U.S. Senator Bob Casey revealed on Thursday that he as been diagnosed with prostate cancer.

Two Tweets sent by the Pennsylvania Democrat say that the diagnosis came as a shock last month, but Casey said he has an excellent prognosis.

“In the coming months I will undergo surgery, after which I am expected to make a full recovery,” Casey Tweeted.

Crediting medical care and family support, Casey said the recommended course of treatment will allow him to continue serving in Congress with minimal disruption.

Prior to coming to Washington, Casey served eight years as Pennsylvania Auditor General and two years as State Treasurer.