Does Bead Size Affect Patient Outcome in Irinotecan-Loaded Beads Chemoembolization Plus Systemic Chemotherapy Regimens for Liver-Dominant Colorectal Cancer? Results of an Observational Study

Chemoembolization Beyond Hepatocellular Carcinoma: What Tumors Can We Treat and When?

Liver metastases are the most common malignancy found in the liver and are 20 to 40 times more common than primary hepatic tumors, including hepatocellular carcinoma. Patients with liver metastases often present with advanced disease and are not eligible for curative-intent surgery or ablative techniques. The unique hepatic arterial blood supply of liver metastases allows interventional radiologists to target these tumors with transarterial therapies. Transarterial chemoembolization (TACE) has been studied in the treatment of liver metastases originating from a variety of primary malignancies and has demonstrated benefits in terms of hepatic progression-free survival, overall survival, and symptomatic relief, among other benefits. Depending on the primary tumor from which they originate, liver metastases may have different indications for TACE, may utilize different TACE regimens and techniques, and may result in different post-procedural outcomes. This review offers an overview of TACE techniques and specific considerations in the treatment of liver metastases, provides an in-depth review of TACE in the treatment of liver metastases originating from colorectal cancer, neuroendocrine tumor, and uveal melanoma, which represent some of the many tumors beyond hepatocellular carcinoma that can be treated by TACE, and summarizes data regarding when one should consider TACE in their treatment algorithms.

Drug-Eluting Bead, Irinotecan (DEBIRI) Therapy for Refractory Colorectal Liver Metastasis: A Systematic Review

Colorectal cancer and related mortality present a profound challenge in its management, even in this modern age. Even today, colorectal cancer-related deaths rank third in the world. Despite having multiple lines of chemotherapy, combined with radiotherapy and chemoembolization techniques, after or before surgical resection, the five-year survival rate is approximately 20%. Drug-eluting bead, irinotecan (DEBIRI) is a new technique that involves embolization of the feeding vessels to the tumour and delivering irinotecan for its chemotherapeutic effects. A significant amount of literature compares DEBIRI as an adjunct to various lines of chemotherapy. However, so far, not much data are available on DEBIRI as a singular treatment for those patients who have had multiple chemotherapies and still progressing and are not fit for liver resection. In this systematic review, we aim to highlight and bring together the results of those studies that focused on this specific patient group. A systematic search of the literature involving three large databases (published between January 2017 and July 2022), excluding languages other than English, was conducted to identify articles documenting patients who had disease progression despite chemotherapy and were not fit for surgical resection. The level of evidence and the quality check were assessed by two independent reviewers, and consensus with the senior author resolved disagreements. Out of seven studies that met the final criteria, we found a pooled cohort of 302 patients. The mean age of the patients was 61.2 years, ranging from 40.7 to 84 years. The most commonly used DEBIRI beads were M1 (70-150 um) and M2 (100-300 um), but two studies reported the use of 40 um as well. The total number of DEBIRI treatments performed in our pooled cohort was 904. The majority of the studies reported only G1/G2 toxicities among the patients, with maximal toxicity of G4 in a few selected patients. The median overall survival in our pooled cohort was 19.52 months. The median progression-free survival in our data was 5.76 months. Our systematic review concludes that DEBIRI is undoubtedly a useful treatment modality with an acceptable toxicity profile. This treatment offers a good overall survival benefit for refractory colorectal liver metastasis.

Prospective Series of Transarterial Chemoembolization of Metastatic Colorectal Cancer to the Liver with 30-60 μm Microspheres Loaded with Irinotecan

PURPOSE

To describe safety and clinical outcomes among patients with metastatic colorectal cancer (mCRC) to the liver treated with transarterial chemoembolization with HepaSphere™ Microspheres 30-60 μm loaded with irinotecan (ΙRI-HEP-TACE).

MATERIAL AND METHODS

In this prospective study (NCT04866290), 100 adults with confirmed mCRC to the liver who were ineligible for resection were enrolled and followed up to 24 months or death. Study outcomes among Salvage (patients not tolerating more cycles of chemotherapy) and Non-salvage patients included overall survival (OS), progression-free survival (PFS), objective response (OR), objective response rate (ORR), best tumor response (BTR), adverse events (AEs), and pharmacokinetics of irinotecan and its active metabolite, 7-ethyl-10-hydroxy-camptothecin (SN38).

RESULTS

The median age was 66 years (range: 31-89). Median OS was 15.08 months (95% confidence interval [CI]: 12.33-17.25). PFS was 8.52 months (95% CI: 6.0-9.0; p < 0.001). ORR was 42.2% (95% CI: 31.57-53.50) and 35.9% (95% CI: 25.57-47.62) based on modified RECIST (Response Evaluation Criteria in Solid Tumors) and RECIST 1.1 criteria. BTR was not significantly different between mRECIST and RECIST (p = 0.745). The Non-salvage group had a statistically significant difference in median OS relative to the Salvage group (15.3 vs. 3 months; p < 0.001). Pharmacokinetic analyses demonstrated no correlation of OS with plasma concentration of irinotecan and SN38 (all p > 0.05). Most AEs were Grade 2 (257/279), the most common AE was right upper abdominal pain (180/279). One major AE (tumor rupture) was reported.

CONCLUSION

IRI-HEP-TACE is an alternative treatment for patients with Non-salvage mCRC to the liver.

Evaluation of the safety and efficacy of transarterial sevelamer embolization in a rabbit liver cancer model: A challenge on the size rule for vascular occlusion

As the most efficient method to treat hepatocellular carcinoma in the immediate or advanced stage, transarterial chemoembolization (TACE) is coming into the era of microsphere (MP). Drug-eluting beads have shown their huge potential as an embolic agent and drug carrier for chemoembolization, but their sizes are strictly limited to be above 40 μm, which was considered to occlude vessels in a safe mode. microsphere smaller than 40 µm is easy to be washed out and transported to the normal liver lobe or other organs, causing severe adverse events and failed embolization. To determine whether sevelamer ultrafine particle (0.2-0.5 µm) is qualified as a safe and efficient embolic agent, we investigated the safety and therapeutic efficiency of transarterial sevelamer embolization (TASE) in the VX2 rabbit liver cancer model, aiming to challenge the "40 µm" rule on the selection criteria of the MP. In a four-arm study, blank bead (Callisphere, 100-300 µm), luminescent polystyrene microsphere (10, 100 µm), and sevelamer particle were transarterially administered to evaluate the threshold size of the MP size for intrahepatic or extrahepatic permeability. Another four-arm study was designed to clarify the safety and efficiency of preclinical transarterial sevelamer embolizationTASE tests over other techniques. Sham (saline), TASE, C-TACE, and D-TACE (n = 6) were compared in terms of serum chemistry, histopathology, and tumor necrosis ratio. In the first trials, the "40 µm" rule was detectable on the VX2 cancer model, but the regulation has no application to the new embolic agent as sevelamer ultrafine particles have not been found to leak out from the VX2 lesions, only found in the embolized vessels. Pathology proves that less viable tumor residue was found 2 weeks after the procedure, evidencing a better therapeutic outcome. No adverse events were found except for a short stress response. These results indicate that sevelamer is a safe and efficient embolic as an alternative to the current MP-based embolization therapy techniques.

Limitations and Possibilities of Transarterial Chemotherapeutic Treatment of Hepatocellular Carcinoma

Because diagnostic tools for discriminating between hepatocellular carcinoma (HCC) and advanced cirrhosis are poor, HCC is often detected in a stage where transarterial chemoembolization (TACE) is the best treatment option, even though it provides a poor survival gain. Despite having been used worldwide for several decades, TACE still has many limitations. First, there is a vast heterogeneity in the cellular composition and metabolism of HCCs as well as in the patient population, which renders it difficult to identify patients who would benefit from TACE. Often the delivered drug does not penetrate sufficiently selectively and deeply into the tumour and the drug delivery system is not releasing the drug at an optimal clinical rate. In addition, therapeutic effectiveness is limited by the crosstalk between the tumour cells and components of the cirrhotic tumour microenvironment. To improve this widely used treatment of one of our most common and deadly cancers, we need to better understand the complex interactions between drug delivery, local pharmacology, tumour targeting mechanisms, liver pathophysiology, patient and tumour heterogeneity, and resistance mechanisms. This review provides a novel and important overview of clinical data and discusses the role of the tumour microenvironment and lymphatic system in the cirrhotic liver, its potential response to TACE, and current and possible novel DDSs for locoregional treatment.

Intra-arterial therapy for unresectable colorectal liver metastases: A meta-analysis

PURPOSE

To evaluate the efficacy of hepatic arterial infusion (HAI), conventional trans-arterial chemoembolization (cTACE), drug-eluting embolic trans-arterial chemoembolization (DEE-TACE), trans-arterial radioembolization (TARE) and their combinations with systemic chemotherapy (SCT) for unresectable colorectal liver metastases.

METHODS

A search was conducted on EMBASE, Scopus, PubMed and Web of Science for prospective non-randomized studies and randomized controlled trials (RCTs) from inception to 20^th June 2020. Survival data of patients were recovered from original Kaplan-Meier curves by exploiting a graphical reconstructive algorithm. One-stage meta-analyses were conducted for median overall survival (OS), survival rates (SR), and restricted mean survival time (RMST), while two-stage meta-analyses of proportions were conducted to determine response rates (RR) and conversion-to-resection rates (CRR).

RESULTS

71 prospective non-randomized studies and 21 RCTs were identified comprising 6,695 patients. Among patients treated beyond first line, DEE-TACE+SCT (n=152) had the best survival outcomes of median OS of 26.5 (95%-CI: 22.5-29.1) months and 3-year RMST of 23.6 (95%-CI: 21.8-25.5) months. Upon further stratification by publication year, DEE-TACE+SCT appears to consistently have the highest pooled survival rates at 1-year (81.9%) and 2-years (66.1%) in recent publications (2015-2020). DEE-TACE+SCT and HAI+SCT had the highest pooled-RRs of 56.7% (I²=0.90) and 62.6% (I²=0.87) respectively and pooled-CRRs of 35.5% (I²=0.00) and 30.3% (I²=0.80) respectively.

CONCLUSION

Albeit significant heterogeneity, paucity of high-quality evidence and the non-comparative nature of all analyses, the overall evidence suggests that patients treated with DEE-TACE+SCT may have the best oncological outcomes and greatest potential to be converted for resection.

The short-term safety and efficacy of TANDEM microspheres of various sizes and doxorubicin loading concentrations for hepatocellular carcinoma treatment

Drug-eluting bead transarterial chemoembolization (DEB-TACE) is the most common treatment for unresectable hepatocellular carcinoma (HCC). However, the effect of drug loading concentration and microsphere size on treatment outcomes remains unclear. This retrospective study compares the outcomes of 87 HCC patients who underwent DEB-TACE with half-loaded or full-loaded doxorubicin (maximum capacity 50 mg/mL) in 75-µm or 100-µm microspheres. Treatment with 100-μm microspheres resulted in significantly lower rates of procedure-related complications (6.6% vs. 26.9%; P < 0.05), post-embolization syndrome (32.8% vs. 61.5%, P < 0.05), SIR complications (32.8% vs. 61.5%; P < 0.01) and adverse events involving abdominal pain (19.7% vs. 42.3%; P < 0.05). Half-load doxorubicin microspheres resulted in greater treatment response (OR, 4.00; 95% CI 1.06–15.13; P, 0.041) and shorter hospital stays (OR, − 1.72; 95% CI − 2.77–0.68; P, 0.001) than did microspheres loaded to full capacity. Stratified analysis further showed that patients treated with 100-μm half-load doxorubicin microspheres had a higher CR (63.6% vs 18.0%) and ORR (90.9 vs 54.0%) and a shorter hospital stay (1.6 ± 1.3 vs 4.2 ± 2.3 days) than did those treated with full-load microspheres (P < 0.05). Thus, the drug-loading concentration of microspheres in DEB-TACE should be carefully considered.

The CIREL Cohort: A Prospective Controlled Registry Studying the Real-Life Use of Irinotecan-Loaded Chemoembolisation in Colorectal Cancer Liver Metastases: Interim Analysis

PURPOSE

Transarterial chemoembolisation (TACE) using irinotecan-eluting beads is an additional treatment option for colorectal cancer liver metastases (CRLM) patients that are not eligible for curative treatment approaches. This interim analysis focuses on feasibility of the planned statistical analysis regarding data distribution and completeness, treatment intention, safety and health-related quality of life (HRQOL) of the first 50 patients prospectively enrolled in the CIrse REgistry for LifePearl™ microspheres (CIREL), an observational multicentre study conducted across Europe.

METHODS

In total, 50 patients ≥ 18 years diagnosed with CRLM and decided to be treated with irinotecan-eluting LifePearl™ microspheres TACE (LP-irinotecan TACE) by a multidisciplinary tumour board. There were no further inclusion or exclusion criteria. The primary endpoint is the categorisation of treatment intention, and secondary endpoints presented in this interim analysis are safety, treatment considerations and HRQOL.

RESULTS

LP-irinotecan TACE was conducted in 42% of patients as salvage therapy, 20% as an intensification treatment, 16% as a first-line treatment, 14% a consolidation treatment and 8% combination treatment with ablation with curative intent. Grade 3 and 4 adverse events were reported by 4% of patients during procedure and by 10% within 30 days. While 38% reported a worse, 62% reported a stable or better global health score, and 54% of patients with worse global health score were treated as salvage therapy patients.

CONCLUSION

This interim analysis confirms in a prospective analysis the feasibility of the study, with an acceptable toxicity profile. More patients reported a stable or improved HRQOL than deterioration. Deterioration of HRQOL was seen especially in salvage therapy patients.

TRIAL REGISTRATION

NCT03086096.

Interventional Treatment of Hepatic Metastases from Colorectal Cancer

Modern systemic therapies provide a significant survival benefit in metastatic colorectal cancer. Despite these advances, the durability of response remains limited and nearly all patients progress on systemic treatment. Colorectal liver metastases (CLM) develop in approximately half of patients with metastatic disease and contribute to mortality in most patients. In selected patients, surgical resection of hepatic metastases prolongs survival, indicating the benefits of the targeted treatment of CLM through alternate means. Minimally invasive interventional treatments offer the promise of treating CLM in a wider range of patients than those eligible for surgical resection. Thermal ablation and intra-arterial therapies, including chemoembolization and radioembolization, are commonly used in the treatment of CLM. Each of these treatment modalities will be discussed in detail with an emphasis on the available clinical data for each interventional treatment for CLM.

Nanosized drug-eluting bead for transcatheter arterial chemoembolization (ND-TACE)

Dextran-coated arsenite nanoparticles benefit interventional therapy by occluding tumor feeding vessels and sustainable release of arsenic trioxide.