American Idol champ David Cook hopes to return to his tour later this week after canceling two shows "to deal with personal family matters."

The singer did not elaborate in the announcement posted on his Web site. But Cook's brother Adam has been battling brain cancer for over a decade, and Cook's rep tells PEOPLE that David spent time with Adam last week.

Cook, 26, who canceled college campus shows Monday and Tuesday in New Hampshire and Connecticut, will appear on Idol in a taped performance Wednesday. He is planning to get back on the road Thursday, his rep says. Concert dates are currently scheduled through October.

"David would like everyone to rest assured that we are working with the universities to reschedule the shows that are missed," says his site. Fans, meanwhile, posted hundreds of messages of support. "Take as much time as you need," wrote one. "My prayers are always with you and your amazing family."