Melanoma Trends: Unearthing Sex-Specific Patterns Over 36 Years
Conexiant
June 19, 2024
The study, published in The Journal of Investigative Dermatology, utilized age-, sex-, and site-specific data on invasive melanoma cases retrieved from cancer registries. The data spanned 36 years and included 4 anatomic sites: head and neck, trunk, upper limbs, and lower limbs.
The study revealed statistically significant increases in melanoma incidence across all body sites in both sexes, except for trunk and lower limb melanomas among Queensland women. In 2018, melanoma incidence among men was highest on the trunk (35.86 per 100,000 in Queensland, 14.67 per 100,000 in the US, and 8.45 per 100,000 in Scotland). Among women, incidence was highest on the upper and lower limbs in the U.S. and Scotland, and on the upper limbs and trunk in Queensland.
The age-specific incidence trends demonstrated men had consistently higher rates of trunk and head/neck melanomas, with the male excess increasing steeply with age. Conversely, women had higher rates of lower limb melanomas through at least middle age. Birth cohort analyses identified turning points from high to low incidence among recent birth cohorts, occurring earliest in Queensland.
Melanoma incidence rates were not proportional across all age groups and populations, indicating significant influences of both period and cohort effects. The researchers concluded that changing patterns of UV exposure, along with possible innate differences in site-specific susceptibility, contributed to these observed trends.
The researchers employed age-period-cohort models to assess incidence trends and calculated the average annual percentage rate of change using the Joinpoint Regression Program. All incidence rates were standardized to the US 2000 standard population. The male-to-female incidence rate ratio was calculated as the ratio of the age-standardized rates per calendar year.
The authors declared no conflicts of interest.