New research concerns of overdiagnosis risk in screening earlier

Dr Alia Kaderbhai, Chair of the RACGP Specific Interests Breast Medicine network and BreastScreen Victoria GP Advisor, told newsGP that when weighing up the risk versus benefit for starting screening at age 40, the rationale is unjustified.

Dr Kaderbhai’s comments are in response to new research from the University of Texas MD Anderson Cancer Center and Fred Hutch Cancer Center that suggests developing a breast screening strategy that targets women from age 40, based on a baseline breast density measure, could be the most effective way to reduce breast cancer mortality.

‘Starting screening from age 40 onwards is unlikely to significantly reduce the number of late stage tumours [those bigger than 2 cm],’ she said.

‘[That] means that breast screening in this way is unlikely to reduce breast cancer mortality or lead to less invasive treatment.’

‘We know that with increased screening we can “over-diagnose” patients – [this] refers to detection of cancers that might never have progressed or become symptomatic in a patient’s lifetime,’ she said.

‘Already about one in three breast cancers detected in women offered screening are likely over-diagnosed.

‘There is also a risk of about 10% for false positive results. This leads to unnecessary investigations that are sometimes invasive, as well as increased anxiety for men and women.’

Dr Alia Kaderbhai.

newsGP says Dr Kaderbhai’s concerns are in line with those expressed by experts from the University of California, who penned an editorial to accompany the research. They argue that while breast density is an important risk factor to include in risk-based screening strategies, that it should be combined with age and other risk factors that optimise benefits and minimise harms.

The editorial by University of California says that until a more robust risk-based strategy is identified, data supports screening from age 50–74, every two years, newsGP reports.

Read the full story on newsGP here.