Large pooled analysis reveals prognostic utility of circulating tumour cells in MM

A large study on circulating tumour cells (CTCs) in patients with previously untreated multiple myeloma (MM) demonstrated their prognostic utility for progression-free survival (PFS), even when other factors, such as cytogenetics and the International Staging System, were taken into account.

“Since there is no consensus on how to stratify patients with MM based on CTCs, we performed an analysis among 2,466 patients with newly diagnosed MM to investigate this matter,” said Dr Luca Bertamini (University of Turin, Italy) [1]. The study comprised a diverse population: 45% of the patients were 65 years or older, 48% were ineligible for transplant, and 59% participated in clinical trials.

After a median follow-up of 56.8 months, the median CTC level was 0.017%, with no observed differences between the datasets from the 6 participating European countries. Dr Bertamini highlighted that continuous CTC levels were prognostic of PFS outcomes. “We were able to discriminate between 5 groups of patients with different CTC levels in terms of PFS,” he said. “Patients with high CTC levels had a significantly shorter PFS duration than those with low CTC levels [P<0.0001]. Moreover, CTC level was an independent predictor for PFS [HR 1.18; 95% CI 1.12-1.24; P<0.001].” The research team determined the optimal CTC cut-off level for clinical use at 0.02%. “Patients with CTC levels of 0.02% or lower clearly outperformed patients with CTC levels above 0.02% in terms of PFS,” clarified Dr Bertamini. CTC levels were prognostic for PFS across clinical trial and real-world subgroups, as well as for transplant-eligible and transplant-ineligible patients.

Thus, CTC may serve as an independent prognostic factor for survival outcomes in patients with MM, finetuning the risk assessment for the population, concluded Dr Bertamini. Incorporating CTC levels into standard risk stratification may improve the prognostic ability of these classification tools.

1. Bertamini L, et al. Circulating tumour cells for the staging of multiple myeloma: a European pooled analysis of 2,446 newly diagnosed patients. S199, EHA2025 Congress, 12–15 June, Milan, Italy.

Medical writing support was provided by Robert van den Heuvel.
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Posted on 17 June 202517 June 2025