Michael Bublé's son is ''doing very well'' one year after his cancer diagnoses.

The 'Haven't Met You Yet' singer had his world turned upside down in November 2016 when his eldest son Noah, four, was diagnosed with the disease.

But now, sources have revealed that after the ''tense time'' Michael, 42, and his family - including his wife Luisana Lopilato, with whom he also has 22-month-old son Elias - experienced over the holiday season last year, they are in much better spirits this year, as Noah is being treated for his condition.

The insider told 'Entertainment Tonight': ''This time last year, the holidays were a tense time for the Bublé family. When Noah received a cancer diagnosis, Michael immediately made the decision to step away from his work. It was really a scary time for everyone.

''Noah is doing very well. He's an energetic little boy! Events like this put everything in perspective ... There's no doubt Christmas will be extra special at the Bublé household this year.''

It comes after 30-year-old Luisana revealed earlier this year that the ''worst is over'' when it comes to Noah's fight against cancer, but his parents are still trying to ''be strong'' for their boy.

She said: ''There are things that happen in life that make you realise that the most important things that you think are important, really aren't.

''The most important thing is to have faith and to be strong. There are nights that I still don't sleep and I pray to God because it's still a long process and the worst is over. Thank God.

''When I was down, my mom told me, 'Be strong, your son will be fine.'''

Noah was initially diagnosed with mumps and swollen glands before further test results discovered he had cancer, and Luisana, who was in Buenos Aires at the time, was so devastated she couldn't tell her husband over the phone so jumped on a plane to Los Angeles.

She added: ''They ran lots of tests, blood analysis, everything. When they did an ultrasound, they said they found something in his stomach. [Doctors] told us they weren't sure what it was, but it was a tumour.''