Abstracts Category : Other

Liver metastases from colorectal cancer

by Jennie Engstrand

Introduction: Colorectal cancer (CRC) is the third most common cancer worldwide. At diagnosis of CRC 20-25% of patients have metastatic disease. The liver is the most common metastatic site and liver metastases are detected in 25-30% of all patients. A quarter of these patients are amenable for liver resection that results in a five-year survival exceeding 50%. The indications for liver resection continue to broaden and are no longer limited by number and size of liver metastases nor the presence of extrahepatic metastases. Currently liver resection is indicated when macroscopic tumour clearance can be achieved with preservation of a sufficient future liver remnant. Different strategies to improve resectability exist such as portal vein occlusion, two-stage resections, associating liver partition and portal vein ligation for staged hepatectomy and thermal ablation, mainly radiofrequency ablation or microwave ablation (MWA). Decisions on management of patients with metastatic CRC should ideally be made in a multidisciplinary team (MDT) setting. Failing to do so may result in suboptimal management and patients that could be resected are not necessarily offered curative-intended treatment. As a result of this there are known regional differences in the treatment of patients with liver metastases that may affect survival. For patients not suitable for resection, either due to the metastatic burden or comorbidity omitting extensive surgery, local ablation is an option. Aims: The aim of Study I was to provide detailed population-based data of liver metastatic patterns, treatment and survival in patients with metastatic CRC. In Study II, the potentially improved resection rates were evaluated in a scenario where all patients with liver metastatic disease, irrespective of extrahepatic metastases, were assessed by a liver MDT. Study III aimed to describe the feasibility and safety of a multiple MWA strategy in patients with initially unresectable liver metastases. The primary aim of Study IV was to evaluate the accuracy and safety of antenna placement in stereotactic computed tomography-guided MWA of primary and secondary liver tumours. The secondary aims of Study IV were to evaluate the feasibility of the navigation system, to measure the procedure-related radiation dose and to assess the safety of high-frequency jet ventilation for target motion control. Patients and Methods: In Studies I and II, a population-based cohort consisting of all patients diagnosed with CRC in the Stockholm and Gotland region during 2008, identified from the Swedish Colorectal Cancer Registry, was used. Details of metastatic spread, referral to a MDT conference and oncologic and surgical treatment were retrieved from electronic patient charts and recorded during a five-year follow-up period or until death. Predictors of survival in Studies I and III were estimated using a Cox proportional hazards model. Survival curves were illustrated using Kaplan-Meier estimates and survival functions were compared using the log-rank test