Blood Test for Cancer Hits Roadblock

A Blood Test for Early Cancer Detection Sparks Debate

A new ‘liquid biopsy’ detects bits of DNA common in several cancers, though critics question its value

Scientists have long dreamed of spotting cancers with a simple blood test in people who haven't shown symptoms.

One company says that day is here—though it has yet to convince government regulators.

Pathway Genomics began marketing a blood test in mid-September that it says can detect DNA fragments linked to 10 common cancers in otherwise healthy people. Consumers can order the test directly from the company’s website by consulting with Pathway physicians and completing a questionnaire.

But many cancer experts—and competitors—say the Pathway test is far from scientifically proven and could cause unnecessary alarm.

“This test is essentially telling you, ‘You’ve got cancer!’ But it can’t be linked to a particular site in the body or tell you whether the cancer may be problematic now or in the future,” says J. Leonard Lichtenfeld, deputy chief medical officer of the American Cancer Society.

The Food and Drug Administration has raised concerns, too. The agency sent a letter to Pathway’s CEO last week saying: “We believe you are offering a high risk test that has not received adequate clinical validation and may harm the public health.”