Dr Brett Says: The accuracy rates and side effects of many of the tests we rely on in modern medicine can be really concerning. Especially when we are talking about such drastic procedures. I always find it strange when this testing is counted in the statistics as prevention when it is really only early detection and it isn't even all that good at that. The best form of prevention of course is eating, thinking and moving in a healthy way!

 From abc.net.au 

 TONY EASTLEY: Australian researchers have found that as many as a third of women diagnosed with breast cancer may not need treatment.

The researchers from the University of Sydney say they found that the screening process is far from perfect and women often go on to have surgery and chemotherapy that is unnecessary because the cancers detected are not life threatening.

Cancer experts are warning that breast screening is valuable and continues to save lives.

Simon Santow reports.

SIMON SANTOW: More than half of all Australian women aged between 50 and 69 currently get screened for breast cancer.

Screening occurs in women who don't have symptoms for the disease.

Just as more women are getting screened, a Sydney University study has found that over-diagnosis too is a growing side effect of the process.

ALEX BARRETT: I think what it means is for people thinking about extending the screening program, that this is another piece of evidence that over-diagnosis of cancer is a real possibility and it is a real and important downside of cancer screening.

It is something we need to keep in mind when we are thinking about implementing cancer screening and it is something that we need to do a better job of giving women information about so that when they come to be screened, we actually give them fair and balanced information.

SIMON SANTOW: Study co-author, epidemiologist Professor Alex Barratt.

ALEX BARRETT: This is one of the downsides and it is another piece of evidence that the downsides are, this particular one, is more significant than we have realised until now really.

SIMON SANTOW: Dr Barratt says her study for the first time takes into account increases in risk factors for cancer which have coincided with the advent of a screening programme.

ALEX BARRETT: And the most important ones are hormone replacement therapy and increasing rates of obesity, overweight and obesity and those risk factors have affected women of the same age. So it was possible that the increase that we were seeing was due to those factors, not to the screening.

Even allowing for those two things we still found this excess and the only way that we believe that it is explainable is that screening is actually causing this by diagnosing cancer so they are very slow growing and that we would not have found in the absence of screening.

SIMON SANTOW: Professor Ian Olver is the chief executive of Cancer Council Australia. He says he's wary of the study and it needs to be seen in a broader context.

IAN OLVER: The good news about breast screening is that it reduces the mortality of the target group by 35 per cent.

SIMON SANTOW: Professor Olver says the screening isn't faultless and more research is needed to help eliminate false positive results.

IAN OLVER: What these new studies show is that it is not a perfect test and we need to take that into account but they are based on population studies and they don't given any indication as to what an individual woman should do.

SIMON SANTOW: Do you agree that these studies are pointing out that some women are receiving treatment when they don't actually need it?

IAN OLVER: Oh, that is what the studies undoubtedly show - that the test is not accurate enough to tell us which women have indolent breast cancers and which have aggressive breast cancers that need immediate treatment. And we need to really direct research to try and discriminate between those two.

TONY EASTLEY: Professor Ian Olver, chief executive of Cancer Council Australia, ending Simon Santow's report.