Testing company wrongly tells more than 400 people they likely have cancer

More than 400 people who signed up for a pioneering early-warning cancer test were mistakenly told they likely had the disease, according to the testing company.

Grail Inc. confirmed that alarming letters were sent to patients in tryouts for its flagship test Galleri, which has been hailed as “revolutionary” in detecting more than 50 types of cancer before symptoms appear.

The warnings were sent to 408 people who signed up for the trial testing — half of whom had yet to even have their blood drawn, according to documents seen by the Financial Times.

Grail blamed a “software configuration issue” by its telemedicine vendor, PWNHealth, for the misfired letters that claimed to have detected a signal in the blood suggesting the presence of cancer.

Grail, owned by the world’s biggest gene sequencing company, Illumina, said the software mishap had been resolved and “was in no way related to or caused by an incorrect Galleri test result.”

PWNHealth told the FT that it launched an investigation within an hour of finding out about it — but only “started contacting impacted individuals within 36 hours.”

The mistake sparked alarm among some of the insurers involved in the trials.

MassMutual said a “small number” of its policyholders had been affected and that it had “paused” its pilot.

“We are aware that Grail proactively reached out to all our participants to address this issue as quickly as possible,” it said.

Principal, another big US life assurer that has customers affected, said it was reviewing its relationship with Grail after the incident.

With Post wires