WEDNESDAY, June 7, 2023 -- Patients with melanoma in situ (MIS) have higher relative survival and lower all-cause mortality than the general population, according to a study published online June 7 in JAMA Dermatology.

Vishal R. Patel, from Dell Medical School at the University of Texas at Austin, and colleagues examined mortality and factors associated with mortality after a diagnosis of MIS in a population-based cohort study. Data were included for 137,872 patients with a first and only MIS (mean age at diagnosis, 61.9 years); mean follow-up was 6.6 years.

The researchers found that the 15-year melanoma-specific survival was 98.4 percent and the 15-year relative survival was 112.4 percent. Patients with MIS had a melanoma-specific standardized mortality ratio (SMR) of 1.89, while all-cause SMR was 0.68. Older patients had a higher risk for melanoma-specific mortality (7.4 percent for those aged 80 years and older versus 1.4 percent for those aged 60 to 69 years; hazard ratio, 8.2), as did those with acral lentiginous histology results (3.3 percent for acral lentiginous versus 0.9 percent for superficial spreading; hazard ratio, 5.3). Overall, 4.3 percent of those with primary MIS experienced a second primary invasive melanoma and 7.4 percent experienced a second primary MIS. The risk for melanoma-specific mortality was increased for those with a second primary invasive melanoma and was reduced for those with a second primary MIS compared with those without subsequent melanoma (adjusted hazard ratios, 4.1 and 0.7, respectively).

"Patients with a diagnosis of MIS have an increased but low risk of melanoma-specific mortality and live longer than people in the general population, suggesting significant detection of low-risk disease among health-seeking individuals," the authors write.

One author disclosed ties to Concert Genetics.