NSW govt defends handling of chemo bungle

The NSW government has defended its handling of a chemotherapy scandal at Sydney's St Vincent's Hospital following revelations the hospital was slow to respond to concerns one of its doctors was under-dosing cancer patients.

Of the 78 patients treated with low doses of a chemotherapy drug by oncologist Dr John Grygiel, 23 have died - three of non-cancer causes and four of an unspecified cause.

A government-ordered review was unable to attribute their deaths to the incorrect dosing.

But it found St Vincent's was made aware of the practices as early as 2005 and misled the public about the bungle after the revelations were aired in a media report.

Acting Premier Troy Grant said he was horrified by the report's findings but had confidence two independent investigations would address the issues arising from the case.

"No-one in government is shying away from how bad this situation is," he said on Wednesday.

"I'd rather the experts complete their investigation so we know the whole story.

"The family and victims deserve the entirety of this story to be known and investigated by those best placed to do that."

He said he was confident St Vincent's Hospital CEO Toby Hall would take the necessary steps to resolve the issue.

"He's been completely apologetic for what has occurred and I think the contrition is real and genuine," he said.

NSW Labor and the Greens have called for a special commission of inquiry into the scandal, saying it's the only way to restore trust in the health system.

St Vincent's apologised to patients, their families and the public on Tuesday, saying it had not lived up to the "the high standards we set ourselves".

"We failed to appreciate the seriousness of the situation: early questions about the doctor's dosage practice should have led to a formal examination," it said in a statement.

Dr Grygiel was stood down in February and is currently overseas.

His lawyer, Stephen Blanks, told AAP his client was pleased the inquiry had found St Vincent's Hospital had made incorrect statements about what disciplinary action it had taken.

He said Dr Grygiel was looking forward to giving his evidence to the inquiry when he returns.