Overall melanoma incidence decreasing among young patients

Key takeaways:

• The incidence rates per 1 million person-years among pediatric and adolescent/young adult patients were 1.74 and 62.05.
• The incidence of melanoma diagnoses has declined in nearly all age groups.

Researchers found various trends in melanoma incidence among young patients, one of which is that rates are steadily decreasing, according to a study.

“Presentations of melanoma in the pediatric and adolescent/young adult (AYA) subgroups are understudied in comparison to adult populations,” Bianca E. Ituarte, BA, a fourth-year medical student at the University of Missouri-Kansas City School of Medicine, and colleagues wrote. “The aim of our study is to provide an expansive and updated characterization of cutaneous melanoma in young patients across the United States.”

Using the National Childhood Cancer Registry, the researchers collected data on melanoma incidences diagnosed between 1997 and 2020 among pediatric patients (n = 1,243; age range, 0-14 years) and AYA patients (n = 74,865; age range, 15-39 years), and evaluated trends based on age, sex, race and ethnicity.

The incidence rates per 1 million person-years among pediatric and AYA patients were 1.74 (95% CI, 1.64-1.84) and 62.05 (95% CI, 61.6-62.5), respectively.

At 62.3%, more cases occurred in females vs. males. Non-Hispanic white patients also represented 87.5% of all diagnoses and experienced a significantly higher incidence rate across age groups compared with Hispanic patients (5.5%), non-Hispanic patients of unknown race (5.5%), Asian or Pacific Islander patients (0.8%), Black patients (0.5%) and non-Hispanic American Indian/Alaskan Native patients (0.2%).

Melanoma not otherwise specified/regressing was the most common subtype among pediatric (60.18%) and AYA (50.82%) patients followed by superficial spreading (16.25% and 41.26%, respectively).

Among pediatric patients, melanoma on the lower limb and hip was the most common location at 25.9%. On the other hand, the most common melanoma location in AYA patients was on the trunk at 38.7%.

By 2020, a significant decline in incidence of melanoma diagnoses was seen in all age groups except in those aged 0 to 4 years, which the authors said was most likely due to the small sample size.

The authors found children aged 10 to 14 years saw an insignificant increase in annual percent change of incidence rates prior to 2001, at which point the rate significantly dropped until 2020. For children aged 5 to 9 years, the authors reported a significant increase in annual percent change of incidence rates between 1997 and 2014, at which point there was a significant decrease through 2020.

In the AYA population, annual percent change increases in incidence rates peaked for all age groups between 2003 and 2005, but these were followed by steady and significant declines.

“This may be attributed to greater public efforts in protecting skin against excessive ultraviolet exposure during childhood compared to preceding generations, in concurrence with decreased tanning bed use, and more widespread usage of sunscreen,” the authors wrote. “It is worth noting that the observed decline in incidence rates precedes the first year of COVID-19, during which time rates of melanoma diagnoses were reportedly lower, indicating there may be other factors which explain the lower incidence during the pandemic lockdown.”

Ultimately, the authors agree that future research should be conducted to elucidate the reasons behind decreasing melanoma rates among young patients as well as improve diagnostic and treatment outcomes.