Kara Laing apologized to breast cancer patients on Thursday as she finished testifying at the Cameron inquiry. (CBC)

A senior oncologist in St. John's has apologized for what breast cancer patients have endured because of scores of flawed tests.

Dr. Kara Laing, who played a key role in how Eastern Health responded to flawed hormone receptor tests after they came to light in 2005, concluded her testimony at the Cameron inquiry on Thursday with an apology to her patients.

"I certainly recognize that this has been very difficult for a number of patients and their families, and I want them to know that I certainly empathize with them for what has gone on, and I am sorry that this has happened," Laing said.

Laing used her final comments at the inquiry — which is examining how several hundred breast cancer patients received the wrong results on hormone receptor tests — to appeal for more equipment and additional nurses and pharmacists dedicated to cancer treatment.

Laing told the inquiry that there have been substantial improvements in how Eastern Health handles cancer cases, but said professionals there need additional resources.

"We've helped a lot of individual patients. I think we've improved the care of breast cancer patients and perhaps even improved the care of many other patients," she said.

"As we enter an era now where we are going to be doing more and more targeted therapy, then that becomes extremely important and extremely critical as we move on."

Meanwhile, Laing was questioned Thursday on two media briefings that Eastern Health gave in December 2006. The inquiry has been told that Eastern Health decided to withhold some information as it explained to journalists the results of a massive retesting program.

The Cameron inquiry was called after that information was later released.

But Laing, who spoke for Eastern Health during the briefings, testified that she cannot recall being part of any discussions that led to information being held back.

Laing said the important number presented at the time was the fact that 117 patients needed a treatment change. Laing and others would not answer questions about the overall rate of error.

"Again, I come back to being a clinician, the number I felt was important was number of people needing treatment change as a result of this," Laing told inquiry co-counsel Sandra Chaytor.

Although the inquiry has heard evidence about the decision-making process leading up to the December 2006 briefings, Laing said she cannot remember any such discussions.

An affidavit later registered with a then-pending class action lawsuit showed that the original results of more than 40 per cent of retested samples had been wrong.

Laing said, however, that determining such a rate is not easy. She said Eastern Health officials had not calculated the numbers themselves because so many factors needed to be taken into account.