Multiplex ligation-dependent probe amplification equals fluorescence in-situ hybridization for the identification of patients at risk for metastatic disease in uveal melanoma

Abstract

In uveal melanoma, loss of chromosome 3 and gain of chromosome 8q are associated with a high risk of metastasis. In this study, we validated the use of multiplex ligation-dependent probe amplification (MLPA) in detecting patients at risk for metastatic disease in comparison with the predictive power of fluorescence in-situ hybridization (FISH). For 64 uveal melanoma samples, the MLPA results of chromosome 3 and 8 were compared with the results obtained by FISH. For seven samples, a single nucleotide polymorphism array was performed to clarify discrepancies. Clinical information together with the histopathology and chromosomal aberrations of chromosomes 1, 3, 6, and 8 were evaluated for correlation with the patients' prognosis. Loss of chromosome 3, loss or gain of 8p, and gain of 8q, found with MLPA, correlated with a significantly lower disease-free survival (P<0.001). On the basis of the clinical outcome, 12 patients would have been classified incorrectly using MLPA results of chromosomes 3 and 8. FISH results led to the same incorrect classification. Four patients with abnormalities of chromosomes 3 and 8 in the tumor, detected with MLPA, are still alive without metastasis. Eight patients without concurrent aberrations of chromosomes 3 and 8 in the tumors died due to metastasis. The sensitivity of MLPA to detect patients at risk for metastatic disease is higher than with the results obtained with FISH (0.795 vs. 0.692). The specificity is equal for both techniques (0.840). MLPA is able to detect patients at risk for metastasis using the results for chromosomes 3 and 8. There is no significant difference in the predictive power of MLPA compared with FISH.

Chromosome 3 Status in Uveal Melanoma: A Comparison of Fluorescence In Situ Hybridization and Single-Nucleotide Polymorphism Array

“…48 In a study using multiplex ligation-dependent probe amplification (MLPA) to detect chromosome 3 loss, 10-year disease-specific mortality was 0% in 133 tumors without chromosome 3 loss. 50 Although these authors did not directly compare MLPA with other techniques, Vaarater et al 51 demonstrated that MLPA was equivalent to FISH for the identification of patients at risk for metastatic disease in uveal melanoma. The sensitivity of MLPA to detect patients at risk for metastatic disease was higher than that of FISH (0.795 vs. 0.692) but the specificity was equal for both techniques (0.840).…”

“…The sensitivity of MLPA to detect patients at risk for metastatic disease was higher than that of FISH (0.795 vs. 0.692) but the specificity was equal for both techniques (0.840). 51 Onken et al 18 reported that loss of heterozygosity of chromosome 3 detected by SNP-A was superior to that of FISH in predicting metastatic outcome. However, FISH analysis was suboptimal in that study because investigators used paraffinembedded tissue (replete with truncation artifacts) and counted only 100 cells.…”

Prognostication in eye cancer: the latest tumor, node, metastasis classification and beyond

“…[31][32][33] At present, the method of choice for initial chromosomal analysis is multiple ligation probe amplification (MLPA), which probes multiple loci across several chromosomes. [31][32][33][34] If the result contradicts the histopathological grade, reanalysis with methods such as complete genomic hybridization is advisable. 31,33 Advantages of MLPA include low cost and data obtained simultaneously from several chromosomes other than chromosome 3.…”

Molecular Pathology of Uveal Melanoma

“…These alterations were initially identified by standard karyotypic analyses. 94 79,[125][126][127] and singlenucleotide polymorphisms (SNPs). 109,[128][129][130][131][132] The above-mentioned chromosomal alterations in primary UM are clinically relevant because of their correlation with the risk of metastatic death.…”