Researchers have discovered that a strain of the common cold virus could be lethal to cancer cells in patients with bladder cancer.
A particular strain of the cold virus was shown to have led to the disappearance of all signs of cancer in one patient, with another 14 showing evidence that cancer cells had died.
The common cold virus could cure cancer, scientists say, as a "revolutionary" treatment was found to eradicate the disease in a week.
Scientists said they were "very excited" about the findings, for patients with bladder cancer, which could also bring hope to those suffering from other major forms of the disease.
Non-muscle invasive bladder (NMIBC) is the 10th most common cancer in the United Kingdom, with around 10,000 new cases each year.
Authors pointed out that current treatments for this cancer are problematic - a common option is an invasive procedure called transurethral resection that removes all visible lesions but has a high recurrence rate from 50%-70%.
And constant, costly monitoring is needed to check that the cancer has not returned after treatment.
During this pioneering study fifteen NMIBC patients, one week prior to pre scheduled surgery to remove their tumours, received CVA21 via a catheter in the bladder.
When examining tissue samples after surgery the team found that the virus was highly selective and only targeted cancerous cells in the organ while leaving all other cells intact.
"The virus gets inside cancer cells and kills them by triggering an immune protein - and that leads to signalling of other immune cells to come and join the party", he said.
When the scientists analyzed the patients' tissue samples after surgery, there were no traces of cancer cells in the bladder. These "hot" tumours are more likely to be rejected by the immune system.
Bladder cancer expert Dr Mark Linch, of the Cancer Research UK Cancer Institute, said the initial results were "encouraging". The immunotherapy treatment Bacille Calmette-Guerin has also been found to have serious side effects with one third of patients not responding to the treatment at all.
Dr Nicola Annels, a research fellow at the university, said it could "signal a move away from more established treatments such as chemotherapy".
Allen Knight, chairman of Action Bladder Cancer UK, said bladder cancer cost the NHS more per patient than almost every other cancer, because of the high recurrence rate.
They called the findings of the limited study potentially breakthrough.
"If the safety, tolerability, and efficacy data can be confirmed in larger clinical studies and trials, then it could herald a new era in the treatment for non-muscle-invasive bladder cancer patients, like me, who often feel that innovations in cancer therapies pass us by".