A risk prediction model for the development of subsequent primary melanoma
July 3, 2020
Abstract
Background: Guidelines for follow‐up of patients with melanoma are based on limited evidence.
Objectives: To guide skin surveillance, we developed a risk prediction model for subsequent primary melanomas, using demographic, phenotypical, histopathological, sun exposure and genomic risk factors.
Methods: Using Cox regression frailty models, we analysed data for 2613 primary melanomas from 1266 patients recruited to the population‐based Genes, Environment and Melanoma study in New South Wales, Australia, with a median of 14 years’ follow‐up via the cancer registry. Discrimination and calibration were assessed.
Results: The median time to diagnosis of a subsequent primary melanoma decreased with each new primary melanoma. The final model included 12 risk factors. Harrell's C‐statistic was 0·73 [95% confidence interval (CI ) 0·68–0·77], 0·65 (95% CI 0·62–0·68) and 0·65 (95% CI 0·61–0·69) for predicting second, third and fourth primary melanomas, respectively. The risk of a subsequent primary melanoma was 4·75 times higher (95% CI 3·87–5·82) for the highest vs. the lowest quintile of the risk score. The mean absolute risk of a subsequent primary melanoma within 5 years was 8·0 ± SD 4.1% after the first primary melanoma, and 46·8 ± 15·0% after the second, but varied substantially by risk score.
Conclusions: The risk of developing a subsequent primary melanoma varies considerably between individuals and is particularly high for those with two or more primary melanomas. The risk prediction model and its associated nomograms enable estimation of the absolute risk of subsequent primary melanoma, on the basis of on an individual's risk factors, and can be used to tailor surveillance intensity, communicate risk and provide patient education.
Source:
Cust, A., Badcock, C., Smith, J., Thomas, N., Haydu, L., Armstrong, B., Law, M., Thompson, J., Kanetsky, P., Begg, C., Shi, Y., Kricker, A., Orlow, I., Sharma, A., Yoo, S., Leong, S., Berwick, M., Ollila, D. and Lo, S. (2020), A risk prediction model for the development of subsequent primary melanoma in a population‐based cohort. Br J Dermatol, 182: 1148-1157. doi:10.1111/bjd.18524