TORONTO - The governing Liberals should apologize to two women whose breasts were removed after they were mistakenly diagnosed with cancer and explain why they didn't move sooner to warn the public that other errors may have been made, critics demanded Wednesday.

Laurie Johnston is suing her surgeon, pathologist and two hospitals in the Windsor, Ont., area over the mistaken surgery, which she claims has impeded her ability to work.

Janice Laporte, who also had her breast mistakenly removed by the same surgeon -- Dr. Barbara Heartwell -- in 2001, also sued and her case was concluded in 2002.

Given that people can now apologize in Ontario without admitting liability, the Liberals should take advantage of their own law and tell the women they're sorry, said Conservative health critic Christine Elliott.

It's the right thing to do, added NDP health critic France Gelinas.

"Think about it: you trusted the system enough that they convince you that you were sick when you were not, and they convince you to have drastic surgery that you didn't need," Gelinas said.

"Something went drastically wrong. The least you can do is apologize."

The government also needs to explain why it didn't come out and warn patients in the Windsor area when it discovered that other mistakes may have been made, they said.

"There's a lot of question marks there, and its not fair to leave people hanging like that," said Elliott.

An internal document drafted by the Erie St. Clair local health integration unit (LHIN), which oversees the Windsor-area hospitals, claimed six patients were misdiagnosed by the same pathologist involved in Johnston's case.

The document, which would have been distributed to senior managers at the LHIN, also claimed that two of the patients underwent unnecessary surgeries and attributed the error, in part, because Dr. Olive Williams had cataracts.

The LHIN said it sent the information to the ministry Feb. 11 -- before Johnston went public with her story and Laporte came forward, which sparked several investigations.

But Health Minister Deb Matthews said she only learned about the mistakes in mid-February, when Johnston went public with her story, and called a provincial probe in March.

The findings of that investigation into pathology results in the Windsor area are expected to be delivered to Matthews this week.

"We acted quickly to actually understand the whole issue," she said. "I look forward to the release of that report very soon."

Doctors are also required to report a mistake to the hospital administration -- not just the patient -- under a new law that was "informed" by the Windsor cases, Matthews said.

"It didn't make sense to me either that the hospital was not informed," she said.

That's not good enough, said NDP health critic France Gelinas.

In Johnston's case, the hospital brought the potential mistakes to the attention of the LHIN, who in turn informed the ministry.

"And all of the players chose to do nothing," she added.

Windsor's Hotel-Dieu Grace Hospital, where Johnston underwent the mastectomy, has said it first learned of the mistake through the media and has apologized for the error.

Williams, who is named in Johnston's lawsuit, has denied in court documents that she was negligent or misdiagnosed Johnston.

However, her law firm declined to comment on the claims that five other patients were misdiagnosed and that Williams had poor eyesight.

The College of Physicians and Surgeons of Ontario is also investigating Heartwell and Williams.