Claire McCaskill, who has represented Missouri in the United States Senate since 2007, announced Monday that she was recently diagnosed with breast cancer.
"It’s a little scary, but my prognosis is good and I expect a full recovery," McCaskill said in a post on her Tumblr page.
The Democrat said that she will take a three-week break from the Senate while she receives treatment, but thatshe will post on her senate web page how she would have voted on matters that come before the body while she is away.
The cancer was diagnosed during a routine mammogram, she said.
McCaskill describes herself on her Tumblr page as a moderate Democrat "who irritates folks of both parties with some regularity." She serves on the Armed Services Committee, among others.
She's a frequent social media user, who sometimes shares her personal life on Twitter, including a picture of brownies she baked for fellow jurors when she was serving jury duty last month.