Features Partner Sites Information LinkXpress hp
Sign In
Advertise with Us

Download Mobile App




Liquid Biopsy Test Tracks Treatment-Based ctDNA Changes

By LabMedica International staff writers
Posted on 06 Oct 2021
Metastatic or unresectable disease is identified in approximately 20% of patients presenting with invasive urothelial cancer. More...
In addition, up to 50% of patients will develop metastases following radical cystectomy for clinically localized disease.

Multiagent cisplatin-based chemotherapy is considered standard first-line treatment for these patients. Although urothelial cancer is considered a chemosensitive tumor, metastatic disease is associated with poor prognosis and short-term survival.

Medical Scientists collaborating with those at the Dana-Farber Cancer Institute (Boston, MA, USA) followed 45 participants with metastatic urothelial carcinoma, or mUC, 39 of who underwent immune checkpoint inhibitor, or ICI, therapy while six received cisplatin-based chemotherapy. The median age was 68 years, 79% of patients were male, and 97% had urothelial histology. The majority (82%) received single-agent ICI (PD1/L1 inhibitor). Median duration between pre and post samples was 6.2 months.

Investigators collected plasma samples before therapy and about six months afterwards, then correlated changes in circulating tumor DNA (ctDNA) with objective response using the LiquidHALLMARK assay (Lucence, Palo Alto, CA, USA). Paired pre and post samples underwent ctDNA evaluation with 7 to 30 ng of DNA using an 80-gene panel which employs an amplicon-based NGS assay, including fusions (Lucence, LiquidHALLMARK). The primary objective was to evaluate ctDNA alterations pre- and post-ICI, and to correlate with objective response.

The investigators reported that the most common variants pre- and post-ICI were in TP53 (54% and 49%), TERT (49% and 49%) and BRCA1/2 (36% and 33%). Nine patients were responding to ICI at time of post-ICI blood collection, with seven (78%) showing clearance of ≥1 ctDNA variants, most commonly in TP53, PI3KCA, and BRCA1/2. In 18/20 patients (90%) who were progressing at time of post-ICI collection had emergence of a new alteration, most commonly in BRCA1/2, PI3KCA, CCND2/RB, and TP53. BRCA1 and PIK3CA mutations emerged in only one and zero chemo patients. Patients who cleared TP53 alterations during ICI had a higher likelihood of response compared to those who did not (50% versus 17%).

Guru Sonpavde, MD, a Medical Oncologist and the principal investigator said, “This is somewhat impressive because in most ctDNA platforms, there is not such a high percentage of patients where you see ctDNA alterations.”

The authors concluded that ctDNA alterations were detected in 96% of pre/post-ICI samples overall. Clearance of TP53 alterations during ICI therapy was associated with response, while emergence of BRCA1/2 or PI3KCA variants appeared to be associated with resistance. The study was presented at the European Society for Medical Oncology Virtual Congress held September 16-21, 2021.

Related Links:
Dana-Farber Cancer Institute
Lucence



Gold Member
Quantitative POC Immunoassay Analyzer
EASY READER+
Collection and Transport System
PurSafe Plus®
New
Alcohol Testing Device
Dräger Alcotest 7000
New
Gold Member
Immunochromatographic Assay
CRYPTO Cassette
Read the full article by registering today, it's FREE! It's Free!
Register now for FREE to LabMedica.com and get access to news and events that shape the world of Clinical Laboratory Medicine.
  • Free digital version edition of LabMedica International sent by email on regular basis
  • Free print version of LabMedica International magazine (available only outside USA and Canada).
  • Free and unlimited access to back issues of LabMedica International in digital format
  • Free LabMedica International Newsletter sent every week containing the latest news
  • Free breaking news sent via email
  • Free access to Events Calendar
  • Free access to LinkXpress new product services
  • REGISTRATION IS FREE AND EASY!
Click here to Register








Channels

Molecular Diagnostics

view channel
Image: Left is the original cell image and right is same cell image zoomed in and rendered in the special imaging software (Photo courtesy of FIU)

Brain Inflammation Biomarker Detects Alzheimer’s Years Before Symptoms Appear

Alzheimer’s disease affects millions globally, but patients are often diagnosed only after memory loss and other symptoms appear, when brain damage is already extensive. Detecting the disease much earlier... Read more

Hematology

view channel
Image: New research points to protecting blood during radiation therapy (Photo courtesy of 123RF)

Pioneering Model Measures Radiation Exposure in Blood for Precise Cancer Treatments

Scientists have long focused on protecting organs near tumors during radiotherapy, but blood — a vital, circulating tissue — has largely been excluded from dose calculations. Each blood cell passing through... Read more

Technology

view channel
Image: Conceptual design of the CORAL capsule for microbial sampling in the small intestine (H. Mohammed et al., Device (2025). DOI: 10.1016/j.device.2025.100904)

Coral-Inspired Capsule Samples Hidden Bacteria from Small Intestine

The gut microbiome has been linked to conditions ranging from immune disorders to mental health, yet conventional stool tests often fail to capture bacterial populations in the small intestine.... Read more
Copyright © 2000-2025 Globetech Media. All rights reserved.