Too many of New Zealand’s breast cancer sufferers are having 'unnecessary' mastectomies, according to the Breast Cancer Foundation.

New research from the Foundation claims breast conserving surgery and radiation can lead to a higher overall survival rate.

Breast Cancer Foundation research manager Adele Gautier says guidelines suggest 70 percent of surgeries should be breast conserving surgery.

"Right now, in New Zealand, that's more like 55 percent. About a third of the people who could be having breast conserving surgery are having a mastectomy instead."

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