The news, which was first reported by the New York Post, came as other NBA owners took initial steps to forcing Sterling to sell the Clippers, which lost 100-99 Thursday in its playoff match-up against the Golden State Warriors.
The teams will play Saturday in a deciding Game 7.
VIDEO: Donald Sterling Has Cancer
The Post, citing sources, reported that Sterling, 80, has been battling prostate cancer for an extended period of time.
Sterling was banned for life from the NBA and fined $2.5 million by commissioner Adam Silver earlier in the week after racist remarks he made were published online.
After Thursday’s loss, Clippers players and coaches said they were unaware of Sterling’s cancer.
"If that is true, my thoughts and prayers are with him," power forward Blake Griffin said. "Nobody deserves to go through something like that."
Point guard Chris Paul, who also said he hadn't heard about the cancer, called it "truly unfortunate," while coach Doc Rivers said he didn't know about it and that he hoped it wasn't true.
The league's 10-member advisory-finance committee held its first meeting about Sterling Thursday. The committee said in a statement that it "unanimously agreed to move forward as expeditiously as possible" on the process of terminating Sterling's ownership and planned to reconvene next week.
One of the mysteries of the situation involves the origins of the recordings featuring Sterling's rants to his former companion V. Stiviano. The attorney for Stiviano told the Los Angeles Times Thursday that she gave copies of the recordings to a handful of friends for "safekeeping," with one of those friends purportedly leaking the audio.
Stiviano did not release the tapes, he said.
"One of those friends apparently wanted to make money and sold it to TMZ," lawyer Mac Nehoray said.
With Sterling facing a forced sale of his team, prospective celebrity owners have emerged, including Oprah Winfrey, Matt Damon and Magic Johnson. Johnson, whose picture with Stiviano triggered Sterling’s now-infamous rant, remains coy on whether he wants to buy the team.
"I have been saying 'no' all the time," Johnson said. "I think we will see what happens. I will be owning an NBA team sometime."
The Associated Press contributed to this report.