This is a delicate tightrope to tread. Beth Vyse is known for extravagant stupidity, with over-the-top props and a full-on performance, fully committed to her surreal madness. But this year’s show is about her diagnosis with breast cancer, which is not immediately suited to any of that.

She makes a good fist of putting silliness into the story while being respectful to a sensitive issue that affects so many others, not just herself. Yet there’s also a sense that she’s holding back, not quite confident whether to be weird or to be truthful, so vacillates, not sticking to one path.

That’s entirely understandable, given that she’s only recently started feeling OK to talk about the mastectomy she had, but means there’s a feeling that there’s a new, improved version of this still-ragged show waiting in the future.

Vyse was diagnosed at 29, a soberingly early confrontation for someone just finding her way in life. At the time she had performed with the Royal Shakespeare Company (and had an odd one-night stand with a future Dr Who, by her account) and recently started a new relationship with a supportive fella who, for the purposes of this story, was Michael Jackson.

It is he, played by an audience member in a Jacko fright mask (an a particularly uncomfortable-looking audience member at this performance) who provides the comic relief. That and a few big, daft set pieces, including the introduction when Vyse greets us in the guise of Dolly Parton, screaming at us that performance is her dream, as she sloppily distributes ping-pong balls to the crowd.

Such oddness sits cheek-by-jowl with the true story, preventing it from getting too sombre. Though it also feels we don’t quite get to know the other key players – namely her parents – well enough for the sense of the story.

Slapstick surrealism aside, there’s also a gallows humour to some of the extreme situations she found herself in, too, not least when it came to discussing a replacement for her lost breast, which Vyse exploits without gimmick (well, almost).

Holding all this together is quite the task, and Vyse has the verve, charisma and honesty when it’s needed to get the job done, keeping the performance loose but the tale on track. Yet it also feels another leap forward away from being a fantastic show, which probably rests on deciding more definitely what tone to take.