Unraveling Melanoma's Double Trouble: Exploring Risk Factors for Secondary Lesions

Original Article: Risk Factors Associated With First and Second Primary Melanomas in a High-Incidence Population

What are the key takeaways of this article?

Individuals diagnosed with melanoma have a higher risk of developing subsequent tumors. However, it remains unclear whether this increased risk of developing a second lesion is due to biological factors or behavioral choices. As awareness, detection, and treatment of melanoma have continued to improve, mortality rates have declined. Unfortunately, the incidence of individuals developing a second melanoma lesion is increasing. To better understand and prevent the occurrence of secondary melanoma lesions, the authors of this study aimed to investigate the differences in risk factors between patients with one melanoma versus those with two.

This population-based prospective cohort study included women and men aged 40-69 who were randomly sampled from the general population, with a follow-up period of 7.5 years. Initially, a self-reported survey was conducted to gather demographic and phenotypic data, as well as to assess sun exposure risk. Phenotypic characteristics obtained through self-reporting included hair color, susceptibility to sunburn, ability to tan, density of facial freckles, and density of nevi at age 21. Personal sun exposure questions covered the number of sunburns experienced during different life stages, and cumulative sun exposure based on daily sun exposure hours. Two proxies for high cumulative UV radiation exposure were used in the study: self-reported history of surgically excised non-melanoma skin cancers, and destructively treated actinic skin lesions. Additionally, a polygenic risk score for melanoma was calculated for each participant. The analysis was restricted to individuals of white European ancestry, and participants with a history of invasive or in-situ melanoma were excluded. Genotyping was performed using the Illumina Global Screening array, and participants with unsuccessful arrays were also excluded. In total, 38,845 participants were included in the statistical analysis.

The results of the study indicated that second primary melanomas were more likely to be thin and invasive compared to first primary melanomas. Several associations were found between developing a second primary melanoma as compared to a first, including having a high number of moles at age 21, a high genetic predisposition, and a history of excised skin cancers.

In summary, this large prospective cohort study identified phenotypic risk factors for second primary melanomas, highlighting the differences between individuals with a first primary melanoma and those who developed a secondary one. Individuals with a greater number of nevi at a young age and a higher genetic predisposition should be closely monitored to improve the identification and treatment of secondary primary lesions.

Publication Date: July 28th, 2023

Reference: Olsen CM, Pandeya N, Dusingize JC, et al. Risk Factors Associated With First and Second Primary Melanomas in a High-Incidence Population. JAMA Dermatol. 2023;159(1):37–46. doi:10.1001/jamadermatol.2022.4975

Summary By: McKenzie Van Eaton