Mac Sines, the son of American actor Gary Sines, star of the film "Forrest Gump," died at the age of 33 after a long battle with a rare type of cancer, his family announced.

He died on January 5 and was buried on January 23, according to a tribute published by the Gary Sines Foundation, which supports wounded veterans in the military.

Sines wrote: "Like any family suffering such a loss, we are deeply saddened and coping as best as we can."

"As parents, it is very difficult to lose a child. My heart goes out to everyone who has suffered a similar loss, and to anyone who has lost a family member."

The actor added, "He had been playing drums since he was nine years old and often played alongside his father as part of the LT Dan band."

In 2018, he was diagnosed with chordoma, a rare type of bone cancer that develops at the base of the skull, or in one of the vertebrae, or at the end of the spinal column.

Chordoma affects about 300 people annually in the United States, according to the National Cancer Institute.

His father said Mac underwent surgery. However, the cancer returned and eventually spread.

Sines wrote: "This began a long battle that increasingly disabled him over time," leaving Mac eventually unable to play the drums.

Despite his deteriorating health, Mac learned to play the harmonica and worked with friends on a music album titled "Resurrection & Revival," which was released for printing the week he died.

Sines wrote: "While our hearts ache from missing him, we feel comfort knowing that Mac is no longer suffering, and he inspired and moved us by the way he handled it."

"He fought a tough battle against an untreatable cancer, but he never stopped trying."

Sines added, signing the tribute as "Proud father of Mac Sines": "We blessed your presence in our lives as a son, brother, and friend, and we will miss and love you forever."

In addition to his most famous role as Lieutenant Dan in the film "Forrest Gump," Gary Sines appeared in the films "Apollo 13," "The Green Mile," and "Of Mice and Men," as well as the television series "CSI: New York."