Hundreds mistakenly told they might have cancer, test company Grail says

CHICAGO -- Hundreds of people using the test company Grail were wrongly told they might have cancer, the company said in a statement Monday.

Grail said a software glitch related to their telemedicine vendor, PWNHealth, caused them to send letters to about 400 patients saying they might have cancer when they do not. Grail said the glitch affected customers who had ordered their "Galleri" test.

Grail said it was notified by PWNHealth about the issue on May 19. They said the wrong letters were sent from May 10 to May 18. The company said the incorrect letter was not triggered by an incorrect lab test result but instead from a now-disabled PWNHealth software configuration.

"Due to PWNHealth's software configuration issue, individuals who had recently ordered Galleri received a form letter in the mail from PWNHealth stating incorrectly that a cancer signal was detected," a spokesperson told ABC News.

Grail also said no patient heath information was disclosed or breached due to the issue, and no patient harm has been reported.

"After being notified of the incident, GRAIL immediately began outreach by phone or email to all individuals who received the PWNHealth letter, and we continued our efforts until we confirmed we successfully reached each individual via phone, email, or letter," the company said in a statement.