Overall survival for patients with multiple primary melanomas was 31% worse compared to those with a single primary melanoma, a retrospective study from the Netherlands found.
Looking at data from close to 57,000 patients from the nation's cancer registries, 36.8% of these second primaries were found within the first year of an initial diagnosis while 27.3% were found after 5 years of follow-up, reported Mary-Ann El Sharouni, MD, and colleagues from University Medical Center Utrecht in the Netherlands.
"The findings suggest that current melanoma follow-up strategies need to be reconsidered for patients with multiple primary melanomas and guidelines should comment on this," they wrote in .
The retrospective study looked at adults with primary, invasive cutaneous melanoma diagnosed in the Netherlands from 2000 to 2014, with a median follow-up of 75.1 months.
The survival analysis compared data from 1,767 multiple primary and 37,049 single primary melanomas. Corrected for all variables, the hazard ratio for death was 1.31 for those with multiple primaries (95% CI 1.20-1.42, P<0.001).
Presence of ulceration (HR 2.20), Breslow thickness (HR 1.11 per mm), and increasing age (HR 1.06 per year) were all significantly associated with worse survival for these patients.
"Because patients with multiple primary melanomas had worse survival than patients with a single primary melanoma in our multivariable analysis, we believe that a patient, once proven to have developed a second melanoma, may benefit from more thorough surveillance," El Sharouni's group wrote.
Having one melanoma increases a person's risk for having another, Jennifer Stein, MD, PhD, associate professor of dermatology at NYU Langone Health in New York City, told ľֱ.
"The second melanoma can occur anywhere on the body and can develop in a completely different part of the body from the first melanoma," Stein said, noting that if found early it is completely curable.
In addition to the finding of increased risk for death among those with more than one melanoma, another important finding was that the additional melanomas were usually thinner than the original melanoma, said Stein, who was not involved in the study.
The researchers found a significant decrease in median Breslow thickness from first melanoma to subsequent melanomas (0.90 vs 0.65 mm, P<0.001), a finding that suggests increased dermatologic surveillance after the primary diagnosis, they noted.
"Thinner melanomas are less likely to spread to other parts of the body than thicker melanomas, so it is important to find melanomas early, when they are as thin as possible," Stein said. "This article reminds us of the importance of regular skin exams for patients who have had melanoma."
In the overall study cohort (N=56,929), there were 54,645 single primary melanomas and 4,967 multiple primary melanomas (from 2,284 patients).
The incidence of multiple primary melanomas was 4%, with men more likely to have multiple primaries than women (49.6% vs 43.7%, P<0.001).
About half of second melanomas (48.7%) had the same T stage as the primary diagnosis -- 16.2% had a higher T stage, and 35.1% had a lower T stage (P<0.001).
Disclosures
El Sharouni and colleagues reported no conflicts of interest.
Stein reported no conflicts of interest.
Primary Source
JAMA Dermatology
El Sharouni MA, et al "Comparison of survival between patients with single vs multiple primary cutaneous melanomas" JAMA Dermatol 2019; DOI: 10.1001/jamadermatol.2019.1134.