WASHINGTON (AP) -- Researchers are linking estrogen therapy to benign breast lumps in women.

It's the latest risk connected to hormone therapy after menopause.

Another type of hormone therapy -- estrogen plus progestin -- is already known to raise the risk of breast cancer. Now researchers are finding that women using estrogen alone may double their chances of getting non-cancerous breast lumps.

That raises concerns beyond the extra biopsies and worries such lumps can lead to. That's because one type of benign growth is suspected of being a first step toward developing cancer 10 years or so later.

The study is published in the Journal of the National Cancer Institute.

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