"I got caught by cancer. I do want everyone to know that it is a very common and treatable form of cancer," the 80-year-old Hagman says in a statement.
Hagman has health problems before. In 1995, he received a liver transplant after having developed cirrhosis after years of heavy drinking. He has since spoken out in support of the National Kidney Foundation and their organ transplant awareness campaign.
Hagman is set to appear in at least the first four episodes of the show which begins shooting Oct. 17.
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