This new research indicates substantial detection of lower-risk disease among patients who are considered to be health-seeking.
Patients with a melanoma in situ (MIS) diagnosis have an increased but still low risk of melanoma-specific death and live longer than those in the general population, new findings suggest, indicating substantial low-risk disease detection among health-seeking patients.1
These findings were explored given that, although there is increasing frequency of MIS diagnosis, very little data exists regarding its link with melanoma-specific or all-cause mortality.2 Knowing the risk for mortality among those with MIS was seen as important for provision of information to identify specific subgroups that may be at higher risk of dying.
Consequently, this research was authored by Adewole S. Adamson, MD, MPP, from the Department of Internal Medicine in Dell Medical School at the University of Texas at Austin.
“In this study, we aimed to evaluate mortality (and factors associated with mortality) after a diagnosis of MIS using several complementary cancer statistics: melanoma-specific survival, relative survival, and SMRs,” Adamson and colleagues wrote.
The investigators conducted a cohort study and examined adults diagnosed with their first primary melanoma in the US from 2000 - 2018. Data from the US Surveillance, Epidemiology, and End Results Program were analyzed by the team to assess mortality outcomes.
The population-based cohort study was completed through the use of the Surveillance, Epidemiology, and End Results (SEER) Program, and the study consisted of 2 cohorts. The first consisted of participants diagnosed with a single primary MIS without any subsequent primary melanomas, aimed to examine the connection between MIS diagnosis and mortality.
The second included all those with a primary MIS, including those who later developed a second primary melanoma. This cohort allowed for the assessment of the risk of developing a second primary melanoma and its overall association with mortality among MIS patients.
The research team evaluated 15-year melanoma-specific survival, 15-year relative survival compared to individuals without melanoma in a similar population, and standardized mortality ratios. They noted the use of Cox regression analysis employed to estimate hazard ratios for death based on clinical and demographic factors. The analysis was conducted between July and September of 2022.
Overall, the study concluded with 137,872 participants, with the average age at diagnosis being 61.9 years. The majority of patients were white (96.7%), with smaller proportions of other ethnic groups.
The average follow-up period by the research team was 6.6 years, and the 15-year melanoma-specific survival rate was shown by the investigators to be 98.4%. The 15-year relative survival rate was shown to be 112.4%.
The research team also concluded that the standardized mortality ratio for melanoma-specific mortality was shown to be 1.89, indicating higher risk. However, the all-cause standardized mortality ratio was 0.68, indicating a lower overall mortality risk compared to the general population.
Acral lentiginous histology and older age were also shown to be linked with a higher risk of melanoma-specific mortality. Among those with primary MIS, 4.3% were noted as having experienced a second primary invasive melanoma, while 7.4% had a second primary MIS.
Those participants with a second primary invasive melanoma ended up with an increased risk of melanoma-specific mortality, whereas those with a second primary MIS ended up with a decreased risk compared to those without subsequent melanomas.
“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,” they wrote.