Democratic Sen. Claire McCaskill announced Monday that she has breast cancer.

The 62-year-old Senator from Missouri said that she would take a three week absence from her office to receive treatment in St. Louis.

“I very recently learned that I have breast cancer. It was detected through a regular mammogram. It’s a little scary, but my prognosis is good and I expect a full recovery,” McCaskill said in a heartfelt post on the blogging platform Tumblr.

McCaskill, a Democrat, said she would remain diligent during her missed time that she would be posting how she would have voted to her Senate website, as well as submitting questions in writing for any missed hearings.

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