Christopher Ciccone, who devoted himself to his older sister Madonna — living with her, warning her of impending arrest and directing her world tours of the early 1990s — but who later, after feeling cast aside, wrote a memoir chronicling experiences that he described as “abuse,” died on Friday. He was 63.

The cause was cancer, his representative, Brad Taylor, said in a statement. He did not specify where Mr. Ciccone died.

After years when it seemed the siblings shifted between chilly distance and bitter feuding, Madonna published a statement on social media that praised Mr. Ciccone, fondly recalled the years of their closeness and described a reconciliation before his death.

“We soared the highest heights together and floundered in the lowest lows,” she wrote. “Somehow, we always found each other again.”

Mr. Ciccone (pronounced chick-OH-neigh) was with Madonna from just about the beginning: He choreographed the music video of “Everybody,” her debut single in 1982. He was there as a backup dancer during her early club dates. He endured her shouting as he went along for a ride to dizzying heights of celebrity.

“In many ways, Christopher was the most important and steadfast member of Madonna’s early inner circle,” Mary Gabriel, the author of “Madonna: A Rebel Life,” a biography of the singer, wrote in an email.