Taking the misery out of melanoma
After years of fear, there is finally some genuine good news about melanoma – and it applies to about 70 per cent of patients who are diagnosed with an invasive melanoma… if diagnosed early.
This group has thin melanomas that are no thicker than a millimetre.
A large study has shown that with appropriate treatment, they have a 96 per cent chance of surviving their cancer.
And this doesn’t mean the usual five-year survival, it means 20 years.
“These results take the sting out of invasive melanoma for the majority of people diagnosed these days,” says the study’s lead author, Adèle Green.
She is professor and head of cancer and population studies at the Queensland Institute of Medical Research and hopes these results will lift some of the pessimism about melanoma.
When it comes to public awareness and early detection of melanoma, she says Australia is top of the international league tables. We are so vigilant about our skin that melanoma is increasingly being diagnosed in its earliest stages, when it is superficial and poses no threat to survival.
Her research looked at melanomas that had reached the next stage, where they are thin but slightly invasive. Although these are by far the most common invasive melanomas in Australia, they have been little studied.
This study followed 26,736 Queenslanders who each had a single thin invasive primary melanoma. Although it is cause for celebration that 20 years later some 96 per cent are still alive, Green and her co-researchers were concerned about the 4 per cent who didn’t make it.
They used the study to tease out factors that put this little group at risk of their cancer spreading.
It was a job for a large study team which included researchers from Cancer Council Queensland, the University of Queensland, the Princess Alexandra Hospital in Brisbane and the Murdoch Children’s Research Institute in Melbourne. The data came from the Queensland Cancer Registry.
Their study, published in the Journal of Clinical Oncology, has received international acclaim and been described as a blueprint for assessing thin melanomas with an increased risk of metastatic disease.
So who is at added risk of having a thin melanoma spread after treatment? Green says men are more at risk than women. The reason is not clear but may be that they tend to present later when they have already begun the silent transition to the next stage.
Even with thin melanoma, she says thickness matters. The study showed those whose lesions are more than 0.75mm are four times more likely to die than those whose lesions are less than 0.25mm in thickness.
Age matters, too. People over 65 have a threefold risk of dying of their thin melanoma compared to those under 25.
Green says the site of the melanoma is also significant. People with tumours on the head have a poorer outcome than those with melanomas on the trunk. The reason is unknown but may be partly that the lesions can drain directly into major lymph nodes.
Nodular melanomas also carry higher risk. They can be light-coloured, lacking in pigmentation, and carry more risk because they are aggressive and dive below the skin quickly, increasing the chance of early spread.
Although melanoma has been described as Australia’s “national cancer”, it seems men have it worse than women. They get invasive melanomas more often and usually do less well.
In Queensland between 2000 and 2008, some 11,635 invasive melanomas occurred in men and only 7985 occurred in women. Green’s advice to men after their thin melanoma has been treated is to continue to be vigilant, especially for the first 10 years.
She says the value in the study is that doctors can now reassure 70 per cent of patients with invasive melanomas that their risk of dying from their cancer is very small.
An accompanying editorial in the journal describes this study as seminal research about the natural history of melanoma.
The data were unique because they came from a population-based registry which better represents melanoma survival than reports based on data from major melanoma treatment centres which have a more selective referral of people with high-risk disease.
Ian Olver, CEO of Cancer Council Australia, says the major message from this study is the importance of early detection of melanomas when they are still thin and have such a high cure rate.
“We need to reinforce that people should be aware of what their skin looks like and any change in a spot on the skin, such as growth, itch, change in colour or bleeding, should be reported immediately so it can be assessed,” he says.
“If treated early when the melanoma is thin, the outcome is excellent.”
The other message is that we can identify a group of melanomas which will do very well with local surgery only and do not need more extensive treatment.
Source: Jill Margo – The Australian Financial Review