Approximately 400 individuals got an inadvertent cancer scare.
The people had ordered the Galleri test, which says it can detect signals indicating the presence of over 50 types of cancer.
Grail, the biotech company that developed the test, said its telemedicine vendor, PWNHealth, issued letters with inaccurate information. The letters reportedly went out between May 10 and May 18.
Grail said the inaccurate letters were produced due to a PWNHealth software configuration issue.
Upon learning about the issue, Grail said it reached out to all customers who received one of the letters.
"We continued our efforts until we confirmed we successfully reached each individual via phone, email, or letter," the company said in a statement to Scripps News.
Grail insists that the mistake was in no way related to inaccurate tests, noting that some of the patients who received the letter had not even had their blood drawn yet.
The company touts the accuracy of its test, saying only 1 out of every 200 people tested could expect to receive a false positive result.
Grail recommends that the test be used with other, more traditional screening methods, to get the most accurate diagnosis and potential treatment plan.
The test is only available with a prescription from a doctor.
