McCaskill diagnosed with breast cancer
© Greg Nash

Sen. Claire McCaskillClaire Conner McCaskillThe Hill's Morning Report: Dems have a majority in the Senate (this week) Schumer to meet with Kavanaugh on Tuesday GOP leader criticizes Republican senators for not showing up to work MORE (D-Mo.) has been diagnosed with breast cancer.

The senator made the announcement Monday in a post titled "I very recently learned that I have breast cancer," which she tweeted.

She said that she expects to make a full recovery and will be in St. Louis for the next three weeks undergoing treatment.

"It’s a little scary, but my prognosis is good and I expect a full recovery," she wrote.

McCaskill said her staff will continue to work to "assist Missourians," and she will be posting information on her Senate website and in the congressional record on how she'll vote on upcoming issues.

She will also submit questions in writing for missed Senate hearings.

"Thank you for the honor of serving you in the Senate," she wrote.

Rep. Debbie Wasserman Schultz (D-Fla.), a breast cancer survivor, released a statement Monday wishing McCaskill a quick recovery.

“Senator McCaskill is a consummate public servant and tenacious fighter who will battle her cancer with the spirit and determination that we have all come to admire and respect," said Wasserman Schultz, who leads the Democratic National Committee. 

“I wish her a speedy recovery and look forward to her return to the Senate where I'm confident she will continue to 'fight like a girl', as she joins our community of sister survivors.”