Australian health authorities said Thursday there was no evidence French breast implants at the centre of a global health scare posed an extra rupture risk and their contents had been found to be safe.
The government-run Therapeutic Goods Administration (TGA) said there had only been 37 ruptures in 9,054 implants manufactured by now-defunct firm Poly Implant Prosthese (PIP) between 2002 and 2011, a rate of just 0.4 percent.
That compared with a generally accepted rupture risk of one in 10 implants within 10 years of insertion, meaning PIP implants were "well within the expected performance of breast implants", said TGA manager Rohan Hammett.
The implants were recalled from the Australian market in April 2010 over concerns from French medical device regulators about the risk of rupture.
Testing of the French-made implants' outer shell by Australian officials in July 2010 showed that they "complied with international standards and regulatory requirements for strength and rupture resistance," Hammett said.
"Importantly, laboratory testing of the silicone gel contained in the PIP implants done both in Australia and in the UK using cytotoxicity and genotoxicity studies has indicated the gel is non-toxic to the tissue around the implant even if the implant does rupture," he said.
There had been no cancer reports linked to ruptured PIP implants in Australia, he added.
The implants triggered a worldwide health scare after French authorities last month advised 30,000 women to have them removed due to increased risk of rupture.
Between 300,000 and 400,000 women in 65 countries are believed to have implants made with non-standard industrial-grade gel that the firm, once the world's third-largest silicone implant maker, used to cut its costs.
Authorities in many countries have advised women to consult their doctors, with nations such as Bolivia and Venezuela saying that in some cases the implants would be removed for free.
Australia's TGA said it was not clear whether any of the substandard implants had made their way onto the local market but there was "insufficient evidence" at this stage to warrant their routine removal.
"The best available expert clinical advice is that there is no current evidence in Australia to support removal of PIP implants in women in whom the implant has not ruptured," Hammett said.