DeCarlo posted frequently about his health on his Facebook page. In March, he announced he would be starting 10 weeks of radiation treatment on his chest and groin. "I'm starting to feel like a bagel. This is gonna take a lot longer then I thought," he wrote.
Earlier this month, DeCarlo also posted that he had fractured his shoulder, "to go along [with] all the other medical problems."
"I try to stay positive," he told the Connecticut Post last year, "but there is always the thought that you won't get cured."
In 1969 "Na Na Hey Hey Kiss Him Goodbye" topped the Billboard Hot 100 for two consecutive weeks and went on to become one of the nation's most enduring sports anthems. Despite writing and singing on the track, DeCarlo lived his life in relative obscurity. After he and two fellow studio musicians wrote, produced and recorded the song, Fontana Records assembled a band called Steam to perform it live and who were credited as the song's performers.
"That hurt me," DeCarlo told the Connecticut Post. "I remember driving to the railroad station hearing the song on the radio and just wanting to yell out the window 'That’s me!..I fell into a deep depression.'"
A 2011 documentary by Pittsburgh radio host TJ Lubinsky called My Music: '60s Pop, Rock & Soul on public television helped to acknowledge DeCarlo's due credit on the song.
Watch DeCarlo perform "Na Na Hey Hey Kiss Him Goodbye" in 2012 here: