Electrocoagulation for liver metastases.

Abstract

Primary liver tumours and liver metastases from colorectal carcinoma are two of the most common malignant tumours to affect the liver. The liver is second only to the lymph nodes as the most common site for metastatic disease. More than half of the people with metastatic liver disease will die from metastatic complications. Electrocoagulation by diathermy is a method used to destroy tumour tissue, using a high-frequency electriccurrent generating high temperatures, applied locally with an electrode (needle, blade, or ball). The objective of this method is to destroy the tumour completely, if possible, in a single session. With the time, electrocoagulation by diathermy has been replaced by other techniques, but the evidence is unclear. To assess the beneficial and harmful effects of electrocoagulation by diathermy, administered alone or with another intervention,versus no intervention, other ablation methods, or systemic treatments in people with liver metastases. We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, LILACS, Science Citation Index Expanded, Conference Proceedings Citation Index - Science, CINAHL,ClinicalTrials.gov, ICTRP, and FDA to October 2020. We consideredall randomised trials that assessed beneficial and harmful effects of electrocoagulation by diathermy, administered alone or with another intervention, versus comparators, in people with liver metastases, regardless of the location of the primary tumour. We used standard methodological procedures expected by Cochrane. We assessed risk of bias of the included trialusing predefined risk of bias domains, and presented the review results incorporating the certainty of the evidence using GRADE. We included one randomised clinical trial with 306 participants (175 males;131 females) who had undergone resection of the sigmoid colon, and who had five or more visible andpalpable hepatic metastases. The diagnosis was confirmed by histological assessment (biopsy) and by carcinoembryonic antigen (CEA) level. The trial was conducted in Iraq. The age of participants ranged between 38 and 79 years. The participants wererandomised to four different study groups. The liver metastases were biopsied and treated (only once) in three of the groups: 75 received electrocoagulation by diathermy alone, 76 received electrocoagulation plus allopurinol, 78 received electrocoagulation plus dimethyl sulphoxide. In the fourth intervention group, 77 participants functioning as controls received a vehicle solution of allopurinol 5 mL 4 x a dayby mouth; the metastases were left untouched. The status of theliver and lungs wasfollowed by ultrasound investigations, without the use of a contrast agent. Participants were followed for five years. The analyses are based on per-protocol data only analysing 223 participants. We judged the trial to be at high risk of bias.After excluding 'nonevaluable patients', the groups seemed comparable for baseline characteristics. Mortality due to disease spread at five-yearfollow-up was98% in the electrocoagulation group (57/58 evaluable people); 87% in the electrocoagulation plus allopurinol group (46/53 evaluable people); 86% in the electrocoagulation plus dimethyl sulphoxide group (49/57 evaluable people); and 100% in the control group (55/55 evaluable people). We observedno difference in mortality between the electrocoagulation alone group versus the control group (risk ratio (RR) 0.98, 95%confidence interval (CI) 0.94 to 1.03; 113 participants; very low-certaintyevidence). We observedlower mortality in the electrocoagulation combined with allopurinol or dimethyl sulphoxide group versus the control group (RR0.87, 95% CI0.80 to 0.95; 165 participants; low-certainty evidence). We are very uncertainregarding post-operative deaths betweenthe electrocoagulation alone group versusthe control group(RR1.03, 95% CI 0.07 to 16.12; 152 participants; very low-certainty evidence)andbetween the electrocoagulation combined with allopurinol or dimethyl sulphoxidegroups versusthe control group(RR1.00, 95%CI0.09 to 10.86; 231 participants; very low-certainty evidence). The trial authors did not report data on number of participants with other adverse events and complications, recurrence of liver metastases, time to progression of liver metastases, tumour response measures, and health-related quality of life.Data on failure to clear liver metastaseswere not provided for the control group. There was no information on funding or conflict of interest. We identified no ongoing trials. The evidence on the beneficial and harmful effects of electrocoagulation alone or in combination with allopurinol or dimethyl sulphoxide in people with liver metastases is insufficient, as it is based on one randomised clinical trial at low to very low certainty. It is very uncertain if there is a difference in all-cause mortality and post-operative mortality between electrocoagulation alone versus control. It is also uncertain if electrocoagulation in combination with allopurinol ordimethyl sulphoxidemay result in a slight reduction of all-cause mortality in comparison with a vehicle solution of allopurinol (control).It is very uncertain if there is a difference in post-operative mortality between the electrocoagulation combined with allopurinol or dimethyl sulphoxidegroup versuscontrol.Data on other adverse events and complications, failure to clear liver metastases or recurrence of liver metastases, time to progression of liver metastases, tumour response measures, and health-related quality of life were most lacking or insufficiently reported for analysis. Electrocoagulation by diathermy is no longer used in the described way, and this may explain the lack of further trials.