Long‐term outcomes following microwave ablation for liver malignancies. BJS 2015; 102: 85-91.

Results

A total of 176 patients with 416 tumours were analysed. Colorectal liver metastases (CRLM) comprised 81·0 per cent of tumours, hepatocellular carcinoma 8·4 per cent, primary biliary cancer 1·7 per cent and non‐CRLM 8·9 per cent. Median follow‐up was 20·5 months. Local recurrence developed after treatment of 33 tumours (7·9 per cent) in 31 patients (17·6 per cent). Recurrence rates increased with tumour size, and were 1·0, 9·3 and 33 per cent for lesions smaller than 1 cm, 1–3 cm and larger than 3 cm respectively. On univariable analysis, the local recurrence rate was higher after ablation of larger tumours (hazard ratio (HR) 2·05 per cm; P < 0·001), in those with a perivascular (HR 3·71; P = 0·001) or subcapsular (HR 2·71; P = 0·008) location, or biliary or non‐CRLM histology (HR 2·47; P = 0·036), and with use of the 2·4‐GHz ablation system (HR 3·79; P = 0·001). Tumour size (P < 0·001) and perivascular position (P = 0·045) remained significant independent predictors on multivariable analysis. Regional chemotherapy was associated with decreased local recurrence (HR 0·49; P = 0·049). Overall survival at 4 years was 58·3 per cent for CRLM and 79·4 per cent for other pathology (P = 0·360).