Samples taken from about 2,100 Quebec breast cancer patients will be re-examined to make sure the women are receiving proper treatment, the provincial Health Ministry announced Thursday after a committee of experts recommended it as a precautionary measure.

No women will face new examinations, according to Dr. André Robidoux, chair of the committee.

"We did not think that tests had to be re-examined necessarily," Robidoux said.

But media coverage of a study that showed variations in test results generated anxiety among breast cancer patients, Robidoux said.

Rechecking those results should calm those fears, he said.

In the national assembly Thursday, opposition parties said the study showed evidence the testing was inaccurate. Parti Québécois health critic Bernard Drainville said Health Minister Yves Bolduc has tried to suppress the facts.

Bolduc accused the PQ of trying to make political gain on the issue. He said the findings of the committee of experts are conclusive.

The retests will be done on samples already taken from women between April 1, 2008, and June 1, 2009, and who had a tumour of one centimetre or more.

The testing will be completed before Dec. 31.

Robidoux said about 100 women may have to change their treatment based on the discrepancy percentage in this type of analysis.

Quebec has been working for a year on provincewide quality control measures for its pathology labs, but the association that represents the province's medical specialists says the problems in the labs are long-term and systemic.