The Newfoundland health authority at the centre of a public inquiry maintains its testing labs are doing good work.

Patricia Pilgrim, a senior manager at Eastern Health, the province's largest health authority, reacted Thursday to testimony indicating quality problems at the authority's pathology labs.

Retired lab technologist, Les Simms, testified this week that up until he left his position in May 2008, there continued to be quality issues with cancer tissue specimens.

"They tried various things, but they're still getting sub-optimal tissue, whether it's from the fixation or not acquiring a proper technique for a proper piece of tissue or tissue too big or too thick," Simms testified Wednesday.

Fixation, the process of halting the deterioration of cells on a lab slide, has frequently been cited at the inquiry as a key problem at the St. John's lab.

On Thursday, Pilgrim told reporters that quality problems can be expected because of the nature of the complex testing.

"The technologist also did say that this is a very tricky type of specimen to get," Pilgrim said in response to the testimony. "And he really didn't know if you'd ever get it the way he thought it should be. But certainly as part of what we are doing now, we are getting every indication that the work we are doing is good work."

Pilgrim also noted that Eastern Health is taking part in external proficiency testing, and she said all indications are that the pathology labs are doing good work.

The public inquiry, headed by Justice Margaret Cameron in St. John's, is investigating why hundreds of breast cancer patients received faulty hormone receptor test results between 1997 and 2005. Hormone receptor testing is used to determine what type of treatment someone already diagnosed with breast cancer should receive.

The inquiry has been hearing testimony since March.