Assessment of Trends in Second Primary Cancers in Patients With Metastatic Melanoma From 2005 to 2016

Abstract

Melanoma is one of the most common cancer types and one of the few cancers with increasing incidence in the US.¹ Although treatment options for patients with melanoma, including chemotherapy, surgery, and radiation, have evolved, achieving optimum treatment outcomes continues to be challenging.² This evolution is especially true for metastatic melanoma because it is usually highly resistant to the standard of care.³ The introduction of immune checkpoint inhibitors (ICIs) has substantially improved clinical outcomes in patients with advanced-stage cancers. For example, the 5-year overall survival rate for metastatic melanoma increased from approximately 9% to 18% with ipilimumab.⁴ After the approval of ipilimumab in 2011, other ICIs including nivolumab and pembrolizumab were approved by the US Food and Drug Administration (FDA) for treatment of metastatic melanoma. Because patients with advanced-stage cancers are living longer, long-term treatment and disease-related sequelae are becoming increasingly common on follow-up. One of the most life-threatening sequelae, second primary cancers (SPCs), is often overlooked in the era of immunotherapy.^5,6 However, to our knowledge, the risk of SPCs among patients with metastatic melanoma has not been assessed after ICIs were introduced.