Prediction in cutaneous melanomas: A multicontinental approach

This thesis is a collaboration between the University Medical Center Utrecht and Melanoma Institute Australia, Sydney, Australia. One in 5 Dutch people will get diagnosed with skin cancer in their life. In 10% of cases this concerns a melanoma. Although melanoma is not the most common form of skin cancer, it is responsible for 70-90% of skin-cancer related deaths. Melanoma cells can spread through the lymphatic system. The sentinel node is the first lymph node that melanoma cells spread to. On average, 1 in 5 sentinel node biopsies contains metastatic melanoma cells. This thesis investigates how often the sentinel node procedure has been enacted in the Netherlands in the last years, the chance of metastatic cells in the sentinel node, and the additional prognostic value of sentinel node status over basic clinicopathological features of a melanoma. In addition, the concordance of sentinel node biopsies that were initially diagnosed positive for melanoma metastases has been reviewed, as well as the effect of time interval between melanoma diagnosis and sentinel node biopsy on survival and on the size of metastatic tumour deposits. The impact of several clinicopathological characteristics on survival are evaluated in this thesis, e.g. sex, melanoma subtype and the presence of multiple primary melanomas. Finally, two prediction models are developed: one to predict recurrence of disease in patients with thin melanomas, and one to accurately predict the chance of metastatic cells in the sentinel node.