TY - JOUR T1 - Liquid Biopsy Cell-free DNA Biomarkers in Patients With Oligometastatic Colorectal Cancer Treated by Ablative Radiotherapy JF - Anticancer Research JO - Anticancer Res SP - 829 LP - 834 DO - 10.21873/anticanres.14835 VL - 41 IS - 2 AU - MASAKI NAKAMURA AU - SHUN-ICHIRO KAGEYAMA AU - MASAHIDE SEKI AU - AYAKO SUZUKI AU - MASAYUKI OKUMURA AU - HIDEHIRO HOJO AU - ATSUSHI MOTEGI AU - TETSUO AKIMOTO Y1 - 2021/02/01 UR - http://ar.iiarjournals.org/content/41/2/829.abstract N2 - Background/Aim: To investigate the usefulness of cell-free DNA (cfDNA) in patients with oligometastasis. Patients and Methods: This study included oligometastatic colorectal cancer (CRC) patients who underwent ablative irradiation using stereotactic body radiotherapy or proton beam therapy for metastatic lesions at a single institution. cfDNA was purified from the plasma of pretreated patients and gene mutations were analyzed by next-generation sequencing. Progression-free survival (PFS) was statistically compared according to gene mutation, clonality or allele frequency. Results: A total of 20 patients were analyzed. Mutations were detected in the following genes; TP53 (45%), APC (40%), KRAS (15%), PIK3CA (15%), NF1 (5%), BRCA1 (5%), ERBB2 (5%), FBXW7 (5%), KIT (10%), and HRAS (10%). Patients with multi-clonality of gene mutation showed tendency for poor PFS (p=0.07). Among 7 patients whose metastatic site was the lung, those with no cfDNA detected had significantly better PFS than those with cfDNA (p=0.02). Conclusion: cfDNA profiles could be predictive tools for early recurrence of oligometastatic CRC patients after ablative radiotherapy. ER -