Merkel Cell Less Common, With Higher Mortality Than Melanoma

TOPLINE:

Merkel cell carcinoma (MCC) is less common and is associated with higher mortality rates than melanoma, according to a study that also reported that male gender, older age, and exposure to ultraviolet radiation (UVR) are significant risk factors.

METHODOLOGY:

• Researchers identified 19,444 MCC cases and 646,619 melanoma cases diagnosed between 2000 and 2021 using data from the Surveillance, Epidemiology, and End Results (SEER) Program.
• Ambient UVR exposure data were obtained from the National Aeronautics and Space Administration’s total ozone mapping spectrometer database.
• Risk factors and cancer-specific mortality rates were evaluated for both cancers.

TAKEAWAY:

• Incidence rates per 100,000 person-years of MCC and melanoma were 0.8 and 27.3, respectively.
• Men (adjusted incidence rate ratio [IRR], 1.72 for MCC and 1.23 for melanoma), older age groups (IRR: 2.69 for MCC and 1.62 for melanoma among those 70-79 years; and 5.68 for MCC and 2.26 for melanoma among those 80 years or older) showed higher incidences of MCC and melanoma. Non-Hispanic White individuals were at higher risk for MCC and melanoma than other racial/ethnic groups.
• Exposure to UVR was associated with higher incidences of melanoma (IRR, 1.24-1.49) and MCC (IRR, 1.15-1.20) in non-Hispanic White individuals, particularly on the head and neck. These associations were unclear among racial/ethnic groups.
• Individuals with MCC had a higher risk for cancer-specific mortality than those with melanoma (adjusted hazard ratio [HR], 2.33; 95% CI, 2.26-2.42). Cancer-specific survival for both cancers improved for cases diagnosed during 2012-2021 vs 2004-2011 (MCC: HR, 0.83; 95% CI, 0.78-0.89; melanoma: HR, 0.75; 95% CI, 0.74-0.76).

IN PRACTICE:

“MCC and melanoma are aggressive skin cancers with similar risk factors including male sex, older age, and UV radiation exposure. Clinicians should be alert to diagnosis of these cancers to allow for prompt treatment,” the authors wrote, adding: “It is encouraging that survival for both cancers has increased in recent years, with the largest gains in survival seen in distant stage melanoma, coinciding with the approval of BRAF and PD-1 inhibitors used for distant stage disease,” although mortality for advanced stage tumors “continues to be very high.”

SOURCE:

The study was led by Jacob T. Tribble, BA, National Cancer Institute, Rockville, Maryland. It was published online on January 5 in the Journal of Investigative Dermatology.

LIMITATIONS:

The study relied on SEER’s general staging system rather than the American Joint Committee on Cancer standard, and UVR exposure estimates did not account for individual sun protection behaviors or prior residential history. Race and ethnicity served as a proxy for UVR sensitivity, which may introduce misclassification bias.

DISCLOSURES:

The research was supported by the Intramural Research Program of the National Cancer Institute, the National Institutes of Health, the American Association for Dental Research, and the Colgate-Palmolive Company. The authors reported no conflict of interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.