Brad Arnold, the lead singer of 3 Doors Down, announced that the American rock band's summer tour would be canceled for a heartbreaking reason — he has been diagnosed with Stage 4 kidney cancer that has spread to his lungs.

Doors Down lead singer Brad Arnold opened up about his health struggles in a recent video to fans, revealing he's been diagnosed with kidney cancer.

Brad Arnold, the lead singer of the rock band 3 Doors Down, says he has been diagnosed with a form of kidney cancer.