Image by Getty Sheldon Adelson with his wife, Miriam Adelson, in February 2018.

Billionaire casino magnate and pro-Israel mega-donor Sheldon Adelson is being treated for cancer, Bloomberg reported.

Adelson, 85, has been out of his office since late December due to side-effects from his treatment for non-Hodgkin’s lymphoma. A lawyer representing one of Adelson’s casinos referred to his health as “dire” in court Monday.

A company spokesman told Bloomberg that Adelson’s illness has not kept him from acting as the chairman and CEO of the Las Vegas Sands Corp., Adelson’s casino empire. However, Adelson missed a call to investors in January.

Adelson is worth $39 billion, according to the Bloomberg Billionaire Index. He was the largest outside spender during the 2016 elections, and has donated hundreds of millions of dollars to Jewish and Israeli causes.

Ari Feldman is a staff writer at the Forward. Contact him at feldman@forward.com or follow him on Twitter @aefeldman