Dr. Tom Wei‑Wu Chen (National Taiwan University Hospital, Taiwan) set that tone from the start: “So talking about rare cancers, obviously it's rare.”. Rare cancers have fewer standard systemic treatment options and less evidence supporting optimal management. He highlighted the value of liquid biopsy in this setting and emphasized the need for greater interdisciplinary and multidisciplinary collaboration. Soft tissue sarcoma exemplifies these challenges, as it is both uncommon and highly heterogeneous, encompassing diverse histologies and genomic profiles. This complexity, he noted, makes serial blood-based monitoring especially useful.
He centered the discussion on a common clinical dilemma in advanced sarcoma: “what to do after first‑line anthracycline chemotherapy achieves disease control but cannot safely continue due to cumulative toxicity”. The MELODY study was designed to address this gap as a multinational randomized phase II trial, comparing maintenance pegylated liposomal doxorubicin versus active surveillance in patients with stable or responding disease after at least five cycles of anthracycline.
MELODY incorporates exploratory biomarkers, including ctDNA monitoring and optional baseline imaging assessments. In collaboration with Gene Solutions, the trial uses a tumor-informed ctDNA approach as one of its important biomarkers. Dr. Chen emphasized the importance of detailed mutation-level reporting, noting that results are more clinically useful when they specify the variants being tracked rather than simply providing a positive or negative result: “They do not just give you a positive or negative result, they also tell you which mutations they are counting to say the sample positive.” he said.
In a field where imaging may appear stable despite frequent early relapses, this design aims to figure out whether molecular signals can better guide maintenance strategies, refine surveillance, and predict progression—turning uncertainty in rare cancers into more actionable knowledge.
<iframe width="560" height="315" src="https://www.youtube.com/embed/Ncg5gTf1r2o" title="Liquid Biopsy in Rare Cancers: ctDNA Monitoring in Soft Tissue Sarcoma – Insights from MELODY" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
