Actor Gary Sinise shares tribute to son, Mac, after 33-year-old died ...

Actor Gary Sinise shared a heartbreaking tribute to his son, McCanna Anthony “Mac” Sinise, after his passing earlier this year following a rare spine cancer diagnosis.

The “Forest Gump” actor announced Tuesday on the Gary Sinise Foundation website that Mac Sinise died on Jan. 5, five years after he was diagnosed with chordoma. He was 33 years old.

“Like any family experiencing such a loss, we are heartbroken and have been managing as best we can,” Sinise wrote in the letter. “As parents, it is so difficult losing a child.”

“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. He fought an uphill battle against a cancer that has no cure, but he never quit trying,” Sinise added.

Mac Sinise was first diagnosed with chordoma in August 2018. He underwent multiple spine surgeries to remove the initial tumor, but the chordoma returned and began to spread.

According to the National Cancer Institute, one in a million people worldwide are diagnosed with chordoma each year. Chordomas are difficult to treat because they grow “near important tissues like nerves and blood vessels.”

The cancer left Sinise paralyzed from the chest down, but he used his limited mobility in his right arm to pursue his passion project — in his final year, Sinise dedicated his time to creating music with an old friend and his father’s bandmates.

Sinise recorded two pieces, one unfinished from his college days and another on the harmonica, which he learned to play while undergoing medical treatment. His success inspired Sinise to create an entire album.

The album titled, “Resurrection & Revival,” will be available soon.

“He gave his family and friends so much during his 33 years, and he accomplished great things in those final months,” Gary Sinise wrote. “Thank you, Mac. You did it. Resurrection & Revival will live on. And so will you. In our hearts forever.”