ST. JOHN'S, N.L. - Newfoundland and Labrador's health minister says he's angry that he was led to believe by health board officials that all patients affected by the province's botched breast-cancer testing scandal were notified.

Ross Wiseman told a public inquiry Tuesday that the Eastern Health authority did not have the information necessary last year to make that claim.

But Eastern Health - and Wiseman - repeatedly made that assertion in advertisements, interviews with the media and letters to the editor after the full scope of the errors was revealed in May 2007.

"The insight I now have and the manner the information was gathered ... there was no way they could tell me that," Wiseman said.

Wiseman said the fact that Eastern Health persuaded him to make that claim has left him with emotions ranging "from anger to disbelief to shock."

"It's a source of great frustration," he said.

But Wiseman said he couldn't say whether he thought Eastern Health was deliberately misleading the public in not providing full disclosure.

The inquiry is looking into how nearly 400 patients received the wrong results on their breast-cancer tests over an eight-year span.

It is also trying to determine whether Eastern Health and any other responsible authorities notified patients and the public in an appropriate and timely manner once the mistakes were discovered three years ago.

The inquiry is focusing on hormone-receptor tests, which are used by doctors to determine the course of treatment for breast-cancer patients.

If patients are found to be estrogen-and/or progesterone-positive, they may respond to hormone therapy such as Tamoxifen. If not, they may be given a range of other treatments, or no treatment at all, depending on the characteristics of the patient's cancer.

Problems with the testing weren't detected until the spring of 2005, when doctors began questioning the hormone-receptor test results of a patient with invasive lobular carcinoma, a form of breast cancer.

After retesting, it was discovered that the initial test result was wrong, as were those for a small sample of other patients.

Eastern Health subsequently halted testing in its lab and transferred its hormone-receptor tests to Mount Sinai Hospital.

The health board then started a review of all hormone-receptor tests from 1997 to 2005.