Accuracy and Prognostic Impact of Nodal Status on Preoperative Imaging for Management of Pancreatic Neuroendocrine Tumors: A Multi-Institutional Study.

BACKGROUND: We sought to define the accuracy of preoperative imaging to detect lymph node metastasis (LNM) among patients with pancreatic neuroendocrine tumors (pNETs), as well as characterize the impact of preoperative imaging nodal status on survival. METHODS: Patients who underwent curative-intent resection for pNETs between 2000 and 2020 were identified from eight centers. Sensitivity and specificity of computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET)-CT, and OctreoScan for LNM were evaluated. The impact of preoperative lymph node status on lymphadenectomy (LND), as well as overall and recurrence-free survival was defined. RESULTS: Among 852 patients, 235 (27.6%) individuals had LNM on final histologic examination (hN1). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 12.4%, 98.1%, 71.8%, and 74.4% for CT, 6.3%, 100%, 100%, and 80.1% for MRI, 9.5%, 100%, 100%, and 58.7% for PET, 11.3%, 97.5%, 66.7%, and 70.8% for OctreoScan, respectively. Among patients with any combination of these imaging modalities, overall sensitivity, specificity, PPV, and NPV was 14.9%, 97.9%, 72.9%, and 75.1%, respectively. Preoperative N1 on imaging (iN1) was associated with a higher number of LND (iN1 13 vs. iN0 9, p = 0.003) and a higher frequency of final hN1 versus preoperative iN0 (iN1 72.9% vs. iN0 24.9%, p < 0.001). Preoperative iN1 was associated with a higher risk of recurrence versus preoperative iN0 (median recurrence-free survival, iN1→hN1 47.5 vs. iN0→hN1 92.7 months, p = 0.05). CONCLUSIONS: Only 4% of patients with LNM on final pathologic examine had preoperative imaging that was suspicious for LNM. Traditional imaging modalities had low sensitivity to determine nodal status among patients with pNETs.

Low Prognostic Nutritional Index Is Common and Associated with Poor Outcomes following Curative-Intent Resection for Gastro-Entero-Pancreatic Neuroendocrine Tumors.

INTRODUCTION: To investigate the impact of prognostic nutritional index (PNI) on short- and long-term outcomes of patients who underwent curative-intent resection for gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs). METHODS: Patients with GET-NETs who underwent curative-intent resection were identified from a multi-center database. The prognostic impact of clinicopathological factors including PNI on post-operative outcomes were evaluated. A novel nomogram was developed and externally validated. RESULTS: A total of 2,099 patients with GEP-NETs were included in the training cohort; 255 patients were in the external validation cohort. Median PNI (n = 973) was 47.4 (IQR 43.1-52.4). At the time of presentation, 1,299 (61.9%) patients presented with some type of clinical symptom. Low-PNI (≤42.2) was associated with gastrointestinal symptoms, as well as nodal metastasis and distant metastasis (all p < 0.05). Patients with a low PNI had a higher incidence of severe (≥Clavien-Dindo grade IIIa: low PNI 24.9% vs. high PNI 15.4%, p = 0.001) and multiple (≥3 types of complications: low PNI 14.5% vs. high PNI 9.2%, p = 0.024) complications, as well as a worse overall survival (OS)(5-year OS, low PNI 73.7% vs. high PNI 88.5%, p < 0.001), and RFS (5-year RFS, low PNI 68.5% vs. high PNI 79.8%, p = 0.008) versus patients with high PNI (>42.2). A nomogram based on PNI, tumor grade and metastatic disease demonstrated excellent discrimination and calibration to predict OS in both the training (C-index 0.748) and two external validation (C-index 0.827, 0.745) cohorts. CONCLUSIONS: Low PNI was common and associated with worse short- and long-term outcomes among patients with GEP-NETs.

Association of Surgical Approaches and Outcomes in Total Mesorectal Excision and Margin Status for Rectal Cancer.

INTRODUCTION: Despite being a key metric with a significant correlation with the outcomes of patients with rectal cancer, the optimal surgical approach for total mesorectal excision (TME) has not yet been identified. The aim of this study was to assess the association of the surgical approach on the quality of TME and surgical margins and to characterize the surgical and long-term oncologic outcomes in patients undergoing robotic, laparoscopic, and open TME for rectal cancer. METHODS: Patients with primary, nonmetastatic rectal adenocarcinoma who underwent either lower anterior resection or abdominoperineal resection via robotic (Rob), laparoscopic (Lap), or open approaches were selected from the US Rectal Cancer Consortium database (2007-2017). Quasi-Poisson regression analysis with backward selection was used to investigate the relationship between the surgical approach and outcomes of interest. RESULTS: Among the 664 patients included in the study, the distribution of surgical approaches was as follows: 351 (52.9%) underwent TME via the open approach, 159 (23.9%) via the robotic approach, and 154 (23.2%) via the laparoscopic approach. There were no significant differences in baseline demographics among the three cohorts. The laparoscopic cohort had fewer patients with low rectal cancer (<6 cm from the anal verge) than the robotic and open cohorts (Lap 28.6% versus Rob 59.1% versus Open 45.6%, P = 0.015). Patients who underwent Rob and Lap TME had lower intraoperative blood loss compared with the Open approach (Rob 200 mL [Q1, Q3: 100.0, 300.0] versus Lap 150 mL [Q1, Q3: 75.0, 250.0] versus Open 300 mL [Q1, Q3: 150.0, 600.0], P < 0.001). There was no difference in the operative time (Rob 243 min [Q1, Q3: 203.8, 300.2] versus Lap 241 min [Q1, Q3: 186, 336] versus Open 226 min [Q1, Q3: 178, 315.8], P = 0.309) between the three approaches. Postoperative length of stay was shorter with robotic and laparoscopic approach compared to open approach (Rob 5.0 d [Q1, Q3: 4, 8.2] versus Lap 5 d [Q1, Q3: 4, 8] versus Open 7.0 d [Q1, Q3: 5, 9], P < 0.001). There was no statistically significant difference in the quality of TME between the robotic, laparoscopic, and open approaches (79.2%, 64.9%, and 64.7%, respectively; P = 0.46). The margin positivity rate, a composite of circumferential margin and distal margin, was higher with the robotic and open approaches than with the laparoscopic approach (Rob 8.2% versus Open 6.6% versus Lap 1.9%, P = 0.17), Rob versus Lap (odds ratio 0.21; 95% confidence interval 0.05, 0.83) and Rob versus Open (odds ratio 0.5; 95% confidence interval 0.22, 1.12). There was no difference in long-term survival, including overall survival and recurrence-free survival, between patients who underwent robotic, laparoscopic, or open TME (Figure 1). CONCLUSIONS: In patients undergoing surgery with curative intent for rectal cancer, we did not observe a difference in the quality of TME between the robotic, laparoscopic, or open approaches. Robotic and open TME compared to laparoscopic TME were associated with higher margin positivity rates in our study. This was likely due to the higher percentage of low rectal cancers in the robotic and open cohorts. We also reported no significant differences in overall survival and recurrence-free survival between the aforementioned surgical techniques.

Impact of neoadjuvant immunotherapy on postoperative complications after surgery for rectal cancer.

INTRODUCTION: Despite the increasing use of immunotherapy in treating various cancer types, there is still limited understanding of its impact on surgical complications. We used a national database to examine the difference in surgical outcomes for rectal cancer patients who received standard neoadjuvant chemoradiation plus neoadjuvant immunotherapy and patients who received neoadjuvant chemoradiation only. METHODS: This retrospective cohort study used the National Cancer Database (NCDB). We selected patients aged 18-90 with T1-3, N1-2, and M0 rectal cancer who underwent curative-intent surgery between 2010 and 2020. We performed a 1:1 propensity match to control for patient age, sex, Charlson-Deyo comorbidity index, surgical approach, and tumor site. Our primary outcome was difference in surgical outcomes (hospital length of stay, unplanned 30-day readmission, 30-day mortality) between the two groups. Secondary outcomes included days from diagnosis to surgery and pathologic outcomes. RESULTS: Our study included 26 229 patients, of which 126 received immunotherapy in addition to chemoradiation and 26 103 received only chemoradiation. In our matched population of 125 pairs of patients, patients who received immunotherapy and chemoradiation underwent surgery later compared to patients who only received chemoradiation (median 245 vs. 144 days, p < 0.001). There were no significant differences in median length of stay (5 vs. 5 days, p = 0.202), unplanned 30-day readmission (7 vs. 9, p = 0.617), and 30-day mortality (0 vs. 1, p = 1.000) between the two groups. CONCLUSION: Neoadjuvant immunotherapy for rectal cancer is not associated with adverse surgical outcomes. This work can help clinicians optimize treatment protocols and move closer toward strategies tailored to specific patient profiles.

Calcifications and Cystic Morphology on Preoperative Imaging Predict Survival After Resection of Pancreatic Neuroendocrine Tumors.

BACKGROUND: Radiographic calcifications and cystic morphology are associated with higher and lower tumor grade, respectively, in pancreatic neuroendocrine tumors (PNETs). Whether calcifications and/or cystic morphology could be used preoperatively to predict post-resection survival in patients with PNETs remains elusive. METHODS: Patients undergoing curative-intent resection of well-differentiated PNETs from 2000 to 2017 at eight academic institutions participating in the US Neuroendocrine Tumor Study Group were identified. Preoperative cross-sectional imaging reports were reviewed to identify the presence of calcifications and of a cystic component occupying >50% of the total tumor area. Clinicopathologic characteristics and recurrence-free survival (RFS) were compared. RESULTS: Of 981 patients studied, 18% had calcifications and 17% had cystic tumors. Tumors with calcifications were more commonly associated with Ki-67 ≥3% (47% vs. 33%; p = 0.029), lymph node metastasis (36% vs. 24%; p = 0.011), and distant metastasis (13% vs. 4%; p < 0.001). In contrast, cystic tumors were less commonly associated with lymph node metastasis (12% vs. 30%; p < 0.001). Five-year RFS after resection was most favorable for cystic tumors without calcifications (91%), intermediate for solid tumors without calcifications (77%), and least favorable for any calcified PNET (solid 69%, cystic 67%; p = 0.043). Calcifications remained an independent predictor of RFS on multivariable analysis (p = 0.043) controlling for nodal (p < 0.001) and distant metastasis (p = 0.001). CONCLUSIONS: Easily detectable radiographic features, such as calcifications and cystic morphology, can be used preoperatively to stratify prognosis in patients with PNETs and possibly inform the decision to operate or not, as well as guide the extent of resection and potential use of neoadjuvant therapy.

Association of Systemic Chemotherapy Approaches With Outcomes in Appendiceal Peritoneal Metastases.

INTRODUCTION: Many patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) for appendiceal adenocarcinoma peritoneal metastases (APM) undergo preoperative systemic chemotherapy. The primary aim of this study is to evaluate differences in oncologic outcomes among two popular chemotherapy approaches in patients with APM undergoing CRS-HIPEC. METHODS: We performed a multicenter retrospective review of patients who underwent CRS-HIPEC for APM due to high or intermediate grade disease between 2013 and 2019. Patients in the total neoadjuvant therapy group (TNT) received 12 cycles of preoperative chemotherapy. Patients in the "sandwich" chemotherapy group (SAND) received six cycles of preoperative chemotherapy with a maximum of six cycles of postoperative chemotherapy. The primary outcomes were overall survival (OS) and recurrence-free survival (RFS) defined as months from date of first treatment or surgery, respectively. RESULTS: A total of 39 patients were included in this analysis, with 25 (64%) patients in the TNT group and 14 (36%) patients in the SAND group. Patients in the TNT group had a median OS of 62 mo, while median OS in the SAND group was 45 mo (P = 0.01). In addition, patients in the TNT group had significantly longer RFS compared to the SAND group (35 versus 12 mo, P = 0.03). In a multivariable analysis, TNT approach was independently associated with improved OS and RFS. CONCLUSIONS: In this multicenter retrospective analysis, a TNT approach was associated with improved overall and recurrence-free survival compared to a sandwiched chemotherapy approach in patients undergoing CRS-HIPEC for high or intermediate grade APM.

A total neoadjuvant chemotherapy approach is associated with improved recurrence-free survival in patients with colorectal peritoneal metastases undergoing cytoreductive surgery and HIPEC.

BACKGROUND: The primary aim of this study is to evaluate the oncologic outcomes of two popular systemic chemotherapy approaches in patients with colorectal peritoneal metastases (CPM) undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). METHODS: We performed a dual-center retrospective review of consecutive patients who underwent CRS-HIPEC for CPM due to high or intermediate-grade colorectal cancer. Patients in the total neoadjuvant therapy (TNT) group received 6 months of preoperative chemotherapy. Patients in the "sandwich" (SAND) chemotherapy group received 3 months of preoperative chemotherapy with a maximum of 3 months of postoperative chemotherapy. RESULTS: A total of 34 (43%) patients were included in the TNT group and 45 (57%) patients in the SAND group. The median overall survival (OS) in the TNT and SAND groups were 77 and 61 months, respectively (p = 0.8). Patients in the TNT group had significantly longer recurrence-free survival (RFS) than the SAND group (29 vs. 12 months, p = 0.02). In a multivariable analysis, the TNT approach was independently associated with improved RFS. CONCLUSION: In this retrospective study, a TNT approach was associated with improved RFS, but not OS when compared with a SAND approach. Further prospective studies are needed to examine these systemic chemotherapeutic approaches in patients with CPM undergoing CRS-HIPEC.

Outcomes of robotic-assisted liver surgery versus laparoscopic liver surgery for treatment of stage I hepatocellular carcinoma.

BACKGROUND: This article investigated whether robotic-assisted liver surgery versus laparoscopic liver surgical treatment of hepatocellular carcinoma (HCC) has similar or different short- and long-term clinical outcomes. METHODS: A total of 3049 patients from the National Cancer Database who received minimally invasive surgery (ie, robotic or laparoscopic surgery) for stage I HCC cancers between 2010 to 2015, of which 123 had robotic and 2926 had laparoscopic surgeries performed, were identified. Logistic regression was applied to evaluate short-term outcomes. Cox proportional hazards models were applied to estimate all-cause mortality at 1-year, 3-years, and 5-years after surgery, adjusting for potential confounders. Propensity score-matched analyses were conducted to compare long-term outcomes between robotic and laparoscopic surgeries. RESULTS: Robotic surgery was associated with improved overall survival, with 1-, 3-, and 5-year survival rates (SRs) of 0.92, 0.75, and 0.63 compared with laparoscopic surgery SRs of 0.86, 0.60, and 0.45, respectively (P value <.01). Multivariate analyses showed that robotic compared with laparoscopic surgery had significantly lower 5-year total mortality (hazard ratio [HR], 0.64 and 95% confidence interval [CI], 0.45%-0.93% for intent-to-treat; HR, 0.62 and 95% CI, 0.42%-0.91% for end-treatment analyses). Similar results were found in propensity score matched analyses; robotic surgery was associated with improved overall survival compared with laparoscopic surgery (HR, 0.64 and 95% CI, 0.43%-0.96% for intent-to-treat; HR, 0.59 and 95% CI, 0.39%-0.90% for end-treatment). CONCLUSIONS: Robotic surgery is not inferior to laparoscopic surgery in treating early-stage HCC and may be associated with improved long-term survival.

Development and Validation of a Modified Eighth AJCC Staging System for Primary Pancreatic Neuroendocrine Tumors.

OBJECTIVE: To improve the prognostic accuracy of the eighth edition of AJCC staging system for pNETs with establishment and validation of a new staging system. BACKGROUND: Validation of the updated eighth AJCC staging system for pNETs has been limited and controversial. METHODS: Data from the SEER registry (1975-2016) (n = 3303) and a multi-institutional database (2000-2016) (n = 825) was used as development and validation cohorts, respectively. A mTNM was proposed by maintaining the eighth AJCC T and M definitions, and the recently proposed N status as N0 (no LNM), N1 (1-3 LNM), and N2 (≥4 LNM), but adopting a new stage classification. RESULTS: The eighth TNM staging system failed to stratify patients with stage I versus IIA, stage IIB versus IIIA, and overall stage I versus II relative to long-term OS in both database. There was a monotonic decrement in survival based on the proposed mTNM staging classification among patients derived from both the SEER (5-year OS, stage I 87.0% vs stage II 80.3% vs stage III 72.9% vs stage IV 57.2%, all P < 0.001), and multi-institutional (5-year OS, stage I 97.6% vs stage II 82.7% vs stage III 78.4% vs stage IV 50.0%, all P < 0.05) datasets. On multivariable analysis, mTNM staging remained strongly associated with prognosis, as the hazard of death incrementally increased with each stage among patients in the 2 cohorts. CONCLUSION: A mTNM pNETs clinical staging system using N0, N1, N2 nodal categories was better at stratifying patients relative to long-term OS than the eighth AJCC staging.

Impact of Insurance Status on Oncologic and Perioperative Outcomes After Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy.

BACKGROUND: A growing body of research has shown that underinsured patients are at increased risk of worse health outcomes compared with insured patients. Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is largely performed at highly specialized cancer centers and may pose challenges for the underinsured. This study investigates surgical outcomes following CRS-HIPEC for insured and underinsured patients with peritoneal carcinomatosis. METHODS: We performed a retrospective cohort study of 125 patients undergoing CRS-HIPEC between 2013 and 2019. Patients were categorized into two groups. The insured group was comprised of patients with private insurance at the time of CRS-HIPEC or who obtained it during the follow-up period. The underinsured group consisted of patients with Medicaid, or self-pay. Perioperative and oncologic outcomes were compared between the two groups. RESULTS: A total of 102 (82.3%) patients were insured, and 22 (17.7%) patients were underinsured. There were no significant differences in age, medical morbidities, primary tumor characteristics, peritoneal carcinomatosis index, or completion of cytoreduction score between the two groups. The median overall survival (OS) for insured patients was 64.8 months and was 52.9 months for underinsured patients (p = 0.01). Additionally, insured patients had a significantly longer follow-up time. Underinsurance status also was associated with increased hospital and intensive care unit length of stay, and higher rate of Clavien-Dindo classification III-IV complications. CONCLUSIONS: In this retrospective study conducted at a large, urban, specialized cancer center, private insurance status was associated with increased overall survival and longer follow-up period. Furthermore, underinsurance status was associated with increased perioperative morbidity.

Prognostic Utility of Systemic Immune-Inflammation Index After Resection of Extrahepatic Cholangiocarcinoma: Results from the U.S. Extrahepatic Biliary Malignancy Consortium.

BACKGROUND: We sought to define the association of the systemic immune inflammation index (SII) with prognosis and adjuvant therapy benefit among patients undergoing resection of extrahepatic cholangiocarcinoma (eCCA). METHODS: The impact of SII on overall (OS) and recurrence-free survival (RFS) following resection of eCCA was assessed and compared with other inflammatory markers and traditional prognostic factors. Propensity score matching (PSM) was used to determine the impact of adjuvant therapy (AT) on OS and RFS relative to low versus high SII. RESULTS: Patients with high versus low SII had worse 5-year OS (15.9% vs. 27.9%) and RFS (12.4% vs. 20.9%) (both p < 0.01). On multivariate analysis, high SII remained associated with worse OS (HR = 1.50, 95% CI 1.20-1.87) and RFS (HR = 1.46, 95% CI 1.18-1.81). Patients with T1/2 disease and a high-SII had worse 5-year OS versus individuals with T3/4 disease and low-SII (5-year OS: T1/2 & low-SII 35.6%, T1/2 & high-SII 16.4%, T3/4 & low-SII 22.1%, T3/4 & high-SII 15.6%, p < 0.01). Similarly, 5-year OS was comparable among individuals with N0 and high-SII versus N1 and low-SII (5-year OS: N0 & high-SII 23.2%, N1 and low-SII 19.8%, p = 0.95). On PSM, AT improved OS and RFS among patients with high SII (5-year OS: 22.5% vs. 12.3%, p < 0.01, 5-year RFS: 19.0% vs. 12.5%; p = 0.01) but not individuals with low SII (5-year OS: 22.9% vs. 26.9%; p = 0.98, 5-year RFS: 18.5% vs. 19.9%; p = 0.94). CONCLUSIONS: SII was independently associated with postoperative OS and RFS following curative-intent resection of eCCA. High SII up-staged patients relative T- and N-categories and identified patients with high SII as the most likely to benefit from AT.

Surgical outcomes of gastro-entero-pancreatic neuroendocrine tumors G3 versus neuroendocrine carcinoma.

BACKGROUND: To define surgical outcomes of patients with high-grade gastro-entero-pancreatic neuroendocrine neoplasm grade G3 (GEP-NEN G3). METHODS: Patients who underwent surgical resection between 2000 and 2016 were identified. The overall survival (OS) and recurrence-free survival (RFS) of patients with gastro-entero-pancreatic neuroendocrine tumors grade G3 (GEP-NET G3) versus neuroendocrine carcinoma (NEC) were evaluated. RESULTS: Fifty-one out of 2182 (2.3%) patients who underwent surgical resection were diagnosed as GEP-NEN G3. The pancreas was the most common primary site (n = 3772.5%). A majority of patients had lymph node metastasis (n = 3262.7%); one in three (n = 1631.4%) had distant metastasis. The median OS and RFS of the entire cohort were 56.4 and 34.5 months, respectively. Perineural invasion was a strong prognostic factor associate with OS after surgical resection. Patients with NEC had a worse survival outcome versus patients with NET G3 (median OS: 33.1 months vs. not attained, p = 0.088). In contrast, among patients who underwent curative-intent resection, patients with NEC had comparable RFS versus patients with NET G3 (median RFS: 35.6 vs. 33.9 months, p = 0.774). CONCLUSIONS: Surgical resection provided acceptable short- and long-outcomes for well-selected patients with resectable GEP-NEN G3. NEC was associated with a worse OS versus NET G3.

Using machine learning to preoperatively stratify prognosis among patients with gallbladder cancer: a multi-institutional analysis.

BACKGROUND: Gallbladder cancer (GBC) is an aggressive malignancy associated with a high risk of recurrence and mortality. We used a machine-based learning approach to stratify patients into distinct prognostic groups using preperative variables. METHODS: Patients undergoing curative-intent resection of GBC were identified using a multi-institutional database. A classification and regression tree (CART) was used to stratify patients relative to overall survival (OS) based on preoperative clinical factors. RESULTS: CART analysis identified tumor size, biliary drainage, carbohydrate antigen 19-9 (CA19-9) levels, and neutrophil-lymphocyte ratio (NLR) as the factors most strongly associated with OS. Machine learning cohorted patients into four prognostic groups: Group 1 (n = 109): NLR ≤1.5, CA19-9 ≤20, no drainage, tumor size <5.0 cm; Group 2 (n = 88): NLR >1.5, CA19-9 ≤20, no drainage, tumor size <5.0 cm; Group 3 (n = 46): CA19-9 >20, no drainage, tumor size <5.0 cm; Group 4 (n = 77): tumor size <5.0 cm with drainage OR tumor size ≥5.0 cm. Median OS decreased incrementally with CART group designation (59.5, 27.6, 20.6, and 12.1 months; p < 0.0001). CONCLUSIONS: A machine-based model was able to stratify GBC patients into four distinct prognostic groups based only on preoperative characteristics. Characterizing patient prognosis with machine learning tools may help physicians provide more patient-centered care.

New Nodal Staging for Primary Pancreatic Neuroendocrine Tumors: A Multi-institutional and National Data Analysis.

OBJECTIVE: To determine the prognostic role of metastatic lymph node (LN) number and the minimal number of LNs for optimal staging of patients with pancreatic neuroendocrine tumors (pNETs). BACKGROUND: Prognosis relative to number of LN metastasis (LNM), and minimal number of LNs needed to evaluate for accurate staging, have been poorly defined for pNETs. METHODS: Number of LNM and total number of LN evaluated (TNLE) were assessed relative to recurrence-free survival (RFS) and overall survival (OS) in a multi-institutional database. External validation was performed using Surveillance, Epidemiology and End Results (SEER) registry. RESULTS: Among 854 patients who underwent resection, 233 (27.3%) had at least 1 LNM. Patients with 1, 2, or 3 LNM had a comparable worse RFS versus patients with no nodal metastasis (5-year RFS, 1 LNM 65.6%, 2 LNM 68.2%, 3 LNM 63.2% vs 0 LNM 82.6%; all P < 0.001). In contrast, patients with ≥4 LNM (proposed N2) had a worse RFS versus patients who either had 1 to 3 LNM (proposed N1) or node-negative disease (5-year RFS, ≥4 LNM 43.5% vs 1-3 LNM 66.3%, 0 LNM 82.6%; all P < 0.05) [C-statistics area under the curve (AUC) 0.650]. TNLE ≥8 had the highest discriminatory power relative to RFS (AUC 0.713) and OS (AUC 0.726) among patients who had 1 to 3 LNM, and patients who had ≥4 LNM in the multi-institutional and SEER database (n = 2764). CONCLUSIONS: Regional lymphadenectomy of at least 8 lymph nodes was necessary to stage patients accurately. The proposed nodal staging of N0, N1, and N2 optimally staged patients.

Defining and Predicting Early Recurrence after Resection for Gallbladder Cancer.

BACKGROUND: The optimal time interval to define early recurrence (ER) among patients who underwent resection of gallbladder cancer (GBC) is not well defined. We sought to develop and validate a novel GBC recurrence risk (GBRR) score to predict ER among patients undergoing resection for GBC. PATIENTS AND METHODS: Patients who underwent curative-intent resection for GBC between 2000 and 2018 were identified from the US Extrahepatic Biliary Malignancy Consortium database. A minimum p value approach in the log-rank test was used to define the optimal cutoff for ER. A risk stratification model was developed to predict ER based on relevant clinicopathological factors and was externally validated. RESULTS: Among 309 patients, 103 patients (33.3%) had a recurrence at a median follow-up period of 15.1 months. The optimal cutoff for ER was defined at 12 months (p = 3.04 × 10-18). On multivariable analysis, T3/T4 disease (HR: 2.80; 95% CI 1.58-5.11) and poor tumor differentiation (HR: 1.91; 95% CI 1.11-3.25) were associated with greater hazards of ER. The GBRR score was developed using ß-coefficients of variables in the final model, and patients were classified into three distinct groups relative to the risk for ER (12-month RFS; low risk: 88.4%, intermediate risk: 77.9%, high risk: 37.0%, p < 0.001). The external validation demonstrated good model generalizability with good calibration (n = 102: 12-month RFS; low risk: 94.2%, intermediate risk: 59.8%, high risk: 42.0%, p < 0.001). The GBRR score is available online at https://ktsahara.shinyapps.io/GBC_earlyrec/ . CONCLUSIONS: A novel online calculator was developed to help clinicians predict the probability of ER after curative-intent resection for GBC. The proposed web-based tool may help in the optimization of surveillance intervals and the counselling of patients about their prognosis.

Defining the Risk of Early Recurrence Following Curative-Intent Resection for Distal Cholangiocarcinoma.

BACKGROUND: Although multidisciplinary treatments including the use of adjuvant therapy (AT) have been adopted for biliary tract cancers, patients with distal cholangiocarcinoma (DCC) can still experience recurrence. We sought to characterize the incidence and predictors of early recurrence (ER) that occurred within 12 months following surgery for DCC. PATIENTS AND METHODS: Patients who underwent resection for DCC between 2000 and 2015 were identified from the US multi-institutional database. Cox regression analysis was used to identify clinicopathological factors to develop an ER risk score, and the predictive model was validated in an external dataset. RESULTS: Among 245 patients included in the analysis, 67 patients (27.3%) developed ER. No difference was noted in ER rates between patients who did and did not receive AT (28.7% vs. 25.0%, p = 0.55). Multivariable analysis revealed that neutrophil-to-lymphocyte ratio (NLR), peak total bilirubin (T-Bil), major vascular resection (MVR), lymphovascular invasion, and R1 surgical margin status were associated with a higher ER risk. A DIstal Cholangiocarcinoma Early Recurrence Score was developed according to each factor available prior to surgery [NLR > 9.0 (2 points); peak T-bil > 1.5 mg/dL (1 points); MVR (2 points)]. Cumulative ER rates incrementally increased among patients who were low (0 points; 10.6%), intermediate (1-2 points; 26.8%), or high (3-5 points; 57.6%) risk (p < 0.001) in the training dataset, as well as in the validation dataset [low (0 points); 3.4%, intermediate (1-2 points); 32.7%, or high risk (3-5 points); 55.6% (p < 0.001)]. CONCLUSIONS: Among patients undergoing resection for DCC, 1 in 4 patients experienced an ER. Alternative treatment strategies such as neoadjuvant chemotherapy may be considered especially among individuals deemed to be at high risk for ER.

Long-Term Outcomes after Spleen-Preserving Distal Pancreatectomy for Pancreatic Neuroendocrine Tumors: Results from the US Neuroendocrine Study Group.

BACKGROUND: The adoption of spleen-preserving distal pancreatectomy (SPDP) for malignant disease such as pancreatic neuroendocrine tumors (pNETs) has been controversial. The objective of the current study was to assess the impact of SPDP on outcomes of patients with pNETs. METHODS: Patients undergoing a distal pancreatectomy for pNET between 2002 and 2016 were identified in the US Neuroendocrine Tumor Study Group database. Propensity score matching (PSM) was used to compare short- and long-term outcomes of patients undergoing SPDP versus distal pancreatectomy with splenectomy (DPS). RESULTS: Among 621 patients, 103 patients (16.6%) underwent an SPDP. Patients who underwent SPDP were more likely to have lower BMI (median, 27.5 [IQR 24.0-31.2] vs. 28.7 [IQR 25.7-33.6]; p = 0.005) and have undergone minimally invasive surgery (n = 56, 54.4% vs. n = 185, 35.7%; p < 0.001). After PSM, while the median total number of lymph nodes examined among patients who underwent an SPDP was lower compared with DPS (3 [IQR 1-8] vs. 9 [5-13]; p < 0.001), 5-year overall survival (OS) and recurrence-free survival (RFS) were comparable (OS: 96.8 vs. 92.0%, log-rank p = 0.21, RFS: 91.1 vs. 84.7%, log-rank p = 0.93). In addition, patients undergoing SPDP had less intraoperative blood loss (median, 100 mL [IQR 10-250] vs. 150 mL [IQR 100-400]; p = 0.001), lower incidence of serious complications (n = 13, 12.8% vs. n = 28, 27.5%; p = 0.014), and shorter length of stay (median: 5 days [IQR 4-7] vs. 6 days [IQR 5-13]; p = 0.049) compared with patients undergoing DPS. CONCLUSION: SPDP for pNET was associated with acceptable perioperative and long-term outcomes that were comparable to DPS. SPDP should be considered for patients with pNET.

Recurrence of Non-functional Pancreatic Neuroendocrine Tumors After Curative Resection: A Tumor Burden-Based Prediction Model.

BACKGROUND: Patients can experience recurrence following curative-intent resection of non-functional pancreatic neuroendocrine tumors (NF-pNETs). We sought to develop a nomogram to risk stratify patients relative to recurrence following resection of NF-pNETs. METHODS: Patients who underwent curative-intent resection for NF-pNETs between 1997 and 2016 were identified from a multi-institutional database. The impact of clinicopathologic factors, including tumor burden score (TBS) (TBS2 = (maximum tumor diameter)2 + (number of tumors)2), was assessed relative to recurrence-free survival (RFS), and a nomogram was developed and internally validated. RESULTS: With a median follow-up of 31.0 months (IQR 11.3-56.6 months), 66 (15.8%) out of 416 patients in the cohort experienced tumor recurrence. Overall, 3-, 5-, and 10-year RFS following curative-intent resection was 83.2%, 74.0%, and 44.7%, respectively. Several factors were associated with risk of recurrence including tumor grade (referent G1: G2, HR 4.07, 95% CI 2.29-7.26, p < 0.001; G3, HR 10.83, 95% CI 3.72-31.53, p < 0.001), lymph node metastasis (LNM) (HR 4.71, 95% CI 2.69-8.26, p < 0.001), as well as TBS (referent low: medium, HR 4.36, 95% CI 2.06-9.24, p < 0.001; high, HR 6.04, 95% CI 2.96-12.31, p < 0.001). A weighted nomogram including tumor grade (G1 0, G2 54.19, G3 100), LNM (N0 0, N1 42.06), and TBS (low 0, medium 44.07, high 56.48) was developed. The discriminatory power of the nomogram was very good with a C-index of 0.75 (95% CI, 0.66-0.79) in the training cohort and 0.71 (95% CI, 0.65-0.75) in the validation cohort. In addition, the nomogram performed better than the current 8th edition of AJCC TNM staging system, which had a C-index of 0.67 (95% CI, 0.60-0.73). CONCLUSIONS: A nomogram that incorporated tumor grade, LNM, and TBS was established that had good discrimination and calibration. The nomogram may be an effective tool to stratify patients relative to recurrence risk following resection of NF-pNETs.

Indications and outcomes of enucleation versus formal pancreatectomy for pancreatic neuroendocrine tumors.

BACKGROUND: Pancreatoduodenectomy (PD) or distal pancreatectomy (DP) are common procedures for patients with a pancreatic neuroendocrine tumor (pNET). Nevertheless, certain patients may benefit from a pancreas-preserving resection such as enucleation (EN). The aim of this study was to define the indications and differences in long-term outcomes among patients undergoing EN and PD/DP. METHODS: Patients undergoing resection of a pNET between 1992 and 2016 were identified. Indications and outcomes were evaluated, and propensity score matching (PSM) analysis was performed to compare long-term outcomes between patients who underwent EN versus PD/DP. RESULTS: Among 1034 patients, 143 (13.8%) underwent EN, 304 (29.4%) PD, and 587 (56.8%) DP. Indications for EN were small size (1.5 cm, IQR:1.0-1.9), functional tumors (58.0%) that were mainly insulinomas (51.7%). After PSM (n = 109 per group), incidence of postoperative pancreatic fistula (POPF) grade B/C was higher after EN (24.5%) compared with PD/DP (14.0%) (p = 0.049). Median recurrence-free survival (RFS) was comparable among patients who underwent EN (47 months, 95% CI:23-71) versus PD/DP (37 months, 95% CI: 33-47, p = 0.480). CONCLUSION: Comparable long-term outcomes were noted among patients who underwent EN versus PD/DP for pNET. The incidence of clinically significant POPF was higher after EN.

Primary Tumor Resection Offers Survival Benefit in Patients with Metastatic Midgut Neuroendocrine Tumors.

BACKGROUND: Approximately 35% of patients with midgut neuroendocrine tumors (MNET) present with distant metastases. Although successful resection of these metastatic foci improves overall survival (OS), the role of primary tumor resection (PTR) in patients with unresectable metastatic disease is unclear. The aim of this study is to evaluate prevalence and survival impact of PTR in patients with unresectable metastatic MNET. PATIENTS AND METHODS: A retrospective cohort study of patients with metastatic MNET was performed using the National Cancer Database (2004-2014). Demographic and clinicopathologic variables were compared between patients who did and did not undergo PTR. Survival analysis was performed using Kaplan-Meier and log-rank tests. Multivariable regression analysis was used to assess factors associated with PTR and all-cause mortality. RESULTS: The cohort included 4076 patients; 2520 (61.8%) underwent PTR. Patients more likely to undergo PTR were younger and diagnosed earlier, underwent treatment at a nonacademic facility, lived on the West Coast or in the Central USA, and presented with smaller lower-grade small bowel primary tumors. Median OS was improved for patients who underwent PTR compared with those who did not (71 vs. 29 months, p < 0.001). On multivariable analysis, younger age, Black race, higher income, later year of diagnosis, treatment at an academic facility, private insurance, fewer comorbidities, small bowel primary, lower grade, and PTR (hazard ratio 0.63, 95% confidence interval 0.51-0.78, p < 0.001) were associated with lower mortality. CONCLUSIONS: PTR was associated with improved OS. Further study is needed to understand how clinicians select patients for PTR.