Neuroendocrine Tumors of Unknown Primary in the Setting of Cytoreductive Hepatectomy.

BACKGROUND: Surgical cytoreduction for neuroendocrine tumor liver metastasis (NETLM) consistently shows positive long-term outcomes. Despite reservations in guidelines for surgery when the primary tumor is unidentified (UP-NET), this study compared the surgical and oncologic long-term outcomes between patients with these rare cases undergoing cytoreductive surgery and patients who had liver resection for known primaries. METHODS: The study identified 32 unknown primary liver metastases (UP-NETLM) in 522 retrospectively evaluated patients who underwent resection of well-differentiated NETLM between January 2000 and December 2020. Tumor and patient characteristics were compared with those in 490 cases of liver metastasis from small intestinal (SI-NETLM) or pancreatic (pNETLM) primaries. Survival analysis was performed to highlight long-term outcome differences. Surgical outcomes were compared between liver resections alone and simultaneous primary resections to assess surgical risk distinctions. RESULTS: The UP-NET patients had fewer NETLMs (p = 0.004), which on the average were larger than SI-NETLMs or pNETLMs (p = 0.002). Expression of Ki-67 was balanced among the groups. Major hepatectomy was performed more often in the UP-NETLM group (p = 0.017). The 10-year survival rate of 53% for UP-NETLM was comparable with that for SI-NETML (58%; p = 0.463) and pNETLMs (47%; p = 0.497). The median hepatic progression-free survival was 26 months for the UP-NETLM patients and 25 months for the SI-NETLM patients compared to 12 months for the pNETLM patients (p < 0.001). Perioperative mortality was lower than 2%, and severe postoperative morbidity occurred in 21%, similarly distributed among all the groups. CONCLUSION: The surgical risk and long-term outcomes for the UP-NETLM patients were comparable with those for other NETLM cases, affirming the validity of equally aggressive surgical cytoreduction as a therapeutic option in carefully selected cases.

Value of Surgical Cytoreduction in Patients with Small Intestinal Neuroendocrine Tumors Metastatic to the Liver and Peritoneum.

BACKGROUND: Cytoreductive hepatectomy can improve survival and symptoms of hormonal excess in patients with small intestinal neuroendocrine tumor (siNET) liver metastases, but whether to proceed when peritoneal metastases are encountered at the time of planned cytoreductive hepatectomy is controversial. METHODS: This was a retrospective review of patients who underwent surgical management of metastatic siNETs at Mayo Clinic between 2000 and 2020. Patients who underwent cytoreductive operation for isolated liver metastases or both liver and peritoneal metastases were compared. RESULTS: Of 261 patients who underwent cytoreductive operation for siNETs, 211 had isolated liver metastases and 50 had liver and peritoneal metastases. Complete cytoreduction was achieved in 78% of patients with isolated liver metastases and 56% of those with liver and peritoneal metastases (p = 0.002). After complete cytoreduction, median overall survival (OS) was 11.5 years for isolated liver metastases and 11.2 years for liver and peritoneal metastases (p = 0.10), and relief of carcinoid syndrome was ≥ 97% in both groups. After incomplete cytoreduction with debulking of > 90% of hepatic disease and/or closing Lyon score of 1-2, median OS was 6.4 years for isolated liver metastases and 7.1 years for liver and peritoneal metastases (p = 0.12). CONCLUSIONS: Patients with siNETs metastatic to both the liver and peritoneum have favorable outcomes after aggressive surgical cytoreduction, with the best outcomes observed after complete cytoreduction. Therefore, the presence of peritoneal metastases should not by itself preclude surgical cytoreduction in this population.

Minimally invasive vs. open approach to the simultaneous treatment of colorectal tumors with synchronous liver metastasis: a single center, propensity-score matched analysis from Mayo clinic.

BACKGROUND: Open combined resections of colorectal primary tumors and synchronous liver metastases have become common in selected cases. However, evidences favoring a minimally invasive (MIS) approach are still limited. The aim of this study is to evaluate the outcomes of MIS vs. open synchronous liver and colorectal resections. METHODS: 384 cases of synchronous colorectal and liver resections performed at one institution were identified during the study period. MIS vs open approach were compared after a propensity score matching; surgical outcomes were analyzed. RESULTS: MIS cases featured longer operative time (399 vs 300 min, p < 0.001), fewer blood loss (200 vs 500 ml, p = 0.003), and shorter hospitalization (median LOS 4 vs 6 days, p = 0.001). No difference was observed between the two groups for use of Pringle maneuver (p = 0.083), intraoperative blood transfusion (p = 0.061), achievement of negative colorectal (p = 0.176) and liver margins (p = 1.000), postoperative complications (p = 1.000) and significant (Clavien-Dindo ≥ 3a) complications (p = 0.817), delay of adjuvant therapy due to complications (p = 0.555), 30- and 90-day mortality. CONCLUSION: Synchronous colorectal and liver metastases resections via a minimally-invasive approach in high-volume centers with appropriate expertise result in significantly lower blood loss and length of stay despite longer operative time in comparison to open, with no oncological inferiority.

Survival and Symptomatic Relief After Cytoreductive Hepatectomy for Neuroendocrine Tumor Liver Metastases: Long-Term Follow-up Evaluation of More Than 500 Patients.

BACKGROUND: Distant metastases are the strongest predictor of poor prognosis for patients with neuroendocrine tumors (NETs). Cytoreductive hepatectomy (CRH) can relieve symptoms of hormonal excess and prolong survival for patients with liver metastases (NETLMs), but long-term outcomes are poorly characterized. METHODS: This retrospective single-institution analysis analyzed patients who underwent CRH for well-differentiated NETLMs from 2000 to 2020. Kaplan-Meier analysis estimated symptom-free interval and overall and progression-free survival. Multivariable Cox regression analysis evaluated factors associated with survival. RESULTS: The inclusion criteria were met by 546 patients. The most common primary sites were the small intestine (n = 279) and the pancreas (n = 194). Simultaneous primary tumor resection was performed for 60 % of the cases. Major hepatectomy comprised 27% of the cases, but this rate decreased during the study period (p < 0.001). Major complications occurred in 20%, and the 90-day mortality rate was 1.6%. Functional disease was present in 37 %, and symptomatic relief was achieved in 96%. The median symptom-free interval was 41 months (62 months after complete cytoreduction and 21 months with gross residual disease) (p = 0.021). The median overall survival was 122 months, and progression-free survival was 17 months. In the multivariable analysis, worse overall survival was associated with age, pancreatic primary tumor, Ki-67, number and size of lesions, and extrahepatic metastases, with Ki-67 as the strongest predictor (odds ratio [OR], 1.90 for Ki-67 [3-20%; p = 0.018] and OR, 4.25 for Ki-67 [>20%; p < 0.001]). CONCLUSION: The study showed that CRH for NETLMs is associated with low perioperative morbidity and mortality and excellent overall survival, although the majority will experience recurrence/progression. For patients with functional tumors, CRH can provide durable symptomatic relief.

Yield of Staging Laparoscopy for Pancreatic Cancer in the Modern Era: Analysis of More than 1,000 Consecutive Patients.

BACKGROUND: Accurate staging prior to resection of pancreatic ductal adenocarcinoma (PDAC) is imperative to avoid unnecessary operative morbidity and oncologic futility in patients with occult intra-abdominal distant metastases. We aimed to determine the diagnostic yield of staging laparoscopy (SL) and to identify factors associated with increased risk of positive laparoscopy (PL) in the modern era. STUDY DESIGN: Patients with radiographically localized PDAC who underwent SL from 2017 to 2021 were retrospectively reviewed. The yield of SL was defined as the proportion of patients with PL, including gross metastases and/or positive peritoneal cytology. Factors associated with PL were assessed using univariate analysis and multivariable logistic regression. RESULTS: Of 1,004 patients who underwent SL, 180 (18%) had PL due to gross metastases (n = 140) and/or positive cytology (n = 96). Patients who had neoadjuvant chemotherapy prior to laparoscopy had lower rates of PL (14% vs 22%, p = 0.002). When the analysis was restricted to chemo-naive patients who had concurrent peritoneal lavage performed, 95 of 419 patients (23%) had PL. In multivariable analysis, PL was associated with younger (<60) age, indeterminate extrapancreatic lesions on preoperative imaging, body/tail tumor location, larger tumor size, and elevated serum CA 19-9 (all p < 0.05). Among patients with no indeterminate extrapancreatic lesions on preoperative imaging, the rate of PL ranged from 1.6% in patients with no risk factors to 42% in young patients with large body/tail tumors and elevated serum CA 19-9. CONCLUSIONS: The rate of PL in patients with PDAC remains high in the modern era. SL with peritoneal lavage should be considered for the majority of patients prior to resection, specifically those with high-risk features, and ideally prior to neoadjuvant chemotherapy.

Laparoscopic versus open liver resections for intrahepatic cholangiocarcinoma and gallbladder cancer: the Mayo clinic experience.

BACKGROUND: Data regarding laparoscopic liver resections(LLRs) for Gallbladder cancer(GBC) and Intrahepatic Cholangiocarcinoma(iCCA) are sparse. This study compared LLRs with open liver resections(OLRs) in a high-volume center. METHODS: Data of patients who underwent LLR or OLR for GBC or iCCA at Mayo-Clinic between 01/2016 and 04/2021 were retrospectively compared. Proportional hazards models were used to compare the approach on survival. RESULTS: 32 and 52 patients underwent LLR and OLR during the study period, respectively. 64 and 20 patients had iCCA and GBC, respectively. LLR had lower median blood loss (250 mL vs. 475 mL, p = 0.001) and shorter median length of stay compared to OLR (3.0 days vs. 6.0 days, p = 0.001). LLR and OLR did not differ in post-operative major complication (25% vs. 32.7%, p = 0.62), negative margin (100% vs. 90.4%, p = 0.15) and completeness of lymphadenectomy rates (36.8% vs. 45.5%, p = 0.59). The median number of harvested lymph node was 4.0 and 5.0 for LLR and OLR, respectively (p = 0.347). There were no associations between approach and 3-year overall and disease-free survival between LLR and OLR (49.8% vs. 63.2% and 39.6% vs. 21.5%, p = 0.66 and p = 0.69). DISCUSSION: With appropriate patient selection and when compared to OLRs, LLRs for GBC and iCCA are feasible, safe and offer potential short-term benefits without compromising on oncological resection principals and long-term outcomes.

FDG-PET Predicts Neoadjuvant Therapy Response and Survival in Borderline Resectable/Locally Advanced Pancreatic Adenocarcinoma.

BACKGROUND: Neoadjuvant therapy (NAT) is used in borderline resectable/locally advanced (BR/LA) pancreatic ductal adenocarcinoma (PDAC). Anatomic imaging (CT/MRI) poorly predicts response, and biochemical (CA 19-9) markers are not useful (nonsecretors/nonelevated) in many patients. Pathologic response highly predicts survival post-NAT, but is only known postoperatively. Because metabolic imaging (FDG-PET) reveals primary tumor viability, this study aimed to evaluate our experience with preoperative FDG-PET in patients with BR/LA PDAC in predicting NAT response and survival. METHODS: We reviewed all patients with resected BR/LA PDAC who underwent NAT with FDG-PET within 60 days of resection. Pre- and post-NAT metabolic (FDG-PET) and biochemical (CA 19-9) responses were dichotomized in addition to pathologic responses. We compared post-NAT metabolic and biochemical responses as preoperative predictors of pathologic responses and recurrence-free survival (RFS) and overall survival (OS). RESULTS: We identified 202 eligible patients. Post-NAT, 58% of patients had optimization of CA 19-9 levels. Major metabolic and pathologic responses were present in 51% and 38% of patients, respectively. Median RFS and OS times were 21 and 48.7 months, respectively. Metabolic response was superior to biochemical response in predicting pathologic response (area under the curve, 0.86 vs 0.75; P<.001). Metabolic response was the only univariate preoperative predictor of OS (odds ratio, 0.25; 95% CI, 0.13-0.40), and was highly correlated (P=.001) with pathologic response as opposed to biochemical response alone. After multivariate adjustment, metabolic response was the single largest independent preoperative predictor (P<.001) for pathologic response (odds ratio, 43.2; 95% CI, 16.9-153.2), RFS (hazard ratio, 0.37; 95% CI, 0.2-0.6), and OS (hazard ratio, 0.21; 95% CI, 0.1-0.4). CONCLUSIONS: Among patients with post-NAT resected BR/LA PDAC, FDG-PET highly predicts pathologic response and survival, superior to biochemical responses alone. Given the poor ability of anatomic imaging or biochemical markers to assess NAT responses in these patients, FDG-PET is a preoperative metric of NAT efficacy, thereby allowing potential therapeutic alterations and surgical treatment decisions. We suggest that FDG-PET should be an adjunct and recommended modality during the NAT phase of care for these patients.

Patency rates of hepatic arterial resection and revascularization in locally advanced pancreatic cancer.

BACKGROUND: Arterial resection (AR) for pancreatic adenocarcinoma is increasingly considered at specialized centers. We aimed to examine the incidence, risk factors, and outcomes of hepatic artery (HA) occlusion after revascularization. METHODS: We included patients undergoing HA resection with interposition graft (IG) or primary end-to-end anastomoses (EE). Complete arterial occlusion (CAO) was defined as "early" (EO) or "late" (LO) before/after 90 days respectively. Kaplan-Meier and change-point analysis for CAO was performed. RESULTS: HA resection was performed in 108 patients, IG in 61% (66/108) and EE in 39% (42/108). An equal proportion (50%) underwent HA resection alone or in combination with celiac and/or superior mesenteric artery. CAO was identified in 18% of patients (19/108) with arterial IG least likely to occlude (p=0.019). Hepatic complications occurred in 42% (45/108) and correlated with CAO, symptomatic patients, venous resection, and postoperative portal venous patency. CAO-related operative mortality was 4.6% and significantly higher in EO vs LO (p = 0.046). Median CAO occlusion was 126 days. With change-point analysis, CAO was minimal beyond postoperative day 158. CONCLUSION: CAO can occur in up to 18% of patients and the first 5-month post-operative period is critical for surveillance. LO is associated with better outcomes compared to EO unless there is inadequate portal venous inflow.

Safety and Outcomes of Combined Pancreatic and Hepatic Resections for Metastatic Pancreatic Neuroendocrine Tumors.

BACKGROUND: Approximately 40-50% of patients with pancreatic neuroendocrine tumors (pNETs) initially present with distant metastases. Little is known about the outcomes of patients undergoing combined pancreatic and hepatic resections for this indication. METHODS: Patients who underwent hepatectomy for metastatic pNETs at Mayo Clinic Rochester from 2000 to 2020 were retrospectively reviewed. Major pancreatectomy was defined as pancreaticoduodenectomy or total pancreatectomy, and major hepatectomy as right hepatectomy or trisegmentectomy. Characteristics and outcomes of patients who underwent pancreatectomy with simultaneous hepatectomy were compared with those of patients who underwent isolated hepatectomy (with or without prior history of pancreatectomy). RESULTS: 205 patients who underwent hepatectomy for metastatic pNETs were identified: 131 underwent pancreatectomy with simultaneous hepatectomy and 74 underwent isolated hepatectomy. Among patients undergoing simultaneous hepatectomy, 89 patients underwent minor pancreatectomy with minor hepatectomy, 11 patients underwent major pancreatectomy with minor hepatectomy, 30 patients underwent minor pancreatectomy with major hepatectomy, and 1 patient underwent major pancreatectomy with major hepatectomy. Patients undergoing simultaneous hepatectomy had more numerous liver lesions (10 or more lesions in 54% vs. 34%, p = 0.008), but the groups were otherwise similar. Rates of any major complications (31% versus 24%, p = 0.43), hepatectomy-specific complications such as bile leak, hemorrhage, and liver failure (0.8-7.6% vs. 1.4-12%, p = 0.30-0.99), and 90-day mortality (1.5% vs. 2.7%, p = 0.62) were similar between the two groups. 5-year overall survival was 64% after combined resections and 65% after isolated hepatectomy (p = 0.93). CONCLUSION: For patients with metastatic pNETs, combined pancreatic and hepatic resections can be performed with acceptable morbidity and mortality in selected patients at high-volume institutions.

Hepatocellular carcinoma as predominant cancer subgroup accounting for sex differences in post-hepatectomy liver failure, morbidity and mortality.

BACKGROUND: Experimental evidence suggests sex dependent differences in liver regeneration. Limited evidence is available examining sex differences in post-hepatectomy liver failure (PHLF) and postoperative outcomes. Our aim was to assess the influence of sex on the outcomes after liver resection. METHODS: The hepatectomy targeted National Surgical Quality Improvement Program (NSQIP) database was assessed for associations between sex and outcomes. RESULTS: A total of 13,401 patients underwent elective hepatic resection between 2014-2017. PHLF was highest among male patients with hepatocellular carcinoma (HCC) (OR = 2.81,95%CI:1.40-5.62). Male sex was independently associated with increased PHLF (OR = 1.47,95%CI:1.15-1.88), major complications (OR = 1.25,95%CI:1.08-1.45), mortality (OR = 1.61,95%CI:1.03-2.50), and if only major resections were assessed (OR = 1.38,95%CI:1.03-1.84). Diagnosis specific subgroup analyses revealed that effects of sex were predominantly HCC associated. CONCLUSIONS: This is the largest series investigating the effects of gender on outcomes after hepatic resection. We documented that women undergoing liver resection have significantly lower risk of PHLF. This difference seemed influenced by the striking increase of PHLF in male HCC patients. These hypothesis suggest that sex might play a role in preoperative risk stratification.

Contemporary outcomes of pancreaticoduodenectomy for benign and precancerous cystic lesions.

BACKGROUND: The decision to undertake pancreaticoduodenectomy for benign and precancerous lesions has historically relied on outcomes data from operations for cancer. We aimed to describe risks for these specific patients and identify the highest risk groups. METHODS: The ACS-NSQIP pancreatic targeted data was queried for pancreaticoduodenectomies for benign and pre-cancerous neoplasms from 2014 to 2018. Baseline characteristics, operative techniques and outcomes were examined. Multivariate regression was performed to identify predictors of major complications. RESULTS: 748 patients underwent pancreaticoduodenectomy for (n = 541,72.3%) IPMN, (n = 87,11.6%) MCN, (n = 78,10.4%) serous cystadenoma, and (n = 42,5.6%) solid pseudopapillary neoplasm. Median LOS was 8 days. Major complications (n = 135,18.0%), non-home discharges (n = 83,11.1%) and readmissions (n = 153,20.5%) occurred frequently. In patients ≥ 80 years of age (n = 37), major complications (n = 11,29.7%) and non-home discharge (n = 9,24.3%) were quite common. 5-item modified frailty index ≥ 0.4 (OR 1.84,95%CI 1.06-3.19,p = 0.030), Male sex (OR 1.729,95%CI 1.152-2.595,p = 0.008), Age ≥ 65 (OR 1.63,95%CI 1.05-2.54,p = 0.29) and African-American race (OR 2.50,95%CI 1.22-5.16,p = 0.013) were independent predictors of major morbidity. CONCLUSIONS: Pancreaticoduodenectomies in this setting have high rates of major complications. Morbidity extends beyond the index hospitalization, with frequent readmission and non-home discharge. Patient specific factors, rather than technical or disease factors predicted outcomes. In certain patients, particularly those older than 80, the morbidity of this operation may exceed the cancer prevention benefits.

Outcomes of pancreatectomy with portomesenteric venous resection and reconstruction for locally advanced pancreatic neuroendocrine neoplasms.

BACKGROUND: While pancreatectomy with portomesenteric venous resection and reconstruction is commonly performed for locally advanced pancreatic adenocarcinoma, little is known regarding outcomes for pancreatic neuroendocrine neoplasms (panNENs). METHODS: Patients who underwent non-parenchyma-sparing pancreatectomy for panNENs at Mayo Clinic from 2000 to 2020 were retrospectively reviewed. Propensity score matching was performed and patient characteristics and outcomes compared. RESULTS: Of 867 eligible patients, 41 (4.7%) required vascular resection, including 38 patients who underwent portomesenteric venous resection only. Of these, 23 underwent pancreaticoduodenectomy or total pancreatectomy and 15 distal pancreatectomy. Patients who required portomesenteric venous resection had larger tumors, higher tumor grade, and higher disease stage. After propensity score matching to patients undergoing standard resection, the portomesenteric venous resection group had longer operative times, greater blood loss, and higher transfusion rates. While portomesenteric venous thrombosis was more common after venous resection, major complication rates and perioperative mortality were similar between the two groups, as were 5-year overall and progression-free survival. CONCLUSION: For patients with locally advanced panNENs, pancreatectomy with portomesenteric venous resection and reconstruction can be performed in selected patients at high-volume centers with acceptable perioperative morbidity and short- and long-term survival.