Spot checks can be a skin cancer lifesaver

Self-checks and seeing a doctor are the best ways of detecting deadly melanoma early, say the Cancer Society and skin specialists.

Melanoma screening with specialised photographs of moles and other lesions, such as offered by the company MoleMap, receives a cooler response from some.

Their comments follow the publication of statistics showing a rising incidence of melanoma - New Zealand has one of the world's highest rates - and wide regional variations.

These variations are linked to regional age differences, because melanoma is more prevalent in older age groups; ethnic differences, since those with fair skin are at greater risk; and climatic differences, as melanoma is associated with the amount of exposure to sunlight.

Melanoma, linked to sunburn, is the most dangerous skin cancer, but is usually curable if detected early. Each year about 1600 cases are detected in New Zealand and 250 to 300 people die from the disease. But the number of deaths may be stabilising, despite the rising incidence, because of earlier detection.

An Otago University cancer researcher, Associate Professor Brian Cox, said most of the apparent increase in melanoma cases was due to more accurate recording since statutory notification of cancer was introduced in 1994.

A melanoma check by a GP costs unsubsidised adults about $50. Skin specialists (dermatologists) charge $100 to $300.

MoleMap charges $225 for initial photos of significant moles and lesions, which are viewed by a dermatologist, who notifies the patient's doctor of any possible problems. Follow-up photographs start at $170, depending on the number of moles imaged at first. High-risk patients are recommended to have rescreens yearly; those of lower risk, with only a few moles, once every four or five years.

The company says its false positive rate is far lower than found in a study of Australian GPs' melanoma diagnoses.

Dermatological Society president and skin specialist Dr Nick Birchall advocates self-checks, and seeing a GP, or preferably a dermatologist, about any concerns.

He said services such as MoleMap were a valid adjunct for people at higher risk of melanoma. They include those with a family history of melanoma and people with a lot of moles or freckles larger than 6mm in diameter that have an irregular shape and are multicoloured.

Early melanoma signs include any spot that changes in size, colour and shape. Later signs include a spot, freckle or mole that is itchy, tender, bleeds or has a crust.

Society secretary and specialist Dr Louise Reiche said mole-mapping was useful, but self-checking, as explained by a dermatologist, was the best first defence.

The Cancer Society does not endorse dermoscopy, the service provided by MoleMap and others. It says it is unaware of studies showing that routine screening of people without symptoms reduces deaths from melanoma.

Spokeswoman Wendy Billingsley said people who had dermoscopy might feel reassured and stop checking themselves, missing a newly visible melanoma.

Hamilton dermatologist Dr Marius Rademaker said doctors had largely stopped offering free spot checks, partly because of anxiety about missing some melanomas and since it attracted mainly the "worried well".


Regional melanoma rates

Average number of cases diagnosed annually, 1992-2001, per 100,000 population

* Northland 47.92
* Waitemata 42.36
* Auckland 38.38
* Counties Manukau 31.38
* Waikato 42.33
* Bay Of Plenty 45.20
* Lakes 29.70
* Tairawhiti 34.04
* Taranaki 40.00
* Hawkes Bay 48.63
* Wanganui 42.42
* Mid-Central 51.55
* Hutt Valley 35.56
* Capital & Coast 24.19
* Wairarapa 47.37
* Nelson-Marlborough 39.34
* West Coast 39.39
* Canterbury 39.86
* South Canterbury 42.59
* Otago 41.81
* Southland 20.75
* NEW ZEALAND 39.15

Source: Health Information Service