A nationwide multicenter study was performed to examine short- and long-term effects of irreversible electroporation (IRE) for hepatocellular carcinoma (HCC) and colorectal cancer liver metastases (CRCLM). IRE is an alternative method when thermal ablation is contraindicated because of risk for serious thermal complications. All consecutive patients in Sweden treated with IRE because of HCC or CRCLM, were included between 2011 and 2018. We evaluated medical records and radiological imaging to obtain information regarding patient-, tumor-, and treatment characteristics. We also assessed local tumor progression, and survival. In total 206 tumors in 149 patients were treated with IRE. Eighty-seven patients (58.4%) had colorectal cancer liver metastases, and 62 patients (41.6%) had hepatocellular carcinoma. Median tumor size was 20 mm (i.q.r. 14-26 mm). Median overall survival for CRCLM and HCC, were 27.0 months (95% CI 22.2-31.8 months), and 35.0 months (95% CI 13.8-56.2 months), respectively. Median follow-up time was 58 months (95% CI 50.6-65.4). Local ablation success at six and twelve months for HCC was 58.3% and 40.3%, and for CRCLM 37.7% and 25.4%. The median time to local tumor progression (LTP) for HCC was 21.0 months (95% CI: 9.5-32.5 months), and for CRCLM 6.0 months (95% CI: 4.5-7.5 months). At 30-day follow-up, 15.4% (n = 23) of patients suffered from a complication rated as Clavien-Dindo grade 1-3a. Three patients (2.0%) had grade 3b-5 with one death in a thromboembolic event. IRE is a safe ablation modality for patients with liver tumors that are located in such a way that other treatment options are unsuitable.

The optimal treatment strategy for patients with synchronous colorectal liver metastases (CRLM) is unclear. The aim of this study was to compare the outcome of the simultaneous, liver-first, and colorectal-first surgical approaches. All consecutive patients who had been resected with curative intent for CRLM were included. A Cox regression model was constructed, and an intention-to-treat analysis was performed between the liver-first and the simultaneous approaches, after propensity score matching. 658 patients were included in the analysis. 92 patients had a simultaneous resection, 163 patients had liver-first, and 403 patients had a colorectal-first approach. Overall survival was 54.9 months (95% CI 39.2-70.4) in the liver-first group, 54.5 months (95% CI 46.8-62.3) in colorectal-first group, and 59.6 months (95% CI 42.2-77.0) in the simultaneous group (log-rank p =0.850). In the matched cohort there were no differences in Clavien-Dindo 3a (p = 0.992) or 3b and greater (p = 0.999). Median overall survival was for liver-first group 42.2 months (95% CI 26.3-58.2), and for the simultaneous group 56.2 months (95% CI 47.1-65.4) (stratified log-rank p = 0.455). A simultaneous approach was not associated with worse overall survival or morbidity compared to a liver-first approach.

Background: Long-term survival for selected patients with peritoneal metastases (PM) from colorectal cancer (CRC) is possible when treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The objective of this study was to compare three different oxaliplatin-based (OX)-HIPEC regimens. Primary end-point was disease-free survival (DFS), and secondary endpoints, morbidity and overall survival (OS). Methods: This is a retrospective study of all patients with colorectal PM treated with CRS and HIPEC between 2004 and 2015 from the prospectively maintained Uppsala HIPEC database. One hundred and thirty-three patients were identified. Three HIPEC regimens were included: OX-HIPEC, OX-HIPEC + post-operative intraperitoneal chemotherapy (EPIC) with 5-fluorouracil (5-FU), and oxaliplatin-irinotecan-based (OXIRI)-HIPEC. Multivariable Cox regression for DFS was performed. Results: Sixty-one patients received OX-HIPEC, 24 patients received OX-HIPEC + 5-FU EPIC, and 48 patients received OXIRI-HIPEC. The DFS for the OX-HIPEC group was 10.5 months, OX-HIPEC + EPIC 11.9 months, and OXIRI-HIPEC 13.4 months (OX-HIPEC vs. OXIRI HIPEC, P=0.049). The morbidity and OS did not differ between the groups. In the multivariable analysis, low peritoneal cancer index (PCI), absence of liver metastases, low completeness of cytoreduction (CC) score, and multiple drug (EPIC or OXIRI) HIPEC regimen were independent prognostic factors for DFS. Conclusions: This study showed improved DFS with an intensification of HIPEC by adding irinotecan or EPIC compared to oxaliplatin alone without an increase in morbidity or mortality.

Several existing scoring systems predict survival of patients with colorectal liver metastases. Many lack validation, rely on old clinical data, and have been found to be less accurate since the introduction of chemotherapy. This study aimed to construct and validate a clinically relevant preoperative prognostic model for patients with colorectal liver metastases. A predictive model with data available before surgery was developed. Survival was analysed by Cox regression analysis, and the quality of the model was assessed using discrimination and calibration. The model was validated using multifold cross-validation. The model included 1212 consecutive patients who underwent liver resection for colorectal liver metastases between 2005 and 2015. Prognostic factors for survival included advanced age, raised C-reactive protein level, hypoalbuminaemia, extended liver resection, larger number of metastases, and midgut origin of the primary tumour. A Composite Score was developed based on the prognostic variables. Patients were classified into those at low, medium, and high risk. Survival differences between the groups were significant; median overall survival was 87.4 months in the low-risk group, 50.1 months in the medium-risk group, and 22.6 months in the high-risk group. The discriminative performance, assessed by the concordance index, was 0.71, 0.67, and 0.67 respectively at 1, 3, and 5 years. Calibration, assessed graphically, was close to perfect. A multifold cross-validation of the model confirmed its internal validity (C-index 0.63 versus 0.62). The Composite Score categorizes patients into risk strata, and may help identify patients who have a poor prognosis, for whom surgery is questionable.

Chemotherapy is widely used as an adjunct to surgery in the treatment of patients with resectable colorectal liver metastases. The aim of this study was to examine whether chemotherapy confers a survival benefit in patients with a solitary colorectal liver metastasis. All consecutive patients between 2009 and 2017 in Sweden who were resected for a solitary colorectal liver metastasis were included. Patients treated with chemotherapy were compared with patients who had surgery alone. Unmatched and propensity score matched analyses were performed to compare overall survival, morbidity and mortality. Of 1224 eligible patients, 641 (52.4%) patients had chemotherapy, and 583 (47.6%) had surgery alone. After propensity score matching, two balanced groups with 102 patients in each, were analyzed. There was no difference in readmission within 30-days (p = 0.250), or morbidity, defined as Clavien-Dindo 3a or greater, between the groups (p = 0.761). There were no mortalities within ninety days. Radical resection margins were achieved in 92 (n = 94) per cent in the chemotherapy group, and 77 (n = 78) per cent in the surgery alone group (p = 0.016). Median overall survival was 91 (95% CI 73-109) months in the chemotherapy group, and 78 (95% CI 37-119) months in the surgery-alone group (p = 0.652). This nationwide register-based study showed no difference in overall survival between patients treated with chemotherapy compared to surgery alone. Upfront surgery may be advisable in resectable solitary colorectal liver metastasis.