Multi-institutional Development and External Validation of a Nomogram Predicting Recurrence After Curative Liver Resection for Neuroendocrine Liver Metastasis.

OBJECTIVES: To establish and externally validate a novel nomogram to predict recurrence of patients undergoing curative liver resection for neuroendocrine liver metastasis (NELM). METHODS: A total of 279 patients who underwent curative liver resection for NELM identified from an international multicenter database were utilized to develop a nomogram to predict recurrence; 98 cases from two different institutions were used to externally validate the nomogram. RESULTS: Among 279 patients in the development cohort, median age was 57 years, and 50.5% were male. On multivariate analysis, primary tumor location (pancreatic vs nonpancreatic, HR 2.1, p = 0.004), tumor grade (Ref. well, moderate HR 1.9, p = 0.022; poor HR 1.6, p = 0.238), lymph node metastasis (positive vs negative, HR 2.6, p = 0.002), and extent of resection (major vs parenchymal-sparing resection, HR 0.3, p = 0.001) were independently associated with recurrence-free survival. The beta coefficients from the final multivariable model were utilized to develop a nomogram. The nomogram demonstrated good ability to predict risk of recurrence (training cohort, C-index 0.754; validation cohort, C-index 0.748). The calibrated nomogram predicted recurrence-free survival that closely corresponded to actual recurrence. Decision curve analysis demonstrated that the nomogram had a good net benefit for most of the threshold probabilities, especially between 20 and 60%, in both development and validation cohorts. CONCLUSIONS: The externally validated novel nomogram predicted 3- and 5-year recurrence-free survival among patients with NELM. Prediction of individual recurrence risk may help guide personalized estimates of prognosis, as well as surveillance protocols and consideration of adjuvant therapies.

Hepatic Resection for Non-functional Neuroendocrine Liver Metastasis: Does the Presence of Unresected Primary Tumor or Extrahepatic Metastatic Disease Matter?

OBJECTIVES: The objective of this study was to assess the impact of unresected primary tumor, as well as extrahepatic metastasis, on the long-term prognosis of patients undergoing hepatic resection for non-functional neuroendocrine liver metastasis (NF-NELM). METHODS: Patients who underwent hepatic resection for NF-NELM were identified from a multi-institutional database. Data on clinical and pathological details, as well as the long-term overall survival (OS) were obtained and compared. Propensity score matching was performed to generate matched pairs of patients. RESULTS: Among the 332 patients with NF-NELM, 281 (84.6%) underwent primary tumor resection, while 51 (15.4%) did not. Patients who underwent primary resection were more likely to have a pancreatic primary and metachronous NELM. The long-term OS of patients who did and did not have the primary neuroendocrine tumor (NET) resected was comparable on both unmatched (10-year survival rate 66.8% vs. 54.0%, p = 0.192) and matched (10-year survival rate 75.7% vs. 60.4%, p = 0.271) analyses. In contrast, patients with NF-NELM and extrahepatic metastasis had a worse OS following resection compared with patients who had intrahepatic-only metastasis on unmatched (10-year survival rate 37.5% vs. 69.3%, p = 0.002) and matched (10-year survival rate 37.5% vs. 86.3%, p = 0.011) analyses. On multivariable analysis, while resection of the primary NET was not associated with OS (hazard ratio [HR] 0.7, 95% confidence interval [CI] 0.4-1.2, p = 0.195), the presence of extrahepatic metastasis was independently associated with long-term risk of death (HR 3.9, 95% CI 1.7-9.2, p = 0.002). CONCLUSIONS: While surgery should be considered for patients with NF-NELM who have an unresectable primary tumor, operative resection of NF-NELM may not be as beneficial in patients with extrahepatic disease.

Early recurrence of well-differentiated (G1) neuroendocrine liver metastasis after curative-intent surgery: Risk factors and outcome.

BACKGROUND: The objective of the current study was to identify the risk of early vs late recurrence of well-differentiated (G1) neuroendocrine liver metastasis (NELM) after curative-intent resection. METHODS: Patients who underwent curative-intent resection for well-differentiated NELM were identified from a multi-institutional database. Clinicopathological details, as well as the long-term overall (OS) and recurrence free survival (RFS) were obtained and compared. The optimal cutoff value to differentiate early and late recurrence was determined to be 1 year based on trend curve analysis. RESULTS: Among the 548 patients undergoing curative resection for NELM, 162 patients had a well-differentiated NELM. After a median follow-up of 69 months, 59 (36.4%) patients had tumor recurrence; 23 (39.0%) patients recurred within 1 year (early recurrence) after surgery, while 36 (61.0%) recurred after 1 year (late recurrence). Early recurrence was associated with worse outcome vs late recurrence (5-year OS, 72.4% vs 92.0%; P = 0.020) and no recurrence (5-year OS, 72.4% vs 100.0%; P < 0.001). In addition, postrecurrence survival was worse within 36 months after recurrence among patients who recurred early compared with patients who recurred late (survival after recurrence at 36 months: early recurrence, 71.6% vs late recurrence, 91.4%; P = 0.047), although survival was comparable at 60 months (early recurrence, 71.6% vs late recurrence, 70.0%; P = 0.304). On multivariable analysis, nonfunctional neuroendocrine tumors (hazard ratio [HR], 4.4; 95% confidence interval [CI], 1.2-16.7; P = 0.029) and lymph node metastasis (HR, 3.6; 95% CI, 1.1-11.1; P = 0.028) were independent risk factors for early recurrence, whereas lymph node metastasis (HR, 3.0; 95% CI, 1.2-7.8; P = 0.020) and R1 resection (HR, 3.9; 95% CI, 1.4-10.5; P = 0.008) were independently associated with late recurrence. CONCLUSIONS: Roughly, one-third of patients with well-differentiated NELM experienced a recurrence following curative-intent surgery. Among patients who recurred, two out of five patients recurred within 1 year after surgery. Early recurrence of well-differentiated NELM was associated with the hormone functional status and lymph node metastasis.

Management and outcomes of patients with recurrent neuroendocrine liver metastasis after curative surgery: An international multi-institutional analysis.

OBJECTIVE: We sought to characterize the treatment, as well as define the long-term outcomes, of patients with recurrent neuroendocrine liver metastasis (NELM). METHODS: Between 1990 and 2014, 322 patients undergoing curative intent liver surgery for NELM were identified from a multi-institutional database. Recurrences were classified as intrahepatic, extrahepatic, and both intra- and extra-hepatic. RESULTS: Overall, median, 1-, 5-, 10-year DFS were 3.1 years, 75.5%, 40.4%, and 32.1%, respectively. After curative intent liver surgery, 209 patients (64.9%) recurred within a median follow-up of 4.5 years, while 113 (35.1%) patients were alive without disease with a follow-up time ≥3 years. The site of recurrence was intrahepatic only (n = 111, 65.7%), extrahepatic only (n = 19, 11.2%), or intra- and extra-hepatic (n = 39, 23.1%). Compared with intrahepatic only recurrence, extrahepatic only, and combined intra- and extra-hepatic recurrence were associated with a worse long-term outcome (10-year OS: intrahepatic only, 42.5%, 95%CI, 24.9-59.0 vs extrahepatic only, 0% and combined intra- and extra-hepatic, 21.5%, 95%CI, 5.3-44.0) (P < 0.001). Most patients were treated with repeat surgery (n = 49, 36.6%), while 34 (23.5%) patients received a somatostatin analogue, 27 (18.6%) systemic cytotoxic chemotherapy, and 27 (21.4%) patients had intra-arterial therapy. Ten-year OS among patients who underwent repeat surgery or intra-arterial treatments was 60.3% (95%CI, 34.1-78.8) and 52.0% (95%CI, 30.6-69.9), respectively. Patients who received somatostatin analogues (45.9% 95%CI, 22.3-66.9) or systemic chemotherapy (0%) had a shorter long-term survival (P = 0.001). CONCLUSION: Recurrence after surgery for NELM occurred among half of patients. Repeat liver resection for recurrence may offer a reasonable 5-year survival benefit.

Early Recurrence of Neuroendocrine Liver Metastasis After Curative Hepatectomy: Risk Factors, Prognosis, and Treatment.

BACKGROUND: Early tumor recurrence after curative resection typically indicates a poor prognosis. The objective of the current study was to investigate the risk factors, treatment, and prognosis of early recurrence of neuroendocrine tumor (NET) liver metastasis (NELM) after hepatic resection. METHODS: A total of 481 patients who underwent curative-intent resection for NELM were identified from a multi-institutional database. Data on clinicopathological characteristics, intraoperative details, and outcomes were documented. The optimal cutoff value to differentiate early and late recurrence was determined to be 3 years based on linear regression. RESULTS: With a median follow-up of 60 months, 223 (46.4%) patients developed a recurrence, including 158 (70.9%) early and 65 (29.1%) late recurrences. On multivariable analysis, pancreatic NET, primary tumor lymph node metastasis, and a microscopic positive surgical margin were independent risk factors for early intrahepatic recurrence. While recurrence patterns and treatments were comparable among patients with early and late recurrences, early recurrence was associated with worse disease-specific survival than late recurrences (10-year NELM-specific survival, 44.5 vs 75.8%, p < 0.001). Among the 34 (21.5%) patients who underwent curative treatment for early recurrence, post-recurrence disease-specific survival was better than non-curatively treated patients (10-year NELM-specific survival, 54.2 vs 26.3%, p = 0.028), yet similar to patients with late recurrences treated with curative intent (10-year NELM-specific survival, 54.2 vs 37.4%, p = 0.519). CONCLUSIONS: Early recurrence after surgery for NELM was associated with the pancreatic type, primary lymph node metastasis, and extrahepatic disease. Re-treatment with curative intent prolonged survival after recurrence, and therefore, operative intervention even for early recurrences of NELM should be considered.