The Quebec government will likely have to redo an untold number of breast cancer tests in the wake of a study that suggested some women may have received the wrong treatment for the disease due to faulty test results.

Quebec Health Minister Yves Bolduc said Tuesday he has established a committee of health experts to review test results and report back to him by the end of this week with the number they feel need to be redone.

With 6,000 women diagnosed with breast cancer in Quebec each year, do-overs could number in the thousands.

Breast cancer patients in the province became concerned last Wednesday when research from the University of Montreal found that 15 to 20 per cent of tests used to identify markers for hormone therapy were flawed.

The research also found errors for up to 30 per cent of tests that identify protein markers.

On Sunday, researcher Louis Gaboury said his study's results do not prove that 20 to 30 per cent of women received the wrong treatment.

He said his study found variability in results between laboratories, a problem that would be alleviated by implementing province-wide outside quality controls for Quebec's pathology labs.

But he did acknowledge that some women may have been incorrectly treated and that some tests would need to be redone.

Bolduc said Tuesday he will speed up the process to establish a provincial strategy for laboratory quality controls.

Bolduc also said that any of the province's 45 labs that do not currently have external quality controls will have to submit their results to a lab that does.

CTV Montreal's John Grant reported Tuesday that it is unclear how many labs do not have external quality controls. However, patients who have had tests done at university hospitals can rest assured because those facilities do have such controls.

Bolduc said it is important to ensure that there is little or no variability among test results between labs.

"It's just a measure of quality control and now we want to be sure that every lab has this control," Bolduc said.

On Sunday, Dr. Gaetan Barrette, president of the Quebec Association of Medical Specialists, blamed the study's results on an underfunded system that is plagued by outdated equipment and staff shortages.

"Are we lacking pathologists? A lot. Do they have the proper equipment? It's a blatant no," Barrette said.

The head of the Quebec College of Physicians said Sunday the shortage of pathologists and equipment would also hinder retesting efforts.

"If we had to start re-examining all the tests of all the patients over the last five years, we already have a shortage of pathologists, where would we get them [to re-do the testing]?" said Dr. Yves Lamontagne. "There isn't a province, there isn't a country that has the means to say we will start all over."

The scare echoes events in Newfoundland and Labrador, where an inquiry earlier this year found that problems throughout the health-care system led to nearly 400 breast cancer patients receiving incorrect test results.

At least 108 of those patients have died, but it is not known how many did so because they did not receive potentially life-saving treatment.

With files from The Canadian Press