A Third of Breast Cancer Patients 'Treated Needlessly'
One-third of women diagnosed with breast cancer in public screening programs are treated needlessly because their tumor will not be life-threatening, the British Medical Journal reported.
Scandinavian researchers highlighted the dilemma facing doctors when it comes to detecting and treating breast cancer. Not all breast cancers kill, though.
In some cases, the cancer will grow so slowly that the patient will die of other causes before it produces symptoms, or it might remain dormant or even shrink over the years.
Because doctors have no idea whether a cancer will be lethal or harmless, they tend to treat all patients diagnosed with a tumor. But cancer treatment, using powerful drugs, radiotherapy, or surgery, causes harm.
So it is vital to know how many patients may be being treated unnecessarily, especially given the huge investment in having women undergo regular mammograms.
Karsten Jorgensen and Peter Gotzsche of the Nordic Cochrane Centre in Copenhagen pored over data from screening programs in Australia, Britain, Canada, Norway, and Sweden.
They looked at trends seven years before and seven years after the programs were implemented.
They found that, when screening programs were introduced, doctors did indeed spot more cases of breast cancer - but also treated more women who would not have needed it.
"One in three breast cancers detected in a population offered organized screening is over-diagnosed," they said.
In an accompanying editorial in the British Medical Journal, Gilbert Welch, a professor at the Dartmouth Institute for Health Policy and Clinical Research in Vermont, said the findings raise key questions about the trade-off between deaths the screening programs avoid and the harm treatment programs inflict.
One study has suggested that one death is avoided for every two women who are over-diagnosed, while another puts the ratio far higher, at one death avoided for every 10 cases of unnecessary treatment.
"Mammography undoubtedly helps some women but hurts others," Welch said. "No right answer exists. Instead, it is a personal choice."
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