Background: Many neuroendocrine tumors (NETs) have a tendency to metastasize to the liver. In case of limited number of metastases, liver surgery or radiofrequency ablation (RFA) may result in apparently total clearance of metastases. However, it is not clear whether such therapy will provide symptom reduction or increased survival.
Methods: Seventy-three patients with foregut (n=6) or midgut carcinoids (n=37) or endocrine pancreatic tumors (n=28), and two patients with NETs without discernable origin were studied. Symptoms were evaluated using a Symptom Severity Score. Liver surgery was performed in 42 operations and RFA on 205 lesions.
Results: Apparently total clearance of liver metastases was attained in 1 of 6 patients with foregut carcinoids, 15 of 37 with midgut carcinoids, and 13 of 28 with EPT. Symptom improvement was noted in 12 of 17 (70.6%) patients with carcinoid syndrome, and 75% also reduced their 5-HIAA and P-CgA by at least 50%. Patients with nonfunctioning EPT generally had no improvement of symptoms after surgical/RFA liver treatment, but eight patients had functioning EPT, and four of these reduced their biochemical markers by at least 50%. NETs with higher Ki67 index tended to recur more often. Complications occurred in 9 of 45 open surgery procedures, and in 8 of 203 RFA procedures.
Conclusions: Treatment of liver metastases is successful in midgut carcinoid patients with limited liver metastases. Patients with foregut carcinoid and EPTs recur more often, possibly related to higher Ki67 index, and treatment of liver lesions less often reduces symptoms. Liver resections and RFA may be safely performed, and RFA is associated with few complications.