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

Association of Inherited Genetic Variants with Multiple Primary Melanoma

BACKGROUND

Recent genome-wide association studies (GWAS) have identified new susceptibility loci for melanoma, but their associations with multiple primary melanoma (MPM) are unclear.

METHODS

We investigated the associations of 69 SNPs in 39 GWAS-identified loci with odds of MPM relative to single primary melanoma in the international, population-based Genes, Environment, and Melanoma study. Per-minor-allele ORs and 95% confidence intervals (CI) for individuals with MPM "cases" (n = 1,205) relative to single primary melanoma "controls" (n = 2,458) were estimated using multivariable logistic regression, and polygenic risk scores (PRS) were calculated and weighted based on a 2020 GWAS meta-analysis (57 of the 68 independent GWAS SNPs available).

RESULTS

Thirteen SNPs in 11 gene regions (PARP1, CYP1B1/RMDN3, TERT, RAPGEF5, TYRP1, MTAP, CDKN2A/CDKN2B, KLF4, TYR, SOX6, and ASIP) were statistically significantly associated (P < 0.05) with MPM adjusting for age, sex, age-by-sex interaction, and study center. The highest versus lowest PRS quintile was associated with a 2.81-fold higher odds of MPM (95% CI, 2.10-3.78; P = 7.5 × 10-13); this association was attenuated but remained statistically significant after excluding SNPs individually associated with MPM (OR = 1.75, 95% CI, 1.32-2.31).

CONCLUSIONS

Inherited genetic variants spanning 11 gene regions were independently associated with MPM. Nonsignificant SNPs were associated with MPM when aggregated into a PRS, indicating that their cumulative effect may influence MPM risk despite lacking individual statistical significance in our study population.

IMPACT

Our findings provide additional evidence that these loci are associated with melanoma risk and estimate the magnitude of their genetic effect on subsequent (multiple) primary melanoma risk.

Evaluating an approach for communicating integrated risk scores for melanoma

Integrated risk scores (polygenic and non-genetic risk factors) can facilitate risk-stratification, to inform targeted melanoma screening. This mixed-methods pilot study assessed satisfaction, attitudes, and psychosocial impact of a protocol for communicating integrated risk for melanoma using questionnaires (baseline and 1-month post-results) and semi-structured interviews. Affected and unaffected adults enroled in ongoing melanoma studies were recruited to receive their integrated risk booklets and attend a genetic counselling appointment. 35/73 consented to participate; 31 and 33 completed baseline and follow-up questionnaires, respectively. Participants rated the information as useful, felt it motivated favourable health behaviours and were satisfied with the quality and content of the booklet. All participants felt highly empowered managing melanoma risk at baseline and follow-up. Most participants were unsure or felt little to no control over preventing future melanomas, which did not change at follow-up (Chi-square p = 0.73). Genetic-specific distress, and uncertainty was low for all participants post-results. Qualitative interviews supported quantitative findings and highlighted importance of access to a clinician for results interpretation and risk-management. In this high-risk cohort, the communication model was acceptable, and did not result in negative psychosocial sequelae. Findings from this study highlight key considerations for effective communication and delivery of integrated risk which can be used to inform future research in more diverse cohorts for melanoma and other common conditions.

Triple Primary Cancers: An Analysis of Genetic and Environmental Factors

The occurrence of multiple primary cancers (MPC) is thought to reflect increased cancer susceptibility in patients due to a combination of genetic and environmental factors. Here we conducted a retrospective review of 2,894 consecutive patients evaluated at a single institution and identified 31 (1.14%) individuals with a history of three or more primary cancers, then analyzed the genetic and environmental influences associated with their propensity for developing malignancies. We found that 35.5% of patients had a hereditary cancer syndrome (HCS), with high penetrance HCS in 72.7% of cases, suggesting that monogenic causes underly a significant proportion of triple primary cancer risk. Analysis of cancer frequencies found that the diagnosis of breast cancer was associated with a significantly lower likelihood of HCS, while the diagnosis of colorectal, prostate, and pancreas cancer was associated with a significantly higher likelihood of HCS. Comparison of HCS-positive and HCS-negative patients revealed similar demographic characteristics, mean age at first diagnosis, and family history of cancer. Moreover, no significant differences in lifestyle behaviors, occupational exposures, chronic health conditions, or treatment with chemotherapy and radiation were observed between HCS-positive and -negative groups, though outliers in tobacco smoking, as well as systemic treatment after both first and second primary cancers were observed. These findings indicate a robust contribution of HCS to cancer susceptibility among patients with triple primary cancers while environmental influences were less evident. This emphasizes the need for larger MPC cohorts incorporating additional genetic and environmental factors to more comprehensively characterize drivers of cancer risk.

PREVENTION RELEVANCE

In patients with three or more primary cancers, genetic predisposition explained a significant proportion of cases; however, treatment history, lifestyle habits, and other exposures appeared to play a less significant role. This highlights the value of early genetic screening and the need to develop more sensitive markers of cancer susceptibility. See related Spotlight, p. 193.

Incidence and Factors Associated With Second Primary Invasive Melanoma in Norway

Importance

Patients diagnosed with a primary melanoma are at high risk of subsequent melanomas. Understanding the risk of second primary invasive melanoma and associated factors is crucial to optimize patient follow-up.

Objective

To assess the incidence rate of second primary invasive melanoma and time between the first and second primary invasive melanoma in the Norwegian population.

Design, Setting, and Participants

This population-based cohort study included data from deidentified records of all invasive melanomas diagnosed in Norway in 2008 to 2020, obtained from the Cancer Registry of Norway. Data were from adults aged 18 years or older diagnosed with a first primary melanoma. Data analysis was performed from March to August 2023.

Main Outcomes and Measures

The main outcome was the incidence rate of second primary invasive melanoma at least 30 days after the first. Accelerated failure time models were fitted to examine potential associations with patient and tumor characteristics. Median time between first and second primary melanomas and 95% CIs were calculated. The likelihood of, and median interval for, second primary melanomas on the same or different site as the first primary were calculated.

Results

A total of 19 196 individuals aged 18 years or older were diagnosed with a first primary melanoma. The mean (SD) age at diagnosis of the first primary melanoma was 62 (16) years (range, 18-104 years), and 9763 (51%) were female. The incidence rate in the year following diagnosis was 16.8 (95% CI, 14.9-18.7) per 1000 person-years, which decreased to 7.3 (95% CI, 6.0-8.6) during the second year and stabilized thereafter. Median time between first and second primaries decreased with advancing age and was 37 months (95% CI, 8-49) in patients younger than 40 years, 18 (95% CI, 13-24) in patients aged 50 to 59 years, and 11 (95% CI, 7-18) in patients aged 80 years or older. The second primary was on the same site as their first primary for 47% (359 patients), and on a different site for 53% (407 patients). The median interval until second melanoma on the same site as the initial melanoma was 12 (95% CI, 7-19) months in men and 22 (95% CI, 11-35) months in women.

Conclusions and Relevance

Older age and male sex were associated with an increased risk, suggesting that increased surveillance intensity may be considered for men, especially those older than 50 years, for at least 3 years after their initial diagnosis, regardless of the characteristics of their first invasive melanoma.

Risk factors for subsequent primary melanoma in patients with previous melanoma: a systematic review and meta-analysis

BACKGROUND

Compared with the general population, people with a previous melanoma are at increased risk of developing another primary melanoma. Understanding the risk factors associated with multiple primary melanomas can inform patient education and tailored surveillance.

OBJECTIVES

To examine the risk factors for subsequent primary melanoma in people with a previous melanoma, by conducting a systematic review and meta-analysis of the available data.

METHODS

A systematic literature search was conducted in CINAHL, Cochrane Central Register of Controlled Trials (CENTRAL), Embase and MEDLINE. Studies that reported a risk estimate or raw frequencies and conducted between 1982 and August 2022 were included. Adjusted risk estimates were prioritized over univariable risk estimates. PRISMA reporting guidelines were followed. Random effects meta-analysis was conducted to derive pooled estimates. Quality assessment was conducted by two researchers using the Newcastle-Ottawa scale. GRADE was used to rate the certainty and quality of the evidence.

RESULTS

Data from 27 studies involving 413 181 participants were pooled and analysed. Risk factors assessed included age and sex, environmental, lifestyle, phenotypic, genetic and histopathological factors, and there was wide variation in how they were categorized and analysed. Independent risk factors identified from pooled analyses included male sex [hazard ratio (HR) 1.46, 95% confidence interval (CI) 1.40-1.53], increasing age per 10 years (HR 1.19, 95% CI 1.14-1.24), light skin colour (HR 1.44, 95% CI 1.23-1.70), family history [odds ratio (OR) 1.79, 95% CI 1.25-2.56], CDKN2A mutation (OR 5.29, 95% CI 2.70-10.37), a high or moderate naevus count [OR 2.63 (95% CI 1.61-4.30) and OR 1.64 (95% CI 1.07-2.51), respectively], one or more atypical naevi (OR 3.01, 95% CI 1.52-5.97), first lesions occurring on the head or neck, lentigo maligna subtype (HR 1.16, 95% CI 1.15-1.17), other subtype (HR 1.14, 95% CI 1.03-1.27) and inadequate sun protection (HR 1.85, 95% CI 0.98-3.50). Based on the GRADE criteria, there was high to very low confidence in the pooled effect estimates.

CONCLUSIONS

This meta-analysis identified several consistent, independent risk factors for the development of subsequent primary melanoma. These findings will help stratify the risk of subsequent melanoma, tailor skin-check schedules and inform patient education.