Today, he is back to being the "bossy and independent and stubborn" boy he was before cancer entered their lives.
"He's back to being a normal 6-year-old boy."
In remission now, Asante is in the maintenance phase of treatment with oral chemotherapy every night and trips every three months to Auckland for check-ups. It will last the next two-and-a-half years.
The family's life is still affected by the cancer - trips to crowded places like the movies or malls are off limits - but they're learning to live their new normal - thanks partly to the support of the foundation.
Thanks to them, Asante has more than 400 beads; a visual reminder of all the nights in hospital, days of chemotherapy, lumbar punctures, bone marrow aspirations, needle pricks, the nasal gastric tube and helicopter rides.
Ms Lang said cancer never crossed her mind when she took her son to hospital with a 40.9C temp that New Year's Eve.
But, within hours they had that diagnosis, and he had several hours of blood transfusions before he was flown to Starship Hospital to begin the treatment.
Ms Lang said she felt "so grateful he had five years of healthy life" beforehand and was too young to understand the gravity of what he faced.
"He just goes with the flow."
The toughest part for Asante was not being able to get the promised puppy, which they had chosen, named and were ready to pick up just before the diagnosis.
"That was like salt on the wound."
For Ms Lang, her parents who they live with, and Asante's younger sister Alia, the foundation provided much needed support. "Essentially the Child Cancer Foundation has lifted me or carried me at times of complete and utter despair. The foundation has been an absolute rock - both emotionally as well as financially through assistance with grocery and travel costs."
Ms Lang said family support co-ordinator Barb Richardson's assistance had been instrumental - knowing what to say and ask, as there was "no guidebook". It also helped connect them to other families and organise events like the "special boys' day out" to create positive memories, as well as helping Alia.
She said the support of everyone - from childhood friends to her workplace at Bay of Plenty police headquarters - had been huge in helping.
Ms Lang said the experience had taught her you didn't know what was around the corner, but for now, Asante was into his second term at Lynmore School and his bloodwork was good. And, the family has finally got that much-anticipated puppy.
How to donate:
* Annual street appeal will take place on Friday and Saturday.
* To make an instant $3 donation text HELP to 833.
* Visit www.childcancer.org.nz to donate
* It is a stand-alone charity which receives no direct government funding.
