Isolated Hepatic Perfusion for the Treatment of Liver Metastases

Poor Response to Checkpoint Immunotherapy in Uveal Melanoma Highlights the Persistent Need for Innovative Regional Therapy Approaches to Manage Liver Metastases

Uveal melanoma is a cancer that develops from melanocytes in the posterior uveal tract. Metastatic uveal melanoma is an extremely rare disease that has a poor long-term prognosis, limited treatment options and a strong predilection for liver metastasis. Median overall survival has been reported to be 6 months and 1 year mortality of 80%. Traditional chemotherapy used in cutaneous melanoma is ineffective in uveal cases. Surgical resection and ablation is the preferred therapy for liver metastasis but is often not feasible due to extent of disease. In this review, we will explore treatment options for liver metastases from uveal melanoma, with a focus on isolated hepatic perfusion (IHP). IHP offers an aggressive regional therapy approach that can be used in bulky unresectable disease and allows high-dose chemotherapy with melphalan to be delivered directly to the liver without systemic effects. Long-term median overall survival has been reported to be as high as 27 months. We will also highlight the poor responses associated with checkpoint inhibitors, including an overview of the biological rationale driving this lack of immunotherapy effect for this disease. The persistent failure of traditional treatments and immunotherapy suggest an ongoing need for regional surgical approaches such as IHP in this disease.

Treatment of Metastatic Uveal Melanoma: Systematic Review

INTRODUCTION

More than 50% of patients with uveal melanoma end up developing metastases. Currently, there is no standard first-line treatment that facilitates proper management of the metastatic disease.

METHODS

A systematic review of the last 40 years in PubMed with an exhaustive and strict selection of studies was conducted, in which the unit of measurement was overall survival (OS) expressed in Kaplan-Meier curves or numerically.

RESULTS

After the selection process, 110 articles were included. Regional therapies, such as intra-arterial liver chemotherapy (OS: 2, 9-22 months), isolated liver perfusion (OS: 9, 6-27, 4 months), or selective internal radiation therapy (OS: 18 months in monotherapy and 26 months in combination with other therapies) showed some superiority when compared to systemic therapies, such as chemotherapy (OS: 4, 6-17 months), immunotherapy (OS: 5-19, 1 month), immunosuppression (OS: 11 months), or targeted therapy (OS: 6-12 months), without being significant.

CONCLUSIONS

The results of this review suggest that there are no important differences in OS when comparing the different current treatment modalities. Most of the differences found seem to be explained by the heterogenicity of the different studies and the presence of biases in their design, rather than actual extensions of patient survival.

Hepatic metastasis from colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers in the world. About two third of patients with CRC will develop distant recurrence at some point in time. Liver is the most common site where distant metastasis takes place. While the overall survival (OS) of patients with metastatic CRC was poor about 3 decades ago, there has been tremendous improvement in this area in the recent years. With the advent of effective systemic chemotherapy and biologic agents and better understanding of the biological behaviour of the tumour, aggressive treatment strategies such as metastatectomy of the liver metastases (or lung metastases) are now acceptable. More importantly, it has transformed the way how stage IV CRCs are being managed. From predominantly palliative as the primary aim, a comprehensive multidisciplinary approach is now the mainstay of treatment with very successful outcomes. Combination of systemic therapies with liver resection has been shown to be effective in providing promising survival benefits. In addition, other adjunctive modalities in targeting the liver metastases such as ablation, combining resection and ablation, transarterial chemoembolization, stereotactic body radiotherapy (SBRT), hepatic artery perfusion, etc. have also been demonstrated variable outcome in treating colorectal liver metastasis (CRLM). Very recently, transplant oncologists have also explored using liver transplantation as a treatment modality for unresectable CRLM, which has demonstrated very good long-term survival in well selected cases. The new paradigm in the treatment of metastatic CRC has dawned.

Hepatic artery infusion of melphalan in patients with liver metastases from ocular melanoma

BACKGROUND AND OBJECTIVES

Ocular melanoma has a predilection for liver metastases. Systemic treatment is ineffective and the optimal regional therapy approach is poorly defined. Isolated hepatic perfusion (IHP) with melphalan has emerged as a viable treatment option, however a subset of patients are not candidates for this treatment. We therefore sought to determine if melphalan could be safely administered via the hepatic artery for these patients.

METHODS

A retrospective review of patients treated with hepatic artery infusion (HAI) of melphalan was undertaken. All patients had contraindications to IHP and were without other therapy options. Melphalan infusion was repeated every four weeks with consideration for dose escalation in the absence of toxicity or significant disease progression.

RESULTS

Fourteen patients were treated with HAI of melphalan from 2010 to 2015. All patients had hepatic dysfunction or prohibitive tumor volume precluding IHP. There were no procedure-related complications. Three patients (21%) died within 30 days and the median survival was 2.9 months. Elevated baseline bilirubin > 2.5 mg/dL was associated with worse overall survival (0.93 vs 6.3 months, P < 0.05).

CONCLUSION

HAI of melphalan is safe and feasible for patients with metastatic ocular melanoma. Further study to determine the optimal utilization of this treatment approach is warranted.

Recurrence after microwave ablation of liver malignancies: a single institution experience

BACKGROUND

Microwave ablation (MWA) is increasingly used to achieve local control for liver tumours. This study sought to examine a monocentric experience with MWA, with a primary hypothesis that primary tumour histology was a significant predictor of early recurrence.

METHODS

Retrospective single-institution review identified consecutive patients with liver tumours treated by MWA. Cox proportional hazards models assessed significance of prognostic variables.

RESULTS

Seventy-two patients (43 female, 60%) underwent 83 MWA procedures for 157 tumours. Tumour histologies included hepatocellular cancer (10 operations), colorectal metastases (39), metastatic carcinoid (20) and other (14). The median tumour size was 2.0 cm. A concomitant liver resection was performed in 50 cases (60%). Crude peri-operative morbidity and mortality rates were 16% and 1%, respectively. The median follow-up was 16 months. Ablations were complete for 149 out of 157 tumours (95%). The median overall and recurrence-free survivals were 36 and 18 months, respectively. There was no difference in time to recurrence between the primary tumour types. In multivariable models, recurrence-free survival was independently associated with the use of neoadjuvant [hazard ratio (HR): 2.90, 95% confidence interval (CI): 1.09-7.76, P = 0.034] and adjuvant chemotherapy (HR: 0.36, 95% CI: 0.15-0.82, P = 0.016).

CONCLUSIONS

MWA is a safe and feasible approach for local control of liver tumours. While chemotherapy administration was associated with time to recurrence after MWA, larger studies are needed to corroborate these findings.