Adjunctive radiofrequency ablation of metastatic neuroendocrine cancer to the liver complements surgical resection

Background: Resection of liver metastases from neuroendocrine cancer (NEC) prolongs survival and provides durable symptom relief. Not all hepatic lesions are amenable to resection, particularly when there is multifocal involvement. In this study, it was hypothesized that ablation of concomitant non-resectable NEC liver metastases is safe and salvages patients who would not have been selected for cytoreductive surgery. Methods: Patients who underwent adjuvant ablation of NEC liver metastases between 1995 and 2008 were reviewed. NEC was classified by patient and tumour characteristics. Regression and KaplanMeier models were used to compare variables and generate survival curves. Results: Ninety-four patients underwent hepatic resection and intra-operative ablation of metastatic NEC. The median number of lesions ablated was 3, and median size was 1.4cm. One abscess occurred at an ablation site. Local recurrence was detected in four patients (3.8%). Overall survival was 80% and 59% at 5 and 10 years. Age, gender, tumour type, grade, primary site and need for repeat ablation had no significant association with survival. The Ki67 proliferative index was a significant predictor of decreased survival. Symptom-free survival was 34% at 3 years and 16% at 5 years, independent of the tumour grade. Conclusion: Concurrent ablation of NEC metastases to the liver not amenable to resection is safe and increases the candidacy of patients for cytoreductive surgery. Ablation performed intra-operatively and repeated post-operatively as needed provides significant symptom control regardless of the tumour grade.