Kiwi experts shining light on skin cancer
Updated: Sep 21, 2020
Medical researchers lead study to fight aggressive tumours
It’s that time of year when we relish the thought of summer, plan weekends in the garden, get out on the boat, go to the beach, play sports. It is also the time of year when we are much more susceptible to skin cancer through sun damage.
And anecdotally, this summer it is likely that people will die from what medical researcher Dr Cherie Blenkiron describes as “an uncommon form of skin cancer” – Merkel cell carcinoma (MCC).
“A lot of research has been done in the US and Europe and they have identified that in about 80 per cent of the tumours they looked at, there is a virus that is causing the tumour. The remainder are triggered by UV light exposure,” Cherie says. “Yet in New Zealand that prevalence is flipped on its head, there is a higher incidence of the UV triggered tumours – 71 per cent are directly caused by UV light.”
On average, 45 people in New Zealand are diagnosed with MCC each year, and for half of those, it will have already spread to different sites on the body. Fifty per cent of those diagnosed with MCC – usually aged 50+ – will have tumours so aggressive they will not survive, as the tumour is fast-growing and quickly becomes harder to treat.
While the average age of a MCC patient is 77, some as young as 29 have been diagnosed. Cherie and her team, members of the NETwork! project at the University of Auckland’s Faculty of Medical Health Sciences, are using leading-edge technology to research tumour samples to try to find better ways to treat MCC, especially those caused by the country’s harsh UV light.
These two environmental triggers themselves – a virus or UV light can be the downfall for the tumour, causing an immune response or white blood cell attack. The tumour can however overcome this attack by camouflaging itself by switching on so-called “immune checkpoints”.
This is where new immunotherapies, such as the melanoma treatment Keytruda, can be used to reawaken the immune cells.
To understand whether people with MCC could benefit from immunotherapy, Cherie and her team are working to identify the types of immune cells present in these tumours and decipher their molecular camouflage signals.
“MCC creates foreign material in the cells and the immune system goes to fight it. In patients where the tumour spreads or they cannot beat the disease, we think the immune system is being switched off.
“With funding from AMRF (Auckland Medical Research Foundation), we have been investigating different immune checkpoints, using technology that nobody has used in New Zealand before."
“This allows you to use a very small amount of the tumour to investigate about 40 different immune proteins in one go, which is very exciting. “Our trials are looking for new immune checkpoints that could be targeted with drugs that will successfully treat these patients. We have identified other potential checkpoints that look interesting, but you answer one question and then another 20 emerge – so the research is ongoing.”
The samples were sent to Seattle for analysis and the data provided in about eight weeks – “an unusally quick way of doing science”, Cherie says. “We have secured funding to send some more samples to Seattle to be tested using this novel technology.”
This ground-breaking work has been funded by AMRF, through support from a family fund in memory of their brother, and more of this type of funding is needed to improve outcomes for people with cancer.
Patients will often notice a red lump, in areas of the body that are exposed to the sun - partlcularty the head and neck. But they can occur on any part of the body -arms, legs, torso.
It won't be itchy but can grow quickly.
It is often in people aged 50+, but not always. Prevention is better than treatment and Chere recommends Kiwis practise sunsmart principles, and always protect themselves from the sun.
"Keep an eye on your skin," Cherie says, "and if you notice anything unusual see your GP."
“Merkel cell carcinoma is aggressive and non-discrimatory and we need to continue to find ways to treat it,” Cherie says. The research we do could be transferable to other cancers as well as significantly benefitting MCC patients in New Zealand, and around the world.”