to bring our multi-cancer early detection test into the clinic to begin returning results to patients and providers this year," a representative from the company said in a statement emailed to Reuters Health.

At the 2020 Gastrointestinal Cancers Symposium, which took place last week in San Francisco, Dr. Wolpin reported on the blood test's performance for various GI cancers including 67 patients with esophagus/stomach cancer, 95 with pancreas/gallbladder/extrahepatic bile duct cancer, 29 with liver/intrahepatic bile duct cancer and 121 with cancer of the colon/rectum.

The patients are part of the Circulating Cell-free Genome Atlas (CCGA) study, an ongoing, prospective, observational study that is following people with more than 20 types of cancer and people without cancer.

Across all GI cancers, the test had an overall sensitivity of 82% for cancer detection in the training set and 81% in the validation set, with a specificity topping 99%, Dr. Wolpin reported. The overall accuracy for defining the GI tissue of origin was 91% and 89%, respectively.

"The data show that evaluating methylation of cell-free DNA within a blood sample may detect a variety of gastrointestinal cancers with good sensitivity and with a low rate of false positives. If further validated with additional testing, this approach has the potential to allow us to diagnose gastrointestinal cancers earlier, when they're more treatable," Dr. Wolpin said in the release.

Commenting on the results in the same release, ASCO expert Dr. Muhammad Shaalan Beg said, "Blood tests that can identify cancer in asymptomatic individuals, particularly GI cancers that can be difficult to detect in early stages, could change cancer diagnostics by making it easier to accurately screen for and identify these cancers earlier. The preliminary results seen in this study, however, will need to be validated by screening large populations of asymptomatic individuals."

GRAIL is conducting two large population-based studies to further investigate the potential of the screening blood test. One called, STRIVE, has already enrolled almost 100,000 women undergoing screening mammograms. The other known as SUMMIT is in the process of enrolling 50,000 men and women without a known diagnosis of cancer.

Dr. Wolpin and several co-investigators have financial relationships with the company.

—Megan Brooks

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