After millennia of causing mild misery, the common cold virus is giving something back to humanity. A pioneering study has shown that a strain of the common cold virus can infect and kill bladder cancer cells.
Reported in the journal Clinical Cancer Research, scientists at the University of Surrey in the UK have treated 15 people with non-muscle invasive bladder cancer using a live strain of coxsackievirus, or CVA21, which typically causes mild flu-like symptoms. They were given an infusion of the bug through a catheter before undergoing surgery to remove and examine the tumors.
During surgery, one week after infusion, there was evidence that the virus had targeted and killed cancer cells in the bladder while leaving all other cells intact. In fact, one patient had no trace of cancer left anymore.
While this study is small in size and further research is required, it holds hope for new treatments against non-muscle invasive bladder cancer, which can often prove tricky to treat.
"Non-muscle invasive bladder cancer is a highly prevalent illness that requires an intrusive and often lengthy treatment plan. Current treatment is ineffective and toxic in a proportion of patients and there is an urgent need for new therapies,” Hardev Pandha, principal investigator of the study and professor of Medical Oncology at the University of Surrey, said in a statement.
"Coxsackievirus could help revolutionize treatment for this type of cancer. Reduction of tumor burden and increased cancer cell death was observed in all patients and removed all trace of the disease in one patient following just one week of treatment, showing its potential effectiveness. “
“Notably, no significant side effects were observed in any patient."
The treatment works by the virus infecting the cancerous cells and replicating itself, causing the cells to burst and die. The virus also helps to spark “immunological heat” in the affected area. Tumors in the bladder often do not have immune cells so the body doesn’t always flag the cancer. The cold virus causes the infected tumors to inflame, sounding the alarm to the patient’s own immune system.
A virus that preferentially infects and kills cancer cells is known as an oncolytic virus. Scientists first came across them in the late-1800s after noticing some patients with cancer go into remission, often only temporarily, after a viral infection.
The first oncolytic virus to receive FDA approval was a genetically modified form of a herpesvirus to treat melanoma. They continue to show promise as a cancer treatment and are currently being studied in clinical trials for a number of cancers, including bladder, prostate, colorectal, ovarian, lung, breast, and more.
“Traditionally viruses have been associated with illness however in the right situation they can improve our overall health and wellbeing by destroying cancerous cells. Oncolytic viruses such as the coxsackievirus could transform the way we treat cancer and could signal a move away from more established treatments such as chemotherapy,” concluded Dr Nicola Annels, research fellow at the University of Surrey.