Researchers have developed a nomogram to help identify patients diagnosed with thin melanomas that are most likely to develop a recurrence. The calculator is available online at www.melanomarisk.org.au.
“Since patients with thin melanomas constitute such a high proportion of all patients diagnosed with melanoma, in absolute numbers, more people ultimately die from T1 melanomas than from T2, T3, or T4 melanomas,” study researchers wrote. “Thus, predicting disease recurrence in patients with T1 melanomas is of great importance.”
The researchers tested the nomogram in a development set consisting of a Dutch cohort of 25,930 patients and validated the risk prediction tool in an Australian cohort of 2968 patients. Multivariable Cox models were generated for local, regional, and distant recurrence-free survival.
The performance of each nomogram was evaluated using calibration plots to define low-risk and high-risk groups as the lowest and highest 5% of the nomogram risk score. Inputs for the nomogram “are readily available and can be obtained from the primary melanoma itself.”
In the development model, C-statistics of 0.79, 0.77, and 0.80 were found for local recurrence-free survival, regional recurrence-free survival, and distant recurrence-free survival, respectively. In the validation model, these C-statistics were 0.80, 0.76, and 0.74, respectively.
The current staging system considers only T-stage and sentinel node status to predict survival in T1 melanoma, the researchers noted.
“We found that the predictive performance for [local recurrence-free survival, regional recurrence-free survival, and distant recurrence-free survival](indicated by the C-statistic) increased from 0.67, 0.68, and 0.70, respectively, for the model including T-stage and SN status to 0.79, 0.77, and 0.80, respectively, by using the current nomogram for the development cohort, and from 0.65, 0.66, and 0.65, respectively, to 0.80, 0.76, and 0.74, respectively, for the validation cohort,” they wrote.
This newly developed nomogram will “assist in the planning of appropriate follow-up schedules and determining clinical trial eligibility and stratification.”
El Sharouni M-A, Ahmed T, Varey AHR, et al. Development and validation of nomograms to predict local, regional, and distant recurrence in patients with thin (T1) melanomas. J Clin Oncol. Published online February 18, 2021.doi:10.1200/JCO.20.02446