According to a new research study, circulating tumour cell (CTC) levels can be used to predict the risk of disease progression in newly diagnosed transplant-eligible multiple myeloma (MM) patients. The findings of this study were published in the Journal of Clinical Oncology.
CTCs are a rare subset of tumour cells that circulate in the bloodstream and can be a powerful tool for disease screening and progression. Garcés et al. evaluated CTC’s prognostic potential in disease risk stratification.
The researchers analysed data from two clinical studies, GEM2012MENO265 and GEM2014MAIN, that included 374 newly diagnosed MM patients receiving treatment including bortezomib, lenalidomide, and dexamethasone induction followed by autologous stem cell transplantation, consolidation, and maintenance. The levels of CTCs were analysed in the peripheral blood, as well as minimal residual disease (MRD) in bone marrow aspirates.
CTCs were detected in most (92%) patients at diagnosis. A modest correlation between CTC levels in the peripheral blood and plasma cells in bone marrow was noted by morphology (ρ =0.41; P <0.001) and flow cytometry (ρ =.46; P <.001). Notably, the percentage of CTC in only peripheral blood (unlike plasma cells) was significantly associated with progression-free survival (PFS, HR, 1.1; 95% CI, 1-1.2; P =0.01) and overall survival (HR, 1.14; 95% CI, 1.01-1.3; P =0.03). Importantly, CTC threshold of 0.01% was an independent predictor of PFS (HR, 2.02; 95% CI, 1.3-3.1; P =0.001). To utilise its prognostic utility, researchers incorporated this criterion in staging factors, including other factors such as albumin less than 3.5 g/dL, β2-microglobulin greater than or equal to 5.5 mg/L, elevated lactate dehydrogenase, and high-risk cytogenetics. Each factor was assigned one point, and it was found that higher scores were associated with poor PFS and OS.
The researchers concluded, “Our data support the inclusion of CTCs into the list of laboratory examinations in peripheral blood at diagnosis and urge considering its utility to enhance the current stratifying systems for patients with newly diagnosed, transplant-eligible MM.”
Garcés J-J, Cedena M-T, Puig N, et al. Circulating tumor cells for the staging of patients with newly diagnosed transplant-eligible multiple myeloma. J Clin Oncol. Published online June 6, 2022. doi:10.1200/JCO.21.