IN RECENT years, there has been extensive research into the role of tumour mutational burden (TMB) in cutaneous melanoma, particularly as a key prognostic factor for immune checkpoint inhibitor therapies. TMB is closely linked to increased mutagenesis from UV exposure, contributing to better clinical outcomes. However, the specific relationship between TMB and indoor tanning remains uncertain.
This cohort study aimed to explore the association between TMB in cutaneous melanoma and indoor tanning exposure, as well as other clinical characteristics. Conducted at Dana-Farber Cancer Institute in Boston, the study included 617 melanoma patients with available next-generation sequencing data and indoor tanning histories. The findings revealed no significant association between indoor tanning exposure and TMB. After adjusting for demographic, tumour, and dermatologic factors, TMB levels remained consistent regardless of indoor tanning history. However, higher TMB was associated with older age at diagnosis, a history of nonmelanoma skin cancer, and tumours located in sun-exposed areas such as the head and neck. Conversely, patients with a history of atypical nevi exhibited significantly lower TMB levels.
These results suggest that while indoor tanning is a well-established risk factor for melanoma, it does not appear to contribute to TMB in cutaneous melanoma tumours. Instead, other clinical factors such as age, sun-exposed tumour sites, and history of nonmelanoma skin cancer are more strongly linked to elevated TMB, which may impact immune checkpoint inhibitor therapy responses.
Understanding these relationships is critical for optimising melanoma treatment strategies, particularly when considering immune checkpoint inhibitors. Further research into these associations could enhance melanoma management, especially in patients with elevated TMB, ensuring that treatment approaches are tailored based on tumour characteristics rather than solely on patient history of indoor tanning exposure.
Katie Wright, EMJ
Reference
Hanrahan GB et al. Melanoma tumor mutational burden and indoor tanning exposure. JAMA Dermatol. 2024;DOI:10.1001/jamadermatol.2024.4819.
