Doctors told him yesterday more biopsies were needed before he would know if it was worth fighting the malignant growth in his oesophagus.
Whether the diagnosis is terminal or not, tonight he will open his Dunedin Fringe Festival show, a one-man black operetta, based on the lives and stories of the women killed by Jack the Ripper.
Four weeks ago, the Dunedin musician - know by the stage name Dr Marigaux - was diagnosed with oesophageal cancer.
Yesterday, he thought he would learn if it could be fought with aggressive chemotherapy, radiation and surgery or if he should instead focus on making the best of the time he had left.
"They're aiming for a cure, but a cure isn't that likely and so maybe they'll say we might as well make your time on the planet better by not giving you such heavy doses of chemo.
"The prognosis isn't very good any way it comes out."
What started out as a dark comedy about the man or men who might have been Jack the Ripper morphed into a show about his victims and has, since the diagnosis, become much more self-reflective.
"I was playing for some of my friends and the first words of the song were 'I could have had a life' and I thought hang on, this isn't about a woman who died a 140 years ago, it's about me, it's sort of become personal now - I've got my own Jack the Ripper inside my chest."
By focusing on the victims instead of the man who committed the murders, Davison hopes to show they were living, breathing people with stories to tell, not just another number.
On stage, a feeding tube running through his nose is the only hint that something is not quite right.
"Maybe I'm not quite as powerful as I used to be but there's not much difference and playing the bass - I'm usually a saxophone player - is no harder with the problems I've got."
• JackS the Ripper opens tonight at 8pm at the King George Hall in St Leonards.
