Although there are both beneficial and detrimental effects of ultraviolet radiation (UVR), excess exposure can be damaging to health.

 Skin cancer is the most common cancer in New Zealand, with New Zealanders at high risk of developing a skin cancer during their lifetime. Our skin cancer rates are among the highest in the world. Melanoma incidence rates in Australia and New Zealand are around four times as high as those found in Canada, the USA and the United Kingdom(1).

New Zealand’s high rates of skin cancer are due to a number of factors including the strength of the UVR that reaches New Zealand during the daylight savings months, low ozone values, our outdoor lifestyle, our tendency to ‘seek the sun’, and the high proportion of people with fair skin in our population. Light skin type, large numbers of moles and excessive sun exposure (particularly intermittent episodes of sunburn), especially in childhood and adolescence, are the major predictors of melanoma risk.

Yet, skin cancer is readily preventable. Over 90% of all skin cancer cases in high UVR environments like New Zealand are attributed to excess exposure to UVR(2). That is why the Cancer Society sees the promotion of skin cancer prevention and early detection as a central component of its work. 

 About Skin Cancer

 Skin cancers include:

• Melanoma: the least common but the most serious form of skin cancer.
• Squamous cell carcinoma (SCC): easily treated if found early but can be fatal if left untreated.
• Basal cell carcinoma (BCC): the most common and least dangerous skin cancer. BCC can be serious, including surgery and scarring, if left untreated.

Skin Cancer Facts and Figures

Providing an exact figure for the number of non-melanoma skin cancers (basal cell carcinoma and squamous cell carcinoma) is difficult as, unlike melanoma, they are not required to be notified under the Cancer Registry Act 1993.  However, estimates range from approximately 45,000 (as confirmed by laboratory tests) and 70,000 annually in New Zealand(3). Non-melanoma skin cancers are often self-detected and are usually removed in doctors’ surgeries.

 In 2004, the year for which most recent figures are available, there were 1,896 melanoma registrations (949 males and 947 females)(4). Among women, melanoma was the third most common cancer after breast and colorectal cancer, and, among men, the fourth most common cancer after prostate, colorectal and lung cancers. Melanoma also accounted for 249 deaths (152 males and 97 females).

 Like other cancers, melanoma occurs most often in older people, but can also affect younger people. Among males, 25 to 44 years, melanoma was the leading cancer site (122 registrations), and the cause of 17 deaths in 2004. For females aged 15 to 24 years, melanoma was the most common cancer (12 cases).

For Maori, there were 17 melanoma cases registered (5 males and 12 females) and 6 deaths recorded (4 males and 2 females) in 2004. Melanoma rates may be increasing among Maori, although rates based on small numbers are unreliable. 

Skin cancer has been estimated to cost the NZ health system in excess of NZ$33M per annum(5). The personal costs can be significant, often involving surgical intervention.

References

1. International Agency for Research on Cancer. IARC Monographs on the evaluation of carcinogenic risks to humans. Solar ultraviolet radiation. Lyon: International Agency for Research on Cancer, 1992.
2. Armstrong BK. How sun exposure causes skin cancer. In: Hill D, Elwood JM, English DR, Eds. Prevention of Skin Cancer. Dordrecht: Kluwer Academic Publishers, 2004.
3. O'Dea D. The costs of skin cancer to New Zealand. Wellington: Wellington School of Medicine, University of Otago, 2000.
4. New Zealand Health Information Service. Cancer, New Registrations and Deaths. Wellington: New Zealand Health Information Service, 2007. www.nzhis.govt.nz
5. O'Dea D, 2000, as above.

 

Further information