Logo image
Peritoneal Cell-Free Tumor DNA as Biomarker for Peritoneal Surface Malignancies
Journal article   Peer reviewed

Peritoneal Cell-Free Tumor DNA as Biomarker for Peritoneal Surface Malignancies

Katie M Leick, Austin G Kazarian, Maheen Rajput, Ann Tomanek-Chalkley, Ann Miller, Hannah R Shrader, Ashley McCarthy, Kristen L Coleman, Pashtoon M Kasi and Carlos H F Chan
Annals of surgical oncology, Vol.27(13), pp.5065-5071
12/2020
DOI: 10.1245/s10434-020-08832-9
PMCID: PMC9731140
PMID: 32648179

View Online

Abstract

Disease burden in patients with peritoneal carcinomatosis (PC) is difficult to estimate. We evaluate whether peritoneal cell-free tumor DNA can be used as a measure of disease burden. Malignant ascites or peritoneal lavage fluids were collected from patients with PC under approved IRB protocol. Cell-free DNA was extracted from peritoneal fluid. Droplet digital PCR (ddPCR) was performed using a commercially available KRAS G12/G13 screening kit. Mutant allele frequency (MAF) was calculated based on the numbers of KRAS wild-type and mutant droplets. Clinicopathological, treatment and outcome data were abstracted and correlated with MAF of cell-free KRAS mutant DNA. Cell-free KRAS mutant DNA was detected in 15/37 (40%) malignant peritoneal fluids with a MAF of 0.1% to 26.2%. While peritoneal cell-free KRAS mutant DNA was detected in all the patients with KRAS mutant tumors (N = 10), 3/16 (19%) patients with KRAS wild-type tumors also had peritoneal cell-free KRAS mutant DNA. We also found that 71% (5/7) of patients with disease amenable to cytoreductive surgery (CRS) had a MAF of < 1% (median: 0.5%, range: 0.1-4.7%), while 75% (6/8) of patients with unresectable disease had a MAF of > 1% (median: 4.4%, range: 0.1-26.2%). This pilot proof-of-principle study suggests that peritoneal cell-free tumor DNA detected by ddPCR may enable prediction of disease burden and a measure of disease amenable to CRS in patients with PC.
Biomarkers, Tumor - genetics Circulating Tumor DNA Humans Peritoneal Neoplasms - diagnosis Peritoneal Neoplasms - genetics Polymerase Chain Reaction

Details

Metrics

Logo image