Kent Damon died on Dec. 14 after a long battle with cancer, the actor's rep confirms to ET. He was 74.
According to The Boston Globe, Kent died of multiple myeloma, a rare blood disease, after his condition had worsened in recent months. Damon -- who revealed that his father was battling myeloma while attending a benefit for Massachusetts General Hospital in 2011 -- had pulled out of several recent public appearances due to family matters.
Since news of his father's diagnosis, Damon has helped raise awareness and funds for cancer research and treatment. He's also attended several benefits for the Massachusetts General Hospital Cancer Center in Boston, as well as hostedd private fundraisers in Los Angeles.