The 58-year-old star has told the magazine she discovered a small tumour "no bigger than a pea" in her Sydney home just seven days ago.
Kennerley found the lump on her breast while sewing extra bling on a beaded bra for a routine on Dancing With The Stars.
"If it hadn't been for that, I might never have noticed the lump," she told New Idea.
"It's a funny thing - the doctor told me if I hadn't lost 8kg on DWTS, and if I hadn't been fiddle-faddling with that beaded bra, I might not have realised there was anything wrong for months. I guess you could say DWTS may have saved my life".
While Kennerley says doctors have told her radiotherapy is "a given" and at least part of her breast must be removed.
Kennerly says she didn’t have any of the risk factors and went public with her story to urge all women to undergo regular mammograms.
"That’s why I thought it could never happen to me. I’ve always looked after myself, but here I am," she said.
Full story in today's New Idea