Predictive tool to help manage NZ’s melanoma crisis
11th September 2017
A melanoma expert says a tool for general practitioners that uses just eight primary factors to predict people’s risk of developing a melanoma could identify 80 percent of melanomas and reduce deaths from the disease.
Professor David Whiteman, who heads the Cancer Control Group at QIMR Berghofer Medical Research Institute in Queensland, has told a gathering of melanoma experts in Queenstown that New Zealand can’t ignore its melanoma crisis.
“You either have to prevent new cases, which will take decades, or find the melanomas already out there and treat them early. If you don’t catch melanoma early, you have to treat it as an advanced disease and that’s very expensive and not always successful.”
Professor Whiteman leads a team that has developed a melanoma risk prediction tool for Australian GPs that uses just eight precisely weighted primary factors to predict a person’s risk of developing a melanoma over the next three years.
The tool was developed from data collected over the last four years from nearly 44,000 Queenslanders aged 40 to 69, none of whom had melanoma at the time they completed a comprehensive questionnaire on skin cancer risk factors. They were followed through the health system to see who developed a melanoma. The data of those who did was used to identify the eight primary risk factors:
1. age (older people have a higher risk)
2. gender (men have a higher risk)
3. tanning ability (those who don’t are at higher risk)
4. hair colour (fair and red heads have a higher risk)
5. number of moles they had as a teenager (the more moles, the higher the risk)
6. whether they’ve had a non-melanoma skin cancer (those who have are at higher risk)
7. family history of melanoma (higher risk)
8. whether they use of sunscreen
Professor Whiteman says a patient can complete a simple questionnaire while waiting to see their GP, who can use the tool to analyse the answers and help them then decide whether the patient needs to be screened.
He says it doesn’t mean no one in the low risk category will develop a melanoma or that everyone in the high-risk category will. “But those in the top 40 percent of risk will have 80 percent of all melanomas so it means melanomas can be prevented by targeted screening.
“It also means you don’t have to collect information on a whole lot of other things that we know are associated with melanoma but are irrelevant because they are explained by one of these eight primary factors. For example, childhood sunburns are all experienced by people with fair or red hair or those who don’t tan.”
Professor Whiteman says he was surprised that having had another kind of skin cancer identified as one of the eight primary risk factors.
“It was always thought to be a risk factor for melanoma, but in fact it’s a very strong predictor, which I don’t think is common clinical knowledge.”
The tool is being evaluated in a clinical setting and could be available for use in general practice in New Zealand within a couple of years.