One of the biggest problems that are associated with the treatment of malignant tumours is that even after successful surgery, the patient may experience a recurrence. Removal of cancerous lesions with an adequate margin of healthy tissue can reduce the risk of this occurring, but it does not completely rule out the possibility of recurrence. Scientists are therefore undertaking a search for ways to reduce the risk of cancer recurrence - one potential one is reported by specialists at the University of California, Los Angeles.