NEW YORK — Lou Koller, the longtime frontman and co-founder of the iconic New York hardcore band Sick of It All, has died after a two-year battle with esophageal cancer pagesix.com . He was 59.

The watershed moment in the punk rock community was announced on Friday, July 25, 2026, in a heartfelt statement shared by the group on Instagram pagesix.com .

Koller first revealed his diagnosis in June 2024, when doctors discovered a cancerous tumor in his esophagus that had spread to his stomach, forcing the band to cancel its European tour while he underwent aggressive treatment pagesix.com . After months of chemotherapy, the rocker shared in May 2025 that he was cancer-free, but tragically, the disease returned shortly after pagesix.com .

Tributes quickly poured in from across the music and entertainment world, highlighting Koller's far-reaching influence. WWE star CM Punk wrote, “Love you Lou and SOIA. Thank you for the soundtrack for my life. Sending hugs” pagesix.com . Singer-songwriter Chuck Ragan added, “Lou was indeed a pillar in our world of music to me and will never be forgotten,” while Pennywise guitarist Fletcher Dragge called him “a true gentleman and a pioneer” pagesix.com .

Pennywise’s lead singer Jim Lindberg also shared his grief, writing, “The best to do it, and a real good human. Devastated for your loss, for the family, for all of us” pagesix.com .

As the music community mourns, Koller’s legacy as a seminal voice in hardcore punk remains firmly intact. His energetic stage presence, authentic connection with fans, and unwavering dedication to the DIY ethos will continue to inspire generations of musicians and fans alike.