Risk of second primary cutaneous and noncutaneous melanoma after cutaneous melanoma diagnosis: A population-based...

While cutaneous melanomas (CM) account for greater than 90% of all melanomas, noncutaneous melanomas (NCM) are more aggressive and associated with worse outcomes. The shared progenitor cell type among CM and NCM suggests that patients with a history of CM may be at higher risk for subsequent NCM.

To determine whether patients with a history of CM demonstrate an increased risk of second primary cutaneous, ocular, oral, or vaginal/exocervical melanoma compared with the general population.

This was a population-based retrospective cohort study using the Surveillance, Epidemiology, and End Results database. We calculated standardized incidence ratios (SIRs) and excess absolute risks of second primary cutaneous, ocular, oral, and vaginal/exocervical melanoma in patients with a history of CM.

Patients with prior CM (n = 169,841) were more likely than the general population to develop a second primary CM (SIR, 8.17; 95% confidence interval [CI], 8.01-8.33), ocular melanoma (SIR, 1.99; 95% CI, 1.54-2.53), oral melanoma (SIR, 6.87; 95% CI, 2.23-16.04), and vaginal/exocervical melanoma (SIR, 10.17; 95% CI, 4.65-19.30).

This study is limited by possible under-reporting of CM in cancer registries.

In caring for patients with a history of CM, physicians should be vigilant not only about risk of recurrence but also about second primary CM and NCM.