Serum Amyloid A and Lipoprotein Associated Phospholipase A(2) Levels in Patients with Malign Melanoma: Correlations with Clinical Assessment and Stage

Objective: The lack of validated, sensitive, and specific biomarkers for early diagnosis and follow-up of patients with malign melanoma (MM) is a major problem today. In this study, we aimed to investigate the correlations of two inflammatory biomarkers-serum amyloid A (SAA) and lipoprotein associated phospholipase A 2 (Lp-PLA(2))-in clinical follow-up and staging of MM. Methods: Lactate dehydrogenase (LDH) and C-reactive protein (CRP) (Routine), SAA and S100B (ELISA), and Lp-PLA(2) (PLAC (R) Test) activity levels were examined in histologically and clinically confirmed MM patients (n=131) and in healthy controls (n=27). Results: Sedimentation rate and LDH, CRP, S100B, SAA, Lp-PLA(2) activities were found to be significantly higher in MM patients compared to control group (p<0.05). SAA showed the strongest correlation with disease stage (Spearman's correlation coefficient=0.622, p=0.000). Receiver operating characteristic analysis revealed that SAA exhibited the largest area under the curve=0.984, p=0.000, highest sensitivity (95%) and specificity (93%). Pearson's test indicated a weak positive correlation between SAA levels and Lp-PLA(2) activity (r=0.311, p=0.000). Conclusion: This is the first study to evaluate the activity of inflammatory biomarker Lp-PLA(2) in melanoma patients. Both SAA and Lp-PLA(2) were in highest levels in stage 4 patients, and they are thought to be candidate biomarkers to be used in detecting tumor progression. According to our results, SAA is the biomarker which correlates best with disease stage in MM.