New Perspectives in the Treatment of Colorectal Metastases

Abstract

Background: In recent years, the management of metastatic colorectal cancer has become more aggressive and more multidisciplinary. New treatment options have been proposed in addition to the standard approach of resection of liver metastases and chemotherapy.

Summary: Selected patients with synchronous limited peritoneal and liver disease (peritoneal cancer index <12 and <3 liver metastases) can be scheduled for aggressive treatment, including cytoreductive surgery, hyperthermic intraperitoneal chemotherapy, and liver resection. This approach has achieved survival benefits, even if the treatment is unlikely to be curative in most patients. Moreover, liver transplantation has been recently reconsidered for liver-only metastases, resulting in the de facto reinstatement of the chance of surgery for some unresectable patients. Even though indications for liver transplantation remain to be standardized, preliminary studies have reported extremely promising outcomes. Radio-embolization has proven to be an effective additional tool for the treatment of unresectable tumors, and its potential role in association with chemotherapy for resectable disease is currently being investigated. Stereotactic body radiation therapy is a safe, non-invasive, and effective therapeutic option for patients with inoperable oligometastatic disease. Thanks to recent technical progress, high radiation doses can now be delivered in fewer fractions with excellent local disease control and a low risk of radiation-induced liver injury. Finally, radiofrequency ablation (RFA) for colorectal metastases has become more effective, with results approaching those of surgical series. New interstitial treatments, such as microwave ablation and irreversible electroporation, could overcome some of the limitations of RFA, thereby further expanding indications and optimizing outcomes.

Key messages: Currently, a multidisciplinary approach to patients with colorectal liver metastases is mandatory. Aggressive surgical treatments should be integrated with all the available non-surgical options to maximize disease control and patient survival.

Keywords: Colorectal liver metastases and peritoneal carcinomatosis; Liver transplantation; Radioembolization; Radiofrequency ablation and microwave ablation; Stereotactic body radiation therapy.

Fig. 1

Overall survival according to number of CLM and the PCI after surgical treatment with curative intent.

Fig. 2

Super-selective intra-arterial delivery of Y90 Sir-Spheres was performed in a 68-year-old woman with two liver metastases. Approximately 2 years later, computed tomography (CT) showed that the two lesions had virtually disappeared.

Fig. 3

Patient treated with SBRT for inoperable CLM. aPre-treatment positron emission tomography (PET) image showing the lesions. bVisualization of dose distribution on the planning target volume. cPET-CT image at 6 months after SBRT showing complete metabolic response.