Molecular Detection of Metastatic Melanoma Cells in Cerebrospinal Fluid in Melanoma Patients

Abstract

Melanoma frequently metastasizes to the central nervous system (CNS). The diagnosis of CNS metastases typically is made following the onset of clinical symptoms. Thus, more sensitive diagnostic approaches are needed to identify subclinical CNS metastases. Currently, standard cytologic analysis of the cerebrospinal fluid (CSF) is limited by its poor sensitivity. A more sensitive assay was therefore developed using multiple reverse transcriptase-polymerase chain reaction (RT-PCR) markers. CSF was collected and assessed by RT-PCR for three known melanoma-associated markers (MAGE-3, MART-1, and tyrosinase) to detect occult metastatic melanoma cells in the CSF of 37 American Joint Committee on Cancer (AJCC) stage IV melanoma patients. Cytologic analysis of CSF was performed on all patients, and immunohistochemistry (IHC) analysis was performed on 33 CSF samples using anti-S100 and anti-HMB-45 antibodies. Only one patient (3%) had tumor-positive CSF cytology and IHC upon entry into the study, whereas 12 patients (32%) were positive for at least one RT-PCR marker. The correlation between CSF RT-PCR positivity of MART-1 and/or MAGE-3 and the development of CNS metastases at 3 mo was significant (p = 0.04). Fifteen of 37 patients (41%) had either positive MRI and/or positive RT-PCR results. Multimarker RT-PCR is more informative and sensitive than cytology/IHC in assessing the CSF of melanoma patients.

Incipient Melanoma Brain Metastases Instigate Astrogliosis and Neuroinflammation

“…The presence of tumor cells in CSF was previously reported to be associated with advanced disease: cytologic and molecular analysis detected melanoma cells in CSF from stage IV melanoma patients with brain metastases (33). Here we demonstrate that CSF can be utilized to detect melanoma-derived transcripts in exosomes, rather than in tumor cells seeded in the CSF, thus implicating this analysis in early diagnosis and monitoring of occult micrometastases.…”

Quantification of tumor-derived cell free DNA(cfDNA) by digital PCR (DigPCR) in cerebrospinal fluid of patients with BRAFV600 mutated malignancies

“…Possible causes of false negatives include minimal tumor cell exfoliation into the CSF, blockage in CSF flow, and the uneven distribution of malignant cells in CSF [15, 16]. Investigators have applied other, non-quantitative methods to detect malignant cells in the CSF such as multi-marker reverse transcriptase-PCR assay [17]. However these non-quantitative methods have relatively low sensitivity and do not allow for easy comparison of tumor burden across serial samples.…”

Tyrosinase expression in the peripheral blood of stage III melanoma patients is associated with a poor prognosis: a clinical follow-up study of 110 patients

“…Its role as a molecular marker in melanoma patients was first proposed by Smith et al (1991) in the early 1990s; since then, tyrosinase expression has been applied for the detection of malignant melanoma cells in sentinel lymph node biopsies and investigated in peripheral blood, bone marrow and biological fluids (Ghossein et al, 1998;Blaheta et al, 2001;Hoon et al, 2001).…”