WASHINGTON (Reuters) – Senator Claire McCaskill will be absent from Congress for the next three weeks as she undergoes treatment for breast cancer, the Missouri Democrat wrote in a blog post on Monday.

McCaskill, who leads the Senate Special Committee on Aging, said she will post online how she would have voted on any matters that come up during her absence and will submit questions in writing for any missed hearings.

“It’s a little scary, but my prognosis is good and I expect a full recovery,” McCaskill wrote.

(Reporting by Megan Cassella; Editing by Eric Walsh)

Photo: Senator Claire McCaskill (D-MO) of the Senate Commerce, Science and Transportation Subcommittee questions a witness in Washington July 17, 2014. REUTERS/Gary Cameron