Stan Walker says some people thought he was on "crack or whatever" when his health condition became evident last year, but he bets they'll be feeling "pretty dumb right now".
The Kiwi singer made the comment in an Instagram post as he released a new trailer for his upcoming documentary detailing his serious health battles over the past year.
He hit out out at nasty speculation last year about the causes of his sudden weight loss.
"I bet half the people thinking I was on crack or whatever y'all were saying are feel(ing) pretty dumb right now," he wrote.
"Ah well, we are all know it alls sometimes & just make up stories. Its allgood," he added.
"This is bigger than all the talkers talking. It's bigger than me. Its bigger than whats happened & is happening to me. There is always someone worse off going through alot worse," Walker continued.
It's been hard for my mum, she cries everyday and she blames herself too- Stan Walker in the documentary Stan
"All im gonna say is that im blessed to be alive & well. God is good & ive been blessed with a back bone of whanau & friends that go through the highs & the lowest of lows with me. So yeah just have a watch this Sunday."
The documentary Stan follows the singer through the process of treatment and surgery for a rare cancer causing gene that runs in his family.
The gene mutation is responsible for the death of 25 members of his family.
It is understood that Walker has had his stomach removed as a result.
The genetic mutation estimated to cause stomach cancer by the age of 40 in 70 per cent of the people who have it.
The trailer features Walker's mother caring for him in hospital.
"It's been hard for my mum, she cries everyday and she blames herself too," Walker says.
"What if there's complications, that's how I die."
The trailer also features an interview with his mum.
"I'd rather me go before my children, anyone would, any mother and father would," she says.