The Jonas Brothers have all undergone DNA testing for cancer after their father's battle with the disease.

Kevin Jonas, Sr. was diagnosed with stage two colon cancer in March, 2017 and he subsequently underwent surgery and six months of chemotherapy treatment.

His eldest son Kevin and brothers Joe, Nick, and Frankie all rushed home to be around their parents in North Carolina and now the brothers are using the scare to get serious about their own health and mortality.

"For me as a dad, I look at it like, 'How would my family feel, my children feel, if I had to be in this position?' I would want them to be taken care of," Kevin Jonas tells People magazine. "There are a lot of things you can't control - you've got to be prepared for anything that could come your way.

"A big thing for me is going to the doctor and getting regular check-ups, taking care of yourself, and making healthy choices."

And Kevin, Sr is so worried about his sons, he has forced them all to sign up for colorectal cancer screenings.

"I want them all to get tested as early as possible," he says. "We do have testing now that's available, and our kids will all go in and be tested and probably go in early and actually have a colonoscopy early.

"I think that Kevin is planning to (go) soon. He just turned 30. I have real concerns. (It's best to) go ahead and eliminate the issue and get in before it's an issue!"

Kevin and his brothers have already undergone DNA testing to check for pre-cancer or cancer growths and they appear to be in the clear.