Comparison of Survival Between Patients With Single vs Multiple Primary Cutaneous Melanomas

Abstract

IMPORTANCE Melanoma is one of the most rapidly increasing forms of cancer worldwide. Most studies about survival among patients with melanoma consider only the primary tumor and disregard the potential effect of multiple primary tumors. A better understanding of the prognosis of patients with multiple primary melanoma is important for patient counselling and follow-up strategies. OBJECTIVE To describe the epidemiologic features of multiple primary melanoma in patients from the Netherlands. DESIGN, SETTING, AND PARTICIPANTS This retrospective, population-based cohort study included adults with histologically proven, primary, invasive cutaneous melanoma in the Netherlands between January 1, 2000, and December 31, 2014, with a median follow-up of 75.1 months, using data from PALGA, the Dutch Nationwide Network and Registry of Histopathology and Cytopathology. Follow-up data were retrieved from the Netherlands Cancer Registry. Statistical analysis was performed from August 1, 2018, to September 3, 2018. MAIN OUTCOMES AND MEASURES A multivariable Cox model with a time-varying covariate was performed to assess overall survival between patients with a single primary melanoma vs those with multiple primary melanomas. Secondary outcomes included incidence of multiple primary melanoma, differences in Breslow thickness, and time between first and second multiple primary melanoma. RESULTS Of the 56 929 study patients, 31 916 (56.1%) were female, with a mean (SD) age of 56.4 (16.2) years. A total of 54 645 single primary melanomas and 4967 multiple primary melanomas in 2284 patients were included. The median Breslow thickness decreased from 0.90 mm (interquartile range, 0.55-1.70 mm) for the first melanoma to 0.65 mm (interquartile range, 0.45-1.10 mm) for the second melanoma (P < .001). For their second melanoma, 370 patients (16.2%) had a higher T stage, 1112 (48.7%) had the same T stage, and 802 (35.1%) had a lower T stage. In addition, 841 of 2284 second melanomas (36.8%) in patients with multiple primary melanomas were found during the first year of follow-up, whereas 624 of 2284 (27.3%) were found after 5 years of follow-up. These proportions did not vary when stratified for melanoma stage. Worse overall survival was seen among patients with multiple primary melanomas compared with patients with a single primary melanoma (hazard ratio, 1.31; 95% CI, 1.20-1.42; P < .001). CONCLUSIONS AND RELEVANCE A significant decrease in Breslow thickness between the first and second multiple primary melanoma was found, and overall survival among patients with multiple primary melanomas was significantly worse than that among patients with a single primary melanoma. These findings suggest that more strict follow-up strategies may be warranted for patients with multiple primary melanomas.

Subtyping Cutaneous Melanoma Matters

“…Patients with noncutaneous melanoma, desmoplastic melanoma, melanoma of unknown primary, and patients without a defined melanoma subtype were excluded. We also excluded patients with multiple primary melanoma, because we previously showed that these patients have worse prognosis ( 15 ). Melanoma occurring in children (age <18 years) were excluded as well.…”

Survival in patients with multiple primary melanomas: Systematic review and meta-analysis

“…Studies were classified based on the method used to calculate the survival interval (supplemental Fig 1). Four studies addressed the issue of survival bias using a delayed entry or a variable entry method and were included in the meta-analysis [19][20][21][22] .…”

“…The delayed entry or the varying time entry methods minimize bias by allowing for consideration of total time between first and subsequent events [17] . Although these methods have been established in other settings of repeated time-dependent events [18] they have not been used for MPM survival until recently [19][20][21][22].…”

Unraveling the Role of microRNA and isomiRNA Networks in Multiple Primary Melanoma Pathogenesis

“…Despite the increased risk of multiple tumor development, there is still an open debate about the prognosis of MPM patients. On one hand, Doubrovsky et al observer a favorable prognosis in patients with MPM 16 , but a worse prognosis for these patients was recently reported by El Sharouni and colleagues 17 .…”