Imagine a world where a quick blood draw could tell doctors if lymphoma is truly gone or lurking in the shadows, far more accurately than expensive imaging scans. This isn't science fiction—it's the promise of a real-world study that's shaking up cancer care for patients everywhere.
Exciting new evidence from actual patient data suggests that checking for circulating tumor DNA, or ctDNA, after treatment wraps up gives a clearer picture of event-free survival (EFS)—that's the time without the disease worsening or returning—than traditional PET-CT scans. This breakthrough holds huge potential for tailoring treatment and catching relapses early, across various types of lymphoma. But here's where it gets controversial: Could this simple blood test someday replace the bulky, radiation-heavy scans we've relied on for decades? Stick with me as we dive into the details of this eye-opening research, and you'll see why it might just change the game.
In a retrospective look at real-life cases, presented at the 2025 ASH Annual Meeting and Exposition (which you can check out at https://www.onclive.com/conference/ash), researchers found that ctDNA at the end of treatment (EOT) strongly forecasted outcomes for lymphoma patients, no matter the subtype.1 Picture ctDNA as tiny pieces of DNA shed by cancer cells into the bloodstream—it's like a molecular breadcrumb trail that doctors can follow to detect hidden disease.
The results were striking: In the group with no detectable ctDNA minimal residual disease (MRD)—meaning the cancer seemed cleared—median EFS wasn't even reached (NA), compared to just 1.97 months for those still showing ctDNA (n=19; adjusted hazard ratio [HR] 22.43; 95% CI 6.76-74.45; P<.0001). At 12 and 24 months, the HRs were 0.83 (95% CI 0.71-0.98) and 0.79 (95% CI 0.64-0.96) for the ctDNA-negative folks, versus a dismal 0.05 (95% CI 0.01-0.35) and 0.00 for the positive group. This isn't just numbers—it's about giving patients hope and doctors better tools.
“As Natalie Galanina, MD, the lead author and a clinician at UPMC Hillman Cancer Center in Pittsburgh, Pennsylvania, explained during her talk, 'EOT ctDNA status can clear up confusing imaging results and spot relapses sooner.' She went on to say, 'ctDNA patterns during treatment provide live updates on how well therapy is working in first-line care, and they even hint at success with CAR T-cell therapy.' For beginners, think of ctDNA as a high-tech spy gadget in the fight against cancer—it's sensitive enough to pick up the faintest signals of trouble.
And this is the part most people miss: The study didn't just show ctDNA's strength—it outperformed PET-CT in key ways. Here are the main takeaways from this real-world investigation:
- ctDNA status post-treatment was a powerful predictor, with negative MRD tied to much longer EFS in all lymphoma types.
- It beat PET-CT at spotting leftover disease and predicting future relapses.
- How quickly ctDNA disappeared (early or later) linked to better EFS, making it a potential staple in regular check-ups and monitoring.
So, what sparked this research? Well, personalized ctDNA tests—tailored to each patient's unique tumor—have already proven their worth in diffuse large B-cell lymphoma (DLBCL), a common aggressive type. But their role in other lymphomas hadn't been explored much.2 To fill that gap, the team gathered real-world data on MRD detection and ctDNA disappearance patterns from patients with new or returning lymphoma across 14 subtypes.1
Galanina described the tool they used, Signatera, as a custom test: 'It's personalized, sequencing both the tumor and normal tissue to create a patient-specific probe. This lets us track ctDNA in blood plasma with incredible sensitivity and accuracy, avoiding false alarms.' Imagine it like a fingerprint for cancer—unique to each person, so doctors can monitor precisely.
How did they set up the study to test ctDNA's value across different lymphomas? They analyzed 1,105 blood samples from 144 patients, covering a mix of aggressive (123 cases) and indolent (21) types. This included T-cell (13) and B-cell (110) lymphomas, plus specific ones like follicular (10), marginal zone (5), and cutaneous T-cell (6). The group was diverse, mirroring everyday patients: median age 61 (18-84), mostly men (77, or 53%), with many in advanced stage IV (75, or 56%). Performance scores (how well they functioned daily) were mostly good (0 or 1), and prognostic scores varied.
Treatments ranged from standard combos like Pola-R-CHP (6 cases, 4.3%) and R-CHOP (72, 51%) to others like R-EPOCH (14, 10%) and various rituximab options (17, 12%). They checked ctDNA at a median of 7 points per patient (1-32), with follow-up for EFS and overall survival (OS) averaging 20-21 months (1-108).
Before treatment, ctDNA showed up in 94% of cases, with higher levels in aggressive types (about 100 molecules per mL) versus indolent (20), probably reflecting differences in tumor spread.
Now, here's where things get intriguing—and potentially divisive. The data showed ctDNA outshone traditional imaging for gauging response. For instance, patients with clear PET-CT scans at EOT (35 cases) had unmeasured median EFS, versus 5.16 months for those with positive scans (25; adjusted HR 8.68; 95% CI 2.41-31.29; P=.0010). But ctDNA-negative patients (44) fared even better: NA EFS versus 2.04 months for positives (16; adjusted HR 49.77; 95% CI 9.91-250.02; P<.0001).
Digging deeper, even among PET-negative patients, ctDNA-negative ones (32) had NA EFS versus 2.76 months for positives (3; HR 45.29; 95% CI 4.63-443.27; P=.0011). And for PET-positive folks, ctDNA-negatives (12) still did well (NA EFS) compared to positives (13; HR 12.26; 95% CI 3.23-46.59; P=.0002).
As Galanina put it, 'PET-positive results at EOT are tricky—most patients get extra treatment. But our findings suggest 75% of PET-positive, ctDNA-negative patients won't progress, possibly sparing them unnecessary therapy.' She added, 'For PET-negative but ctDNA-positive patients, closer watching is key. For PET-positive and ctDNA-negative, observation might suffice, or confirm with a biopsy to check if the scan picked up something harmless.' This could spark debate: Is it ethical to forgo more scans or tests based on ctDNA, especially with small sample sizes here?
In advanced analysis, ctDNA emerged as the top predictor of EFS, even after accounting for age, histology, and stage (P<.001).
ctDNA clearance during initial therapy also predicted success across subtypes. Patients who cleared it (48) had NA median EFS versus 2.05 months for non-clearers (12; adjusted HR 8.57; 95% CI 2.55-28.81; P=.0005). Breaking it down: NA for cycle 1 clearers (14), NA for delayed (34), and 2.05 for none. HRs for no clearance were 20.95 (vs. cycle 1; 95% CI 2.09-211.11; P=.0097) and 7.45 (vs. delayed; 95% CI 2.22-24.98; P=.0011).
'Quick clearance,' Galanina noted, 'could mean scaling back treatment for elderly or sick patients, reducing side effects.' But here's the controversial twist: What if early clearance leads to overtreatment in some cases? The study hints at possibilities, but more data is needed.
Could ctDNA predict CAR T-cell therapy success? Absolutely, per the findings. Clearance post-treatment often meant lasting remission at one year. One outlier relapsed after a year but showed ctDNA beforehand, underscoring the need for ongoing tests. 'Single checks might not cut it—regular monitoring could catch trouble years later,' Galanina advised.
In wrapping up, she emphasized, 'MRD testing with ctDNA should become standard for personalizing lymphoma care.'
Full disclosure: Galanina reported no financial ties.
References:
1. Galanina N, Iqbal M, Nousome D, et al. Real-world evaluation of ctDNA for risk stratification across the spectrum of both aggressive and indolent lymphomas. Blood. 2025;146(suppl 1):281. doi:10.1182/blood-2025-281
2. Narkhede M, Tomassetti S, Iqbal M, et al. Tumor-informed ctDNA assessment as a valuable prognostic and predictive biomarker in diffuse large B-cell lymphoma. Front Oncol. Published online July 29, 2024. doi:10.3389/fonc.2024.1407003
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What do you think about this? Is ctDNA ready to revolutionize lymphoma monitoring, or should we stick with proven imaging like PET-CT? Do you agree that it could reduce overtreatment, or worry about missing something important? Share your opinions in the comments—let's discuss!
