Melanoma On The Rise Among Young Women In The US

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Main Category: Melanoma / Skin Cancer
Also Included In: Cancer / Oncology;  Women's Health / Gynecology
Article Date: 11 Jul 2008 - 12:00 PDT

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A review of 30 years of surveillance and epidemiological records shows that incidence of melonoma, the most lethal form of skin cancer, is increasing among young Caucasian women but not among young men in the US. The reviewers did not establish if this is due to increased exposure to ultraviolet radiation or some other factor and suggested this should be investigated further.

Led by Mark Purdue of the National Institutes of Health, the study is published in the 10th July advanced online issue of the Journal of Investigative Dermatology.

Purdue and colleagues said that recent studies had shown that incidence of non-melanoma skin cancer was rising in young adults, and in young American women in particular and they wanted to find out if the trends were similar for melanoma, a more deadly form of skin cancer.

Some studies suggest that melanoma incidence has been rising for older Americans for several decades, but that for younger adults the figures for those born after 1945 have been stabilizing. But a 2001 study of data from SEER, the Surveillance, Epidemiology, and End Results Program, covering incidence rates from 1973 to 1997, showed there was evidence of a rise in melanoma incidence in women born after 1960. So Purdue and colleagues extended that analysis to include a further 7 years of data, taking it from 1973 to 2004.

Purdue and his team looked at data on melanoma incidence among Caucasians captured in nine SEER registries since 1973. These included records from Atlanta, Connecticut, Detroit, Hawaii, Iowa, New Mexico, San Francisco-Oakland, Seattle and Utah. They calculated the age-adjusted incidence of invasive cutaneous melanoma and deaths due to the disease among among men and women aged 15 - 39 years.

Using recognized statistical software published by the National Cancer Institute, they assessed various types of trends and how they progressed successively over the decades involved.

The results showed that:

• The overall age-adjusted annual incidence of melanoma among young men went up from 4.7 cases per 100,000 persons in 1973 to 7.7 per 100,000 in 2004.


• The overall rise among young women over the same period was much steeper, from 5.5 in 1973 to 13.9 in 2004.


• And the shape of the trend over that period was also different for young men than for young women.


• Around 1980, the annual incidence trend for men levelled off and remained stable right through to 2004, but for young women, the annual incidence rate went down from 1978 to 1987, stabilized from 1987 to 1992, and then increased again.


• Incidence of both thinner and thicker melanomas among women from the 1990s onwards went up and was greater for regional and distant tumors than localized lesions.


• Deaths due to melanoma among young men and women went down from 1981 onward.

Reflecting on their results, Purdue and colleagues wrote that it was important to consider whether these patterns reflected changes in data quality, diagnosis or surveillance rather than what was really happening in the population. For instance, there is evidence of underreporting in SEER going up over time (perhaps as much as 17 per cent of cases in two of the registries), but this would not explain the increased incidence among young women.

A change in the way melanoma is diagnosed would not affect the findings said the investigators, because it doesn't explain the gender differences in the trends.

Earlier detection due to changes in screening methods may explain the higher rate of increase among superficial localized tumors compared to thicker lesions and more advanced forms of the disease, and the decrease in mortality after 1981 is consistent with earlier detection and increased surveillance.

But, the analysis showed that the increasing trend among young women from the early 1990s was also found to be in incidence of thicker and more advanced tumors, which are less susceptible to mis-diagnosis and incorrect classification, wrote the researchers, plus, after adjusting for age and period effects (to eliminate things like changes in surveillance methods), they maintain that their figures show a robust indication of "changes in disease risk factor prevalence across birth cohorts".

Thus Purdue and colleagues appear reasonably confident that their figures show a real trend of increasing incidence of melanoma among young women although they cannot rule out an effect due to changes in surveillance.

Speculating on causes, they said the pattern reflects reported trends in increased exposure to ultraviolet radiation, the main cause of melanoma, and reported figures that show sunburn is on the increase among American adults overall, although these do not show trends by age group.

However, among 16 to 18 year-olds, both the prevalence of sunburn and the average number of days spent at the beach went up between two sun surveys carried out in 1998 and 2004, and tanning bed use, which has been cited recently as a probable cause of melanoma is also going up among US adults and young women in particular.

Purdue and colleagues concluded that:

"Our analysis of SEER data suggests that melanoma incidence is increasing among young women."

They suggested further studies were needed to establish whether the increasing trends (for melanoma and non-melanoma skin cancers) were caused by changes to exposure to ultraviolet radiation or not.

"Recent Trends in Incidence of Cutaneous Melanoma among US Caucasian Young Adults."
Mark P Purdue, Laura E Beane Freeman, William F Anderson and Margaret A Tucker.
Journal of Investigative Dermatology advance online publication 10 July 2008.
DOI: 10.1038/jid.2008.159

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Sources: journal article.

Written by: Catharine Paddock, PhD
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