PEOPLE diagnosed with a deadly form of cancer will no longer face the prospect of having a needle inserted into their eye thanks to a new blood test.
About 150 Australians a year are diagnosed with uveal cancer, a deadly type of melanoma that attacks the eye first and then spreads to the liver.
In about half of cases the tumour will metastasise throughout the patient's body, resulting in a life expectancy of less than two years.
Now researchers at Edith Cowan University have developed a blood test that can determine the risk of a patient's cancer spreading throughout their body - without the need for an invasive biopsy.
Lead researcher PhD student Aaron Beasley, from ECU's Melanoma Research Group, said the blood test would provide a number of benefits.
"Previously, the only way to determine if the cancer was likely spread to other parts of the body was to take a biopsy sample, which involved inserting a needle into the patient's eye - in some cases while they remain conscious, which is not a pleasant experience," he said.
"Additionally, this blood test can provide clinicians with a clearer picture of the disease progression in those patients whose cancer has metastasised."
Circulating tumour cells
Joint lead researcher Elin Gray, a Cancer Research Trust fellow, said the blood test measured the amount and type of circulating tumour cells (CTCs) and circulating tumour DNA (ctDNA) in the blood.
"CTCs are cells that have been shed from the primary tumour and are carried in the blood, while ctDNA is fragments of DNA that has broken away from the tumour," Dr Gray said.
"By analysing the genetic makeup of these CTCs we were able to give an accurate prognosis of whether the patient's melanoma was likely to metastasise throughout their body.
"Additionally, we found that in patients whose uveal cancer was spreading, the amount of ctDNA in their blood gave an indication of how far the cancer had spread. So ctDNA analysis could be a minimally invasive way of monitoring the disease progression in patients whose cancer has metastasised."
Clinical use
Mr Beasley said the combination of CTC and ctDNA analysis could have significant clinical applications.
"What we envision is that CTC analysis could be used clinically to stratify uveal melanoma patients into high and low risk categories," he said.
"Then a ctDNA test could be used to monitor disease progression and provide clinicians with valuable information to better make decisions for their patients."
Personal view of eye cancer
THE first indication Perth man Peter Samson had that something was wrong was when he had trouble reading text on his computer.
"I was sitting at home and I remember trying to read something on my computer. It felt like a curtain was being pulled across my vision," he said.
"I thought I had a detached retina so I went straight down to my optometrist. It was only when he told me to go straight to an eye cancer specialist that I realised I may be facing something quite serious."
The specialist discovered a 12mm by 6mm melanoma tumour in his right eye.
"I woke up in the morning feeling pretty healthy, and less than 24 hours later I was dealing with what could be an incredibly aggressive cancer," he said.
Mr Samson avoided the daunting prospect of a biopsy while conscious. Instead, a sample was taken during surgery on the melanoma.
Nevertheless, there was a considerable delay in receiving the biopsy results.
"I then had to wait six weeks for my biopsy to be examined in the UK before I got my results.
"The uncertainty was difficult, but I tried to put it to the back of my mind as much as I could."
Mr Samson was lucky -his uveal melanoma was not the type that spread aggressively and he has since made a good recovery.
"Being able to tell people more quickly what they are facing with a blood test will definitely make a difference for people at a very difficult time," he said.
Clinical Application of Circulating Tumour Cells and Circulating Tumour DNA in Uveal Melanoma was recently published in the Journal of Clinical Oncology - Precision Oncology.
