The singer and his wife Luisana Lopilato confirmed the sad news of their three-year-old's diagnosis last month , after it was first reported in the La Nacion publication in the model's native Argentina.
Luisana's sister Daniela subsequently revealed the boy is battling liver cancer.
Read more: Michael Buble and wife Luisana ‘broken in half’ by son’s cancer diagnosis
Noah began chemotherapy treatment in the U.S. in a bid to shrink the tumour, and now local reports in Luisana's native Argentina suggest doctors are hoping they will be able to operate on the toddler at the end of the year 2016.
According to the Daily Mail, medics will perform another biopsy later this month before moving ahead with the planned surgery.
Michael and Luisana have not commented on Noah's condition since announcing their eldest son's health crisis and asking for privacy.
Read more: Michael Bublé welcomes baby boy with beautiful photo tribute
"At this difficult time, we ask only for your prayers and respect for our privacy," they wrote in a statement posted online in November, 2016. "We have a long journey in front of us and hope that with the support of family, friends and fans around the world, we will win this battle, God willing."
Buble also put his career on hold to support his boy, pulling out of a performance at the upcoming BBC Music Awards in London so he can remain in the U.S.
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He is still scheduled to host the BRIT Awards in London in February, 2017 and the Juno Awards in his native Canada in April, 2017.
Michael and Luisana are also parents to son Elias, who will turn one in January, 2017.
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