Expensive extra scans using MRI on breast cancer patients make no difference to the number of patients who have a repeat operation, scientists said on Friday, raising questions about whether the scans are worth it.

A study of 1,623 women with breast cancer found that those who have a conventional triple assessment of their cancer are no more likely to be told they need a repeat operation than those assessed using magnetic resonance imaging (MRI) as well.

“Our results have important implications in routine clinical practice for the appropriate use of health-service resources and patient burden on health services,” said Lindsay Turnbull of Britain’s Hull University and Hull Royal Infirmary, who led the study. “MRI is an expensive procedure.”

Turnbull said that since the use of MRI scans in breast cancer patients is similar in many countries worldwide, her findings should be taken into account by all health authorities.

“We believe that our findings are generalisable to all healthcare providers, and show that MRI might not be necessary in this population of patients in terms of reduction of reoperation rates,” she wrote in the Lancet medical journal.

Siemens, General Electric and Philips Electronics are among the major makers scanning technology like magnetic resonance imaging, computed tomography (CT) and positron emission tomography (PET).

The industry has drawn some criticism in the United States where use of expensive scans has risen sharply in recent years.

Critics say many scans are unnecessary and often don’t improve results.

Turnbull’s study took place in 45 centers across Britain where the 1,623 women were all given a standard triple assessment - a clinical examination, an x-ray or ultrasound image of the breast, and lab tests to assess the tumor’s pathology - and then received either MRI or no further scans.

The researchers found 19 percent in the MRI group needed reoperation versus 19 percent of those who had no MRI.

Yet while the outcomes for patients were virtually the same, the costs - both in terms of hospital resources and patient time - were higher for those who had MRI scans, they said.

Breast cancer is the most common cancer in women worldwide, accounted for around 16 percent of all female cancers.

It kills around 519,000 people globally each year, but the World Health Organization says survival rates vary widely from more than 80 percent in the United States, Sweden and Japan to under 40 percent in low-income countries.

The researchers said their findings should benefit Britain taxpayer-funded National Health Service (NHS) since they show MRI might be unnecessary in some scenarios and “could assist in improved use of NHS services.”

SOURCE: The Lancet, February 13, 2010.