Actor Gary Sinise’s son McCanna “Mac” Anthony Sinise died on January 5 at the age of 33 following a five and a half year battle with a rare cancer called Chordoma, his father announced.

Gary Sinise revealed the passing of his son in a statement posted to social media on Tuesday.

Sinise explained that his family was hit hard in the summer of 2018, with his wife, Moira, being diagnosed with stage 3 breast cancer in June of that year, and his son, Mac, being diagnosed on August 8, 2018 with “a very rare cancer called Chordoma.”

“Chordoma is a one in a million cancer. Originating in the spine, Chordoma affects, on average, only 300 people in the U.S. per year. In 70% of the cases the initial tumor can be removed, and it is cured. But in 30% of the cases, perhaps about 90 people per year, the cancer returns.”

While Moira went into remission and has been cancer-free ever since following months of treatment, Mac had a more challenging battle that lasted five and a half years, Sinise said.

Mac had underwent surgery to remove the initial tumor in September 2018, as well as another spine procedure in February 2019, to clear an apparent infection, but a follow-up scan in May 2019 had unfortunately shown that “Chordoma had come back and was spreading.”

“This began a long battle that disabled him more and more as time went on,” Sinise explained. “The cancer fight was getting harder, but throughout most of 2019 he was still able to come to the GSF office, until a third spine surgery in November of that year.”

Mac, who worked at Gary Sinise Foundation, his father’s charity and veterans service organization, ended up having to step away from his post at GSF in January 2020 in order to fight his battle.

“With Chordoma being such a rare form of cancer, there are very few medical centers doing research,” Sinise said. “During our long and challenging fight, we were blessed to have the support of the Chordoma Foundation.”

“They are the only organization whose sole mission, 24/7, is to find a cure for this rare orphan cancer and beat Chordoma,” the Of Mice and Men star added.

While fighting his battle, Mac, who was passionate about music and playing the drums since the age of 9, had been working on an album, titled, “Resurrection & Revival.”

“The week the album went to press, Mac lost his battle with cancer,” Sinise revealed.

“Like any family experiencing such a loss, we are heartbroken and have been managing as best we can. As parents, it is so difficult losing a child. My heart goes out to all who have suffered a similar loss, and to anyone who has lost a loved one,” the Forrest Gump actor said.

“While our hearts ache at missing him, we are comforted in knowing that Mac is no longer struggling, and inspired and moved by how he managed it,” Sinise added. “He fought an uphill battle against a cancer that has no cure, but he never quit trying.”

Sinise, who had not publicly disclosed his son’s cancer battle until December 29, 2023, went on to say, “I am so blessed, fortunate, and proud to be his dad.”

“Mac was a man who loved his Catholic faith, and there is no doubt that his strong faith sustained him through the awful 5 ½ year battle with this crippling Chordoma cancer,” he said.

“He gave his family and friends so much during his 33 years, and he accomplished great things in those final months,” the actor added. “With a glorious teaming of two old pals from college, his vision for this beautiful music was realized.”

Sinise also revealed that the album, “Mac Sinise: Resurrection and Revival,” will be finished and available soon, and can be pre-ordered here.

“Thank you, Mac. You did it. Resurrection & Revival will live on. And so will you. In our hearts forever,” Sinise said. “We were blessed to have you in our lives as son, brother, and friend… and we will miss you and love you for eternity.”

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