Casino magnate and GOP donor Sheldon Adelson has cancer and has not been at his company�s offices in Las Vegas since the end of December.

Adelson�s poor health was revealed earlier this week by one of his company�s attorneys during a court hearing in a years-old case brought by a Hong Kong businessman. The founder and CEO of Las Vegas Sands Corp. did not participate in the casino operator�s conference call with analysts and investors following its earnings report in January.

Attorney James Jimmerson told the court Monday that he learned last month �of the dire nature of Mr. Adelson�s condition, health.� The comment from the attorney came when discussing whether Adelson could sit for a deposition in the case and was first reported by The Nevada Independent.

Las Vegas Sands Corp. on Thursday told The Associated Press that Adelson has cancer.

�Mr. Adelson is still dealing with certain side effects from medication he is taking for the treatment of non-Hodgkin�s lymphoma,� company spokesman Ron Reese said in an emailed statement Thursday night. �These side effects have restricted his availability to travel or keep regular office hours.�

The effects haven�t prevented Adelson, 85, from fulfilling his duties as chairman and CEO, Reese said. The company expects he�ll return after he completes treatment.

Adelson also suffers from peripheral neuropathy, a condition that affects the nervous system.

The billionaire and his wife, Miriam, gave President Donald Trump�s campaign $30 million in 2016. They followed that by contributing $100 million to the Republican Party for the 2018 midterm elections.

Adelson is Las Vegas Sands� largest shareholder and regularly participates in the company�s earnings calls, but was absent when it reported results on Jan. 23. Sands President Robert Goldstein said at the time that Adelson was �a little bit under the weather.�

�We met with him yesterday,� Goldstein said of Adelson during the January call. �He�s taking some medications making him a bit drowsy, so he decided this morning to take a rain check on this one.�

Adelson was expected to testify in the case brought by Hong Kong businessman Richard Suen and his company, Round Square Co. He testified in 2013 and 2008 in the case�s two previous trials.

Suen has been seeking compensation because he said he helped Sands secure business in the Chinese gambling enclave of Macau. Sands has argued Suen didn�t help get crucial approval to build casinos in Macau and deserves nothing.

(AP)