The 81-year-old chief executive officer of Berkshire Hathaway said in a letter his doctors have told him his condition "is not remotely life-threatening or even debilitating in any meaningful way," NBC News reported.
"I will let shareholders know immediately should my health situation change," Buffett said, adding a dead-pan acknowledgment of his mortality. "Eventually, of course, it will; but I believe that day is a long way off."
The investment guru said he will start a two-month treatment of daily radiation in mid-July.
Buffett said in February he has chosen his successor at Berkshire Hathaway, but has not divulged who it is.