The Emerging Role of Circulating Tumor DNA in Non-Colorectal Gastrointestinal Cancers

Utility of circulating tumor DNA in secondary liver malignancies: What we know and what is to come

Secondary liver malignancies are a serious and challenging global health concern. Secondary metastasis to the liver is most commonly from colorectal cancer that has metastatically spread through splanchnic circulation. Metastatic diseases can portend poor prognosis due to the progressive nature typically found on detection. Improvements in detection of disease, monitoring therapy response, and monitoring for recurrence are crucial to the improvement in the management of secondary liver malignancies. Assessment of ctDNA in these patient populations poses an opportunity to impact the management of secondary liver malignancies. In this review, we aim to discuss ctDNA, the current literature, and future directions of this technology within secondary liver malignancies.

Circulating tumor DNA in management of primary liver malignancy: A review of the literature and future directions

Primary liver malignancies are a serious and challenging global health concern. The most common primary tumors are hepatocellular carcinoma and cholangiocarcinoma. These diseases portend poor prognosis when presenting with progressive, extensive disease. There is a critical need for improved diagnosis, therapeutic intervention, and monitoring surveillance in liver-related malignancies. Liquid biopsy using ctDNA provides an opportunity for growth within these domains for liver-related malignancy. However, ctDNA is relatively understudied in this field compared with other solid tumor types, possibly due to the complex nature of the pathology. In this review, we aim to discuss ctDNA, the current literature, and future directions of this technology within primary liver malignancies.

Whole-Genome DNA Methylation Profiling of Intrahepatic Cholangiocarcinoma Reveals Prognostic Subtypes with Distinct Biological Drivers

Intrahepatic cholangiocarcinoma (iCCA) is the second most prevalent primary liver cancer. Although the genetic characterization of iCCA has led to targeted therapies for treating tumors with FGFR2 alterations and IDH1/2 mutations, only a limited number of patients can benefit from these strategies. Epigenomic profiles have emerged as potential diagnostic and prognostic biomarkers for improving the treatment of cancers. In this study, we conducted whole-genome bisulfite sequencing on 331 iCCAs integrated with genetic, transcriptomic, and proteomic analyses, demonstrating the existence of four DNA methylation subtypes of iCCAs (S1-S4) that exhibited unique postoperative clinical outcomes. The S1 group was an IDH1/2 mutation-specific subtype with moderate survival. The S2 subtype was characterized by the lowest methylation level and the highest mutational burden among the four subtypes and displayed upregulation of a gene-expression pattern associated with cell cycle/DNA replication. The S3 group was distinguished by high interpatient heterogeneity of tumor immunity, a gene-expression pattern associated with carbohydrate metabolism, and an enrichment of KRAS alterations. Patients with the S2 and S3 subtypes had the shortest survival among the four subtypes. Tumors in the S4 subtype, which had the best prognosis, showed global methylation levels comparable to normal controls, increased FGFR2 fusions/BAP1 mutations, and the highest copy-number variant burdens. Further integrative and functional analyses identified GBP4 demethylation, which is highly prevalent in the S2 and S3 groups, as an epigenetic oncogenic factor that regulates iCCA proliferation, migration, and invasion. Together, this study identifies prognostic methylome alterations and epigenetic drivers in iCCA.

SIGNIFICANCE

Characterization of the DNA methylome of intrahepatic cholangiocarcinoma integrated with genomic, transcriptomic, and proteomic analyses uncovers molecular mechanisms affected by genome-wide DNA methylation alterations, providing a resource for identifying potential therapeutic targets.

Pemigatinib for patients with previously treated, locally advanced or metastatic cholangiocarcinoma harboring FGFR2 fusions or rearrangements: A joint analysis of the French PEMI-BIL and Italian PEMI-REAL cohort studies

BACKGROUND

Pemigatinib is approved for patients with pretreated, locally advanced or metastatic CCA harboring FGFR2 rearrangements or fusions. We aim to assess the effectiveness and safety of pemigatinib in real-world setting.

MATERIAL AND METHODS

A joint analysis of two multicentre observational retrospective cohort studies independently conducted in France and Italy was performed. All consecutive FGFR2-positive patients affected by CCA and treated with pemigatinib as second- or further line of systemic treatment in clinical practice, within or outside the European Expanded Access Program, were included.

RESULTS

Between July 2020 and September 2022, 72 patients were treated with pemigatinib in 14 Italian and 25 French Centres. Patients had a median age of 57 years, 76% were female, 81% had ECOG-PS 0-1, 99% had intrahepatic CCA, 74% had ≥ 2 metastatic sites, 67% had metastatic disease at diagnosis, while 38.8% received ≥ 2 previous lines of systemic treatment. At data cut-off analysis (April 2023), ORR and DCR were 45.8% and 84.7%, respectively. Median DoR was 7 months (IQR: 5.8-9.3). Over a median follow-up time of 19.5 months, median PFS and 1-year PFS rate were 8.7 months and 32.8%. Median OS and 1-year OS rate were 17.1 months and 60.6%. Fatigue (69.4%), ocular toxicity (68%), nail toxicities (61.1%), dermatologic toxicity (41.6%) hyperphosphataemia (55.6%), stomatitis (48.6%), and diarrhea (36.1%) were the most frequent, mainly G1-G2 AEs. Overall incidence of G3 AEs was 22.2%, while no patient experienced G4 AE. Dose reduction and temporary discontinuation were needed in 33.3% and 40.3% of cases, with 1 permanent discontinuation due to AEs.

CONCLUSIONS

These results confirm the effectiveness and safety of pemigatinib in a real-world setting.