Survivors of pediatric, young adult melanoma face higher risk for second primary cancer

Key takeaways:

• Infants diagnosed with cutaneous melanoma (CM) before age 1 year were most at risk for secondary primary cancer (SPC).
• Across all age groups, CM survivors had an about 5-fold increased risk for developing SPC.

Survivors of cutaneous melanoma, especially those diagnosed at a young age, were at an increased risk for secondary primary cancers compared with the general population, according to a study.

“A second cancer diagnosis can have profoundly devastating impacts on survivors of childhood melanoma and their families,” Yen Luu, MD, of the department of dermatology at University of Missouri-Kansas City School of Medicine, and colleagues wrote. “While the incidence of primary cutaneous melanoma (CM) in children is declining and the 5-year survival rate is relatively high (87% to 95%), second primary cancers (SPCs) occur in over 11% of cases, reducing overall survival outcomes.”

In this study, the authors assessed the SPC risk in 7,169 pediatric and young adult CM survivors using data from the Surveillance, Epidemiology and End Results program. Patients (aged range, 0 to 29 years) had a first primary CM diagnosis between 2000 to 2018 and survival of at least 2 months from diagnosis.

Results showed that 8.82% of the CM survivors developed SPC, meaning CM survivors have an almost 5-fold increased risk for developing SPC compared with the general population (standardized incidence ratio [SIR] = 4.98; 95% CI, 4.6-5.38).

Across all age groups, the risk for secondary primary melanoma was highly elevated (SIR = 32.5; 95% CI, 29.7-35.6) with the 485 secondary primary melanomas comprising the majority of SPC cases. In fact, secondary primary melanomas contributed greatly to the increased risk for SPC (SIR excluding melanoma = 1.31; 95% CI, 1.11-1.54).

The incidence of SPC was highest among infants who were diagnosed with CM before age 1 year (SIR = 164; 95% CI, 19.8-592) and lowest among those diagnosed with CM between ages 25 to 29 years (SIR = 4.64, 95% CI, 4.19-5.13). However, those that received a first primary CM diagnosis between ages 25 and 29 years were the most susceptible to internal cancers.

The risk for SPC declined with age, with those aged 15 to 19 years (SIR = 45; 95% CI, 33-60) facing an increased risk vs. those aged 24 to 29 years (SIR = 30; 95% CI, 26.6-33.6).

The risk for SPC was highest within the first year of CM diagnosis (SIR = 27.5; 95% CI, 23.7-31.6), but decreased with time. After 10 or more years from initial diagnosis, the risk for SPC had a SIR of 2.27 (95% CI 1.85-2.74).

“The findings of the current study highlight the importance of regular skin exams, due to the highly elevated risk for SPM, and primary care follow-ups for any childhood or young adult survivor of CM,” the authors wrote.