Gary Sinise is honoring his late son McCanna Anthony "Mac" Sinise, who died Jan. 5 from a rare form of cancer called chordoma. He was 33.
The actor, famous for his roles in "Forrest Gump," "Apollo 13," "The Green Mile" and "CSI NY," posted a photo of his son on Instagram Tuesday, with text over the photo that read, "In Honor & Memory of McCanna 'Mac' Sinise 1990-2024."
In the caption, the "Of Mice and Men" star directed his followers to the Gary Sinise Foundation website to read his heartfelt tribute to Mac.
"Like any family experiencing such a loss, we are heartbroken and have been managing as best we can," he wrote in the tribute. "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. We've all experienced it in some way. Over the years I have met so many families of our fallen heroes. It's heartbreaking, and it's just damn hard."
He noted that his son's battle with cancer lasted five and a half years, adding that "it became more and more challenging as time went on."
The actor said his son was diagnosed in 2018, the same year his wife Moira Harris was diagnosed with stage 3 breast cancer, but she is now cancer-free after months of treatment.
MORE: Shannen Doherty shares an update on her cancer treatment"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 continued. "He fought an uphill battle against a cancer that has no cure, but he never quit trying."
"I am so blessed, fortunate, and proud to be his dad," he added.
Chordoma is a slow-growing cancer of tissue found inside the spine, according to the National Cancer Institute, which states that 1 in 1 million people worldwide are diagnosed with the disease each year.
Also known as notochordal sarcoma, it is most often found near the tailbone (called a sacral tumor) or where the spine meets the skull (called a clival tumor). The average survival is around 10 years after diagnosis depending on where the tumor is and how much can be removed by surgery, according to the NCI.
In his tribute this week, Gary Sinise also spoke about Mac Sinise's zest for life, his contribution to his foundation -- which works to create and support programs that help "defenders, veterans, first responders, their families, and those in need," according to its website -- and his son's passion for music (he completed a full album titled "Mac Sinise: Resurrection and Revival," prior to his death).
Gary Sinise said he also hopes that by sharing his family's story, it will "shine a little bit of light on what has been a difficult time for us," adding that Mac Sinise "was truly a light for all of us."
"An incredible inspiration to those who knew and loved him, he faced his battle with grace, courage, and love," he continued. "Even with one setback after another, he never stopped living and learning, creating, and giving, and loving."
Gary Sinise concluded the message with a note to his son, writing, "We were blessed to have you in our lives as son, brother, and friend...and we will miss you and love you for eternity."
In addition to Mac, Gary Sinise is also a father to two other children, daughters Sophie and Ella.
