The incidence of cutaneous melanoma, especially thin (≤ 1.0 mm) melanomas, continues to increase worldwide. Breslow thickness, ulceration and sentinel lymph node status, which are currently regarded as the most accurate prognostic markers, fail to identify patients at high risk of disseminating disease amongst those with thin melanomas.
Autoantibodies reflect a biologically amplified, stable signature of the anti-tumour immune response that is produced often prior to the clinical detection of other tumour markers and prior to the first clinically detectable signs of cancer recurrence.
In this retrospective study, clinical data was extracted from the population- based Western Australia Cancer Registry, regarding the survival outcomes of 104 early stage (in situ -stage II) melanoma patients. Sera (n=104) were screened against a high-throughput microarray platform containing 1627 functional proteins. Patients were excluded from further analysis if patient has developed melanoma recurrence (n=12), was diagnosed with a new primary melanoma (n=7) or in case of no follow-up data being available (n=4). Out of 81 patients 10 patients progressed. The potential of autoantibodies to predict the risk for progression was evaluated by analysing the autoantibody profiles exhibited on the microarray at the time of diagnosis relative to their present disease status. The ultimate selection of two potentially prognostic autoantibodies was based on the calculation of their biomarker score, which represents the frequency and strength of the signal in patients who progressed compared to the ones who did not progress. The top 10% of the autoantibodies exhibiting the highest biomarker score were considered for further analysis. Following the establishment of the shortlist, superoxide dismutase 1 (SOD1) and transgelin (TAGLN) autoantibody were identified as two potentially prognostic markers that in combination differentiated high-risk from low-risk patients according to McNemar’s test (p=0.01333).
An in-house immunoassay will be developed to measure SOD1 and TAGLN IgG autoantibody levels using the Bio-Plex® immunoassay platform. AUCs will be calculated for each autoantibody and correlated to risk of progression and survival.