Background and Objective <p>Circulating tumor DNA enables longitudinal monitoring in cancer, but current sequencing-based assays are limited by cost, turnaround time, performance in difficult genomic regions, and infrequent sampling. Universal Signal Encoding PCR (USE-PCR) is a highly multiplexed digital PCR chemistry that enables measurement of up to 32 tumor-informed targets per reaction. Here, we evaluated USE-PCR for dense longitudinal circulating tumor DNA monitoring in patients with metastatic melanoma undergoing immunotherapy.</p> Methods <p>Tumor and plasma sequencing identified subject-specific variants from nine subjects with melanoma, including variants in GC-rich and historically challenging loci such as the <i>TERT</i> promoter. Subject-specific USE-PCR panels were designed using an automated cloud workflow and applied to plasma cell-free DNA and matched peripheral blood mononuclear cell sample DNA, with up to 21 timepoints per subject, collected over a 2-year window. Variant allele fractions were quantified on a commercial digital PCR platform and interpreted with a peripheral blood mononuclear cell genomic DNA background.</p> Conclusions <p>USE-PCR resolved variant-specific circulating tumor DNA trajectories across longitudinal plasma samples. Dense sampling revealed rapid and low-level circulating tumor DNA shifts, including subclonal variants below the 0.2% variant allele fraction that may not be captured through less frequent surveillance intervals. Panels supported the incorporation of new variants without compromising analytical performance.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Individualized Longitudinal ctDNA Monitoring in Melanoma Using Multiplexed USE-PCR

  • Annalara G. Fischer,
  • Hunter A. Miller,
  • Melissa B. Hall,
  • Kavitha Yadannapudi,
  • Lucien Jacky,
  • John Alvarado,
  • Aaron Aguiar,
  • Nathaniel Clark,
  • Paul Belitz,
  • Jeremy Myslinski,
  • Paul Flook,
  • Jerrod J. Schwartz,
  • Mark W. Linder

摘要

Background and Objective

Circulating tumor DNA enables longitudinal monitoring in cancer, but current sequencing-based assays are limited by cost, turnaround time, performance in difficult genomic regions, and infrequent sampling. Universal Signal Encoding PCR (USE-PCR) is a highly multiplexed digital PCR chemistry that enables measurement of up to 32 tumor-informed targets per reaction. Here, we evaluated USE-PCR for dense longitudinal circulating tumor DNA monitoring in patients with metastatic melanoma undergoing immunotherapy.

Methods

Tumor and plasma sequencing identified subject-specific variants from nine subjects with melanoma, including variants in GC-rich and historically challenging loci such as the TERT promoter. Subject-specific USE-PCR panels were designed using an automated cloud workflow and applied to plasma cell-free DNA and matched peripheral blood mononuclear cell sample DNA, with up to 21 timepoints per subject, collected over a 2-year window. Variant allele fractions were quantified on a commercial digital PCR platform and interpreted with a peripheral blood mononuclear cell genomic DNA background.

Conclusions

USE-PCR resolved variant-specific circulating tumor DNA trajectories across longitudinal plasma samples. Dense sampling revealed rapid and low-level circulating tumor DNA shifts, including subclonal variants below the 0.2% variant allele fraction that may not be captured through less frequent surveillance intervals. Panels supported the incorporation of new variants without compromising analytical performance.