Metastatic disease to the liver: Locoregional therapy strategies and outcomes

Table 1 Summary of locoregional therapy options for metastatic disease to the liver

Modality	Techniques	Risks
TAE	Particulate or liquid embolic agents	PES, liver abscess, liver biloma, liver failure
TACE	Conventional emulsified chemotherapeutic agent (c-TACE) or drug-eluting beads (DEB-TACE)	PES, liver abscess, liver biloma, liver failure
TARE	Yttrium-90 radioisotope loaded on microspheres	REILD, PRS, liver failure, liver abscess, liver biloma
Ablation	Radiofrequency, microwaves, laser, cooling, alternating and direct current	PAS, bleeding, damage to surrounding structures

PES: Post-embolization syndrome; REILD: Radioembolization-induced liver disease; PRS: Post-radioembolization syndrome; PAS: Post-ablation syndrome; TAE: Transarterial embolization; TACE: Transarterial chemoembolization; TARE: Transarterial radioembolization.

Table 2 Applications and outcomes of locoregional therapies by tumor type

Modality	Applications and outcomes
TAE	First-line for unresectable symptomatic well-differentiated NELM refractory to medical therapy[19]
	Improved OS and PFS vs first-line chemotherapy in unresectable CRLM[39,40]
TACE	Comparable tumor response and OS vs first-line chemotherapy in neoadjuvant setting for CRLM[41]
	Improved OS and tumor control when used as adjunctive therapy in BCLM[42-44]
	Comparable overall survival to systemic chemotherapy in UMLM[45,46]
	In IHC, DEB-TACE and chemotherapy have comparable OS[47] and DEB-TACE improves OS when added to chemotherapy[48,49]
	TARE with first-line chemotherapy offers a survival benefit in CRLM[50], IHC[51]
TARE	Provides survival benefit in CRLM after failure of two lines of chemotherapy[52]
	TARE plus chemotherapy improves downstaging vs chemotherapy alone in CRLM[13,53], IHC[51]
	Increases OS in unresectable CRLM compared to chemotherapy alone[54]
Ablation	RFA[55] and MWA[56] have comparable OS to surgical resection in CRLM
	RFA with resection has comparable OS to two-stage hepatectomy in CRLM[57], NELM[58]
	Fewer adverse events, longer PFS, and comparable OS vs resection in BCLM[12,59]

NELM: Neuroendocrine cancer with liver metastasis, CRLM: Colorectal cancer with liver metastasis, BCLM: Breast cancer with liver metastasis, UMLM: Uveal melanoma with liver metastasis, IHC: intrahepatic cholangiocarcinoma, OS: Overall survival, PFS: Progression-free survival; TAE: Transarterial embolization; TACE: Transarterial chemoembolization; TARE: Transarterial radioembolization.