Older adults, men at increased risk for second primary melanoma diagnosis

Key takeaways:

• Patients aged 40 years and younger saw longer interval times between melanoma incidences vs. patients aged 50 to 59 years and 80 years or older.
• Men experienced shorter interval times than women.

Following a first primary invasive melanoma diagnosis, older adults and men may experience a second case sooner than other patients, according to a study.

“The steep increase in the incidence of cutaneous melanoma, along with larger numbers of melanomas being diagnosed at earlier stages, and improvements in melanoma treatment have resulted in an expanding population of melanoma survivors over the past decade,” Reza Ghiasvand, PhD, senior researcher at the Oslo Center for Biostatistics and Epidemiology at Oslo University Hospital, Norway, and colleagues wrote. “These patients are at risk of developing subsequent melanomas during their lifetime, although the reported risk of second primary melanoma from different studies varies substantially.”

As a result, the researcher set out to determine the incidence rate of second primary invasive melanoma in Norway as well as the time between the first and second cases. In their population-based cohort study, the researchers compiled data on melanoma diagnoses from 19,196 adults (mean age at diagnosis, 62 years; 51% women) between 2008 and 2020.

In the year following diagnosis, results showed that the average incidence rate was 16.8 (95% CI, 14.9-18.7) cases per 1,000 person-years. During the second year, this rate decreased to 7.3 (95% CI, 6-8.5) before stabilizing.

According to the study, the median time between first and second primary invasive melanomas decreased with advancing age. In patients aged younger than 40 years, the median time between incidences was 37 months (95% CI, 8-49). This decreased to 18 months in patients aged 50 to 59 years (95% CI, 13-24) and 11 months in patients aged 80 years and older (95% CI, 7-18).

In 47% of patients, the second primary melanoma was located on the same site as the first primary, whereas it was located on a different site for 53%. Among those who had a second melanoma in the same site, men experienced significantly lower interval times (12 months; 95% CI, 7-19) than women (22 months; 95% CI, 11-35).

“The results of this cohort study may have potential implications for a more personalized surveillance of patients with melanoma,” the researchers concluded, emphasizing that this need may apply most to older patients, especially men, for at least the first 3 years after their initial diagnosis, regardless of the characteristics of their first melanoma.