Systematic review of resection of primary midgut carcinoid tumour in patients with unresectable liver metastases.

Surgery for small intestinal neuroendocrine tumours (SI-NETs) is limited by metastatic disease in most patients. However, resection of the primary lesion alone has been advocated in patients with unresectable liver metastases. The present systematic review investigated the value of surgical resection of the primary lesion in patients with unresectable metastatic disease.MEDLINE was searched for studies reporting the outcome of patients with SI-NETs and unresectable liver metastases where there was an explicit comparison between resection of the primary lesion alone and no resection. The primary outcome was overall survival. Secondary outcomes were progression-free survival, treatment-related mortality and relief of symptoms.Meta-analysis was not possible, but six studies were analysed qualitatively to highlight useful information. Possible confounders in these studies were the inclusion of patients with other primary tumour sites, unknown primary tumour or non-metastatic disease. Bearing in mind these limitations, there was a clear trend towards longer survival in patients who underwent surgical resection in all studies; their median overall survival ranged from 75 to 139 months compared with 50-88 months in patients who did not have resection. The difference between the two groups was statistically significant in three studies. Data on symptomatic improvement were scarce and did not suggest a clear benefit of surgery. Surgery-related mortality seemed low.Available data suggest a possible benefit of resection of the primary lesion in patients with unresectable liver metastases, but the studies have several limitations and the results should therefore be considered with caution.