Contrast-enhanced ultrasound imaging characteristics of intrahepatic cholangiocarcinoma with actionable gene variants detected by comprehensive cancer gene panel testing.

BACKGROUND

Cancer gene panel testing (CGP) helps comprehensively analyze a large number of genes, extracting genetic information from the genome profile to aid treatment plans and drug therapy. Advances in drug therapy and surgical treatment for intrahepatic cholangiocarcinoma (ICC) have improved patient outcomes; however, it remains a typical intractable cancer with a poor prognosis. ICC is one of the key tumors for which effective treatment may be identified through CGP testing. This study aimed to identify ICC harboring actionable genetic variants using contrast-enhanced ultrasonography (CE-US).

METHODS

We enrolled 26 ICC patients who underwent CE-US before chemotherapy or surgery. Three ultrasound specialists reviewed the images by consensus and assessed the imaging features, including vascularity. Pathological data were reviewed after diagnosis using CE-US. We retrospectively analyzed distinctive CE-US findings in patients with ICC with actionable genetic variants.

RESULTS

Twelve ICC patients had actionable gene variants, including four FGFR2 fusions, one FGFR2 rearrangement, six IDH1 mutations, and one BRAF V600E mutation. Univariate analysis showed significant differences in bile duct invasion (p = 0.0217) and blood vessel penetration within the tumor (p = 0.0012). Multivariable logistic regression identified blood vessel penetration within the tumor (OR = 18.275; 95% CI: 1.331-250.925; p = 0.0297) as independently associated with actionable gene variants.

CONCLUSION

Patients with ICC and blood vessel penetration on CE-US should be considered for CGP testing.