• Comparative performance of predictors of death from thin (≤1.0 mm) melanoma

      Claeson, M.; Baade, P.; Marchetti, M.; Brown, S.; Soyer, H. P.; Smithers, B. M.; Green, Adèle C; Whiteman, D. C; Khosrotehrani, K.; Department of Population Health, QIMR Berghofer Medical Research Institute, Brisbane, Australia. (2021)
      Despite overall favourable prognosis,1 thin (≤1.0 mm) cutaneous melanoma account for 23% of melanoma deaths in the high-risk general population of Queensland, Australia (2005-2009), because of the sheer volume of disease.2 The prospect of adjuvant systemic therapy has increased the focus on identifying patients with thin melanoma who are at high risk of death, such as through gene expression profiling (GEP), sentinel lymph node biopsy (SLNB), or prognostic models.3-5.
    • Destructive and topical treatments of skin lesions in organ transplant recipients and relation to skin cancer

      Green, Adèle C; Way, M.; Oster, M.; Plasmeijer, E. I.; Jiyad, Z.; O'Rourke, P.; Miura, K.; Campbell, S.; Isbel, N.; Chambers, D. C.; et al. (2020)
      Various treatments of keratotic skin lesions and early skin cancers are performed in organ transplant recipients (OTRs) at high risk of skin malignancies but the frequency of their use is unknown. We prospectively assessed the frequency of use of cryotherapy, diathermy, and topical therapies and also investigated their associations with background incidence of histologically-confirmed squamous-cell carcinoma (SCC) and basal cell carcinoma (BCC) in a cohort of OTRs in Queensland, Australia. Median follow-up ranged from 1.7 to 3.2 years across organ transplant groups. Among 285 kidney, 125 lung and 203 liver transplant recipients [382 (62%) male, 380 (62%) immunosuppressed > 5 years, 394 (64%) previously diagnosed with skin cancer], 306 (50%) reported treatment of skin lesions with major types of non-excision therapies during follow-up: 278 (45%) cryotherapy or diathermy; 121 (20%) topical treatments. Of these 306, 150 (49%) developed SCC at double the incidence of those who did not receive these treatments, as assessed by incidence rate ratio (IRR) adjusted for age, sex, type of organ transplant, skin color and history of skin cancer at baseline, calculated by multivariable Poisson regression (IRRadj = 2.1, 95% confidence interval (CI) 1.4-3.1). BCC incidence was not associated with these therapies. Skin lesions in OTRs that are treated with cryotherapy, diathermy, or topical treatment warrant judicious selection and careful follow-up.
    • Genome-wide association meta-analyses combining multiple risk phenotypes provide insights into the genetic architecture of cutaneous melanoma susceptibility

      Landi, MT; Bishop, D T; MacGregor, S; Machiela, MJ; Stratigos, AJ; Ghiorzo, P; Brossard, M; Calista, D; Choi, J.; Fargnoli, MC; et al. (2020)
      Most genetic susceptibility to cutaneous melanoma remains to be discovered. Meta-analysis genome-wide association study (GWAS) of 36,760 cases of melanoma (67% newly genotyped) and 375,188 controls identified 54 significant (P < 5 x 10(-8)) loci with 68 independent single nucleotide polymorphisms. Analysis of risk estimates across geographical regions and host factors suggests the acral melanoma subtype is uniquely unrelated to pigmentation. Combining this meta-analysis with GWAS of nevus count and hair color, and transcriptome association approaches, uncovered 31 potential secondary loci for a total of 85 cutaneous melanoma susceptibility loci. These findings provide insights into cutaneous melanoma genetic architecture, reinforcing the importance of nevogenesis, pigmentation and telomere maintenance, together with identifying potential new pathways for cutaneous melanoma pathogenesis.
    • Omega-3 fatty acid intake and decreased risk of skin cancer in organ transplant recipients

      Miura, K.; Way, M.; Jiyad, Z.; Marquart, L.; Plasmeijer, E. I.; Campbell, S.; Isbel, N.; Fawcett, J.; Ferguson, L. E.; Davis, M.; et al. (2020)
      Purpose: Organ transplant recipients have over 100-fold higher risk of developing skin cancer than the general population and are in need of further preventive strategies. We assessed the possible preventive effects of omega-3 polyunsaturated fatty acid (PUFA) intake from food on the two main skin cancers, squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) in kidney and liver transplant recipients. Methods: Adult kidney or liver transplant recipients transplanted for at least 1 year and at high risk of skin cancer were recruited from the main transplant hospital in Queensland, 2012-2014 and followed until mid-2016. We estimated their dietary total long-chain omega-3 PUFAs and α-linolenic acid intakes at baseline using a food frequency questionnaire and ranked PUFA intakes as low, medium, or high. Relative risks (RRsadj) of skin cancer adjusted for confounding factors with 95% confidence intervals (CIs) were calculated. Results: There were 449 transplant recipients (mean age, 55 years; 286 (64%) male). During follow-up, 149 (33%) patients developed SCC (median 2/person; range 1-40) and 134 (30%), BCC. Transplant recipients with high total long-chain omega-3 PUFA compared with low intakes showed substantially reduced SCC tumour risk (RRadj 0.33, 95% CI 0.18-0.60), and those with high α-linolenic acid intakes experienced significantly fewer BCCs (RRadj 0.40, 95% CI 0.22-0.74). No other significant associations were seen. Conclusion: Among organ transplant recipients, relatively high intakes of long-chain omega-3 PUFAs and of α-linolenic acid may reduce risks of SCC and BCC, respectively.
    • Polygenic risk scores stratify keratinocyte cancer risk among solid organ transplant recipients with chronic immunosuppression in a high ultraviolet radiation environment.

      Seviiri, M.; Law, M. H.; Ong, J. S.; Gharahkhani, P.; Nyholt, D. R.; Hopkins, P.; Chambers, D.; Campbell, S.; Isbel, N. M.; Soyer, H. P.; et al. (2021)
      Solid organ transplant recipients (SOTRs) have elevated risks for basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), especially in high UVR environments. We assessed whether polygenic risk scores can improve the prediction of BCC and SCC risks and multiplicity over and above the traditional risk factors in SOTRs in a high UV setting. We built polygenic risk scores for BCC (n = 594,881) and SCC (n = 581,431) using UK Biobank and 23andMe datasets, validated them in the Australian QSkin Sun and Health Study cohort (n > 6,300), and applied them in SOTRs in the skin tumor in allograft recipients cohort from Queensland, Australia, a high UV environment. About half of the SOTRs with a high genetic risk developed BCC (absolute risk = 45.45%, 95% confidence interval = 33.14-58.19%) and SCC (absolute risk = 44.12%, 95% confidence interval = 32.08-56.68%). For both cancers, SOTRs in the top quintile were at >3-fold increased risk relative to those in the bottom quintile. The respective polygenic risk scores improved risk predictions by 2% for BCC (area under the curve = 0.77 vs. 0.75, P = 0.0691) and SCC (area under the curve = 0.84 vs. 0.82, P = 0.0260), over and above the established risk factors, and 19.03% (for BCC) and 18.10% (for SCC) of the SOTRs were reclassified in a high/medium/low risk scenario. The polygenic risk scores also added predictive accuracy for tumor multiplicity (BCC R2 = 0.21 vs. 0.19, P = 3.2 × 10-3; SCC R2 = 0.30 vs. 0.27, P = 4.6 × 10-4).
    • Polygenic risk scores stratify keratinocyte cancer risk among solid organ transplant recipients with chronic immunosuppression in a high ultraviolet radiation environment.

      Seviiri, M.; Law, M. H.; Ong, J. S.; Gharahkhani, P.; Nyholt, D. R.; Hopkins, P.; Chambers, D.; Campbell, S.; Isbel, N. M.; Soyer, H. P.; et al. (2021)
      Solid organ transplant recipients (SOTRs) have elevated risks for basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), especially in high UVR environments. We assessed whether polygenic risk scores can improve the prediction of BCC and SCC risks and multiplicity over and above the traditional risk factors in SOTRs in a high UV setting. We built polygenic risk scores for BCC (n = 594,881) and SCC (n = 581,431) using UK Biobank and 23andMe datasets, validated them in the Australian QSkin Sun and Health Study cohort (n > 6,300), and applied them in SOTRs in the skin tumor in allograft recipients cohort from Queensland, Australia, a high UV environment. About half of the SOTRs with a high genetic risk developed BCC (absolute risk = 45.45%, 95% confidence interval = 33.14-58.19%) and SCC (absolute risk = 44.12%, 95% confidence interval = 32.08-56.68%). For both cancers, SOTRs in the top quintile were at >3-fold increased risk relative to those in the bottom quintile. The respective polygenic risk scores improved risk predictions by 2% for BCC (area under the curve = 0.77 vs. 0.75, P = 0.0691) and SCC (area under the curve = 0.84 vs. 0.82, P = 0.0260), over and above the established risk factors, and 19.03% (for BCC) and 18.10% (for SCC) of the SOTRs were reclassified in a high/medium/low risk scenario. The polygenic risk scores also added predictive accuracy for tumor multiplicity (BCC R2 = 0.21 vs. 0.19, P = 3.2 × 10-3; SCC R2 = 0.30 vs. 0.27, P = 4.6 × 10-4).
    • Reproducible naevus counts using 3D total body photography and convolutional neural networks

      Betz-Stablein, B.; D'Alessandro, B.; Koh, U.; Plasmeijer, E.; Janda, M.; Menzies, S. W.; Hofmann-Wellenhof, R.; Green, Adèle C; Soyer, H. P.; QIMR Berghofer Medical Research Institute, Cancer and Population Studies, Brisbane, Queensland, Australia. (2021)
      Background: The number of naevi on a person is the strongest risk factor for melanoma; however, naevus counting is highly variable due to lack of consistent methodology and lack of inter-rater agreement. Machine learning has been shown to be a valuable tool for image classification in dermatology. Objectives: To test whether automated, reproducible naevus counts are possible through the combination of convolutional neural networks (CNN) and three-dimensional (3D) total body imaging. Methods: Total body images from a study of naevi in the general population were used for the training (82 subjects, 57,742 lesions) and testing (10 subjects; 4,868 lesions) datasets for the development of a CNN. Lesions were labelled as naevi, or not ("non-naevi"), by a senior dermatologist as the gold standard. Performance of the CNN was assessed using sensitivity, specificity, and Cohen's kappa, and evaluated at the lesion level and person level. Results: Lesion-level analysis comparing the automated counts to the gold standard showed a sensitivity and specificity of 79% (76-83%) and 91% (90-92%), respectively, for lesions ≥2 mm, and 84% (75-91%) and 91% (88-94%) for lesions ≥5 mm. Cohen's kappa was 0.56 (0.53-0.59) indicating moderate agreement for naevi ≥2 mm, and substantial agreement (0.72, 0.63-0.80) for naevi ≥5 mm. For the 10 individuals in the test set, person-level agreement was assessed as categories with 70% agreement between the automated and gold standard counts. Agreement was lower in subjects with numerous seborrhoeic keratoses. Conclusion: Automated naevus counts with reasonable agreement to those of an expert clinician are possible through the combination of 3D total body photography and CNNs. Such an algorithm may provide a faster, reproducible method over the traditional in person total body naevus counts.