Following the diagnosis last year, Buble cancelled all work commitments but remained on board as presenter of this year's ceremony. However, he has since changed his mind, deciding instead to direct his entire focus on caring for his son.
Noah is currently undergoing chemotherapy with doctors giving him a 90% chance of survival.
“He will always be welcome at the BRITs but it’s important that he is with his family. It would not look good to be singing and dancing on stage while his son is so ill.”
It is unknown who organisers are eyeing as a replacement; over the last two years, the event has been hosted by TV personalities Ant and Dec while The Late Late Show's James Corden oversaw proceedings in 2014.
The 2017 BRIT Awards take place at London's 02 Arena on 22 February and, among other things, will feature performances from Little Mix and Emeli Sande as well as extensive tributes to late musicians David Bowie and George Michael. The nominations were announced last weekend.
Buble, 41, has one other son - one-year-old Elias - with model wife Luisana Lopilato.
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