Heterogeneity Among Circulating Tumor Cells in Advanced Melanoma
Posted: Thursday, January 23, 2020
A molecular study presented at the 2019 International Congress of The Society for Melanoma Research (SMR) in Salt Lake City revealed “extraordinary” heterogeneity among melanoma circulating tumor cells, with multiple nonoverlapping subpopulations. “Despite the high phenotypic and molecular heterogeneity of melanoma [circulating tumor cells], multimarker-derived [circulating tumor cell] scores could serve as viable tools for prognostication and treatment response monitoring in patients with metastatic melanoma,” explained Elin Gray, PhD, of Edith Cowan University in Joondalup, Australia, and colleagues.
Using three microfluidic devices to recover circulating melanoma cells, the researchers analyzed blood samples from 43 patients with metastatic melanoma. They utilized a combination of immunocytochemistry and transcript analyses of 5 genes by reverse transcriptase polymerase chain reaction (PCR) and 19 genes by droplet digital PCR. The circulating tumor DNA from each patient blood sample was assessed by droplet digital PCR to evaluate tumor-specific mutations.
Dr. Gray and colleagues found that circulating tumor cell scores correlated with plasma circulating tumor DNA concentrations, and both markers expressed similar pharmacodynamic changes upon treatment initiation. Additionally, the presence of detectable circulating tumor cells using the multimarker approach seemed to be associated with shorter overall and progression-free survival.
Disclosure: For full disclosures of the study authors, visit societymelanomaresearch.org/congress.