Microsatellites may be associated with poorer survival outcomes in melanoma

The presence of microsatellites was associated with poorer overall survival in a retrospective cohort of patients with cutaneous melanoma, according to a study.

“There is limited information on microsatellite survival outcomes in melanoma patients,” Constanza Riquelme Mc Loughlin, PhD, MD, of the dermatology department at the Hospital Clinic of Barcelona at the University of Barcelona, Spain, and colleagues wrote.

In the current retrospective analysis, Riquelme Mc Loughlin and colleagues determined survival outcomes in patients with microsatellites and assessed the role of those microsatellites in stage III stratification of American Joint Committee on Cancer (AJCC) classification. They also evaluated results of sentinel lymph node biopsies in patients with microsatellites, according to the findings.

The analysis included 5,216 patients diagnosed with cutaneous melanoma between 1998 and 2019.

Overall, 2.1% (n = 108) of the cohort had microsatellites at initial staging.

Multivariate analysis results showed that microsatellites were associated with poorer overall survival (HR = 1.57; 95% CI, 1.22-2.01). In addition, melanoma specific survival (HR = 1.76; 95% CI, 1.32-2.34) and disease-free survival (HR = 1.76; 95% CI, 1.36-2.27) also were reduced among patients with microsatellites.

Stratified analysis for stage III patients demonstrated that the 5-year overall survival in patients with stage IIIB disease who also had microsatellites was 35% (95% CI, 17.3%-73.4%). Melanoma-specific survival was 45% (95% CI, 23.1%-87.5%) in this same patient group.

In the univariate analysis, factors associated with the three survival outcomes included being aged older than 42 years at diagnosis, male sex, more advanced AJCC T stage, tumor ulceration, presence of microsatellites and distal metastasis, according to the findings.

The applicability of the findings may be limited by the retrospective nature of the study.

“Previous studies in melanoma patients with microsatellites found a relatively poor survival prognosis associated with this group of patients,” the researchers concluded.

Based on their study, Riquelme Mc Loughlin and colleagues further wrote that sentinel lymph node biopsy should be recommended for patients with microsatellites in the primary tumor.