Missouri Democrat Sen. Claire McCaskill announced on her social media accounts that she has breast cancer on Monday, a disease she says was detected through a routine mammogram.
"I very recently learned that I have breast cancer. It was detected through a regular mammogram," she wrote on her Tumblr account. "It's a little scary, but my prognosis is good and I expect a full recovery."
McCaskill, 62, said that she would spend the next three weeks in St. Louis receiving treatment.
She directed readers to her website for a record on how she would have voted on issues that may come before the Senate during her absence and plans on submitting questions for hearings she may miss.