Mr Trotman has revealed he’s doing well almost a year and a half on from this shock diagnosis, a charity has said.

The man from Sussex was diagnosed with glioblastoma – an invasive growth of cells in the brain – in October 2022.

One month later, he took part in a clinical trial, which had to close due to a lack of recruitment, that involved giving immunotherapy to glioblastoma patients before the current standard treatment of either surgery, radiotherapy or chemotherapy.

He had a poor reaction to the treatment from the trial that left him in hospital before he returned home in December of that year.

Brain scans last summer and more recently showed no evidence of high-grade disease in his tumour, which he was told was “unheard of” at his stage of treatment.

He started standard treatment last January and now continues with monthly chemotherapy.

Mr Trotman, an investment banker for JP Morgan, said: “We obviously don’t know what the future holds but having had the immunotherapy treatment and getting these encouraging scan results has given Emily and I a bit of hope.”

The trial was led by Doctor Paul Mulholland, a brain cancer specialist at University College Hospital in London.

Doctor Mulholland told The Times: “The standard treatment for glioblastoma is to have surgery, radiotherapy and chemotherapy. Then your disease comes back, then you have palliative care, then you die.

“It’s the same story every time. We need to do something different.”

Mr Trotman’s wife, Emily, said the treatment was “a lucky break in an otherwise devastating situation”.

She added: “We were grappling with the fact that Ben had gone from being apparently perfectly healthy to having months to live.

“Had we not met Doctor Mulholland, that would have been it for us.”