Surgical resection of neuroendocrine tumor liver metastases as part of multimodal treatment strategies: A propensity score matching analysis.

BACKGROUND

It remains unclear whether liver resection as part of multimodal therapy of neuroendocrine liver metastases (NELM) is superior to non-surgical (interventional and medication-based) treatment alone. This study should determine if patients with NELM undergoing hepatic surgery in addition to non-surgical treatment have improved overall survival compared to patients undergoing non-surgical therapy alone.

METHODS

123 patients undergoing treatment of NELM between 1995 and 2014 were included in this retrospective cohort study. Two groups were formed: (A) surgery and non-surgical therapy and (B) non-surgical treatment alone. To minimize the bias of patient selection propensity score matching was used.

RESULTS

There was significantly better overall survival for group A (152 months, 95%CI: 119-185) compared to group B (63 months, 95%CI: 45-81) measured from the initial diagnosis of the metastases (P = 0.003). After propensity score matching, 37 patients undergoing surgical resection of NELM within a multimodal treatment were compared to 37 patients undergoing non-surgical treatment. Under these circumstances, surgery had no significant influence on survival (group A: 134 months, 95% CI: 94-173; group B: 76 months, 95% CI: 53-99, P = 0.23). Based on a multivariate Cox proportional hazard model, only Ki-67 of primary tumor >20% (HR, 50.776; 95%CI, 4.056-635.71; P = 0.002) and no resection of primary tumor (HR, 10.464; 95%CI, 1.873-58.448; P = 0.007) remained independent risk factors.

CONCLUSION

After minimizing patient selection bias, patients with hepatic resection as integral of multimodal therapy of NELM do not have better overall survival than those receiving non-surgical treatment alone.