A strain of the common cold virus could potentially target, infect and destroy cancer cells in bladder cancer patients, British researchers report today.
Researchers from the University of Surrey and Royal Surrey County Hospital investigated the oncolytic virus coxsackievirus (CVA21 in 15 patients with non-muscle invasive bladder cancer (NMIBC).
Typical treatments for this type of cancer include transurethral resection, which is an invasive procedure that removes all visible lesions. However, it has a high tumour recurrence rate of between 50% and 70% as well as a high tumour progression rate between 10% and 20% over two to five years. Another common course of treatment is immunotherapy with Bacille Calmette-Guerin, but that has been found to have serious side effects in one third of NMIBC patients, while one third do not respond to the treatment, the researchers say.
In this ground-breaking study, which is published in the latest edition of Clinical Cancer Research, 15 NMIBC patients received CVA21 via a catheter in the bladder one week prior to pre-scheduled surgery to remove their tumours.
Examination of tissue samples post-surgery discovered that the virus was highly selective, targeting only cancerous cells in the organ and leaving all other cells intact.
The virus was found to have infected cancerous cells and replicated itself causing the cells to rupture and die.
Urine samples taken from patients on alternate days detected ‘shedding’ from the virus, which implied that once virally infected cancer cells had died, the newly replicated virus continued to attack more cancerous cells in the organ.
Following treatment, the majority of patients experienced cell death, while in one patient no trace of the cancer was found during surgery.
Hardev Pandha, principal investigator of the study and Professor of Medical Oncology at the University of Surrey, said: “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.
“Coxsackievirus could help revolutionise treatment for this type of cancer. Reduction of tumour 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.”
Dr Nicola Annels, research fellow at the University of Surrey, added: “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.”
Clinical Cancer Research 5 July 2019
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