Prophylactic Cholecystectomy is Safe in Patients Undergoing Cytoreductive Surgery With Hyperthermic Intraperitoneal Chemotherapy.

BACKGROUND: While cholecystectomy is one of the most common operations performed in the United States, there is a continued debate regarding its prophylactic role in elective surgery. Particularly among patients with peritoneal carcinomatosis who undergo cytoreduction surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC), further abdominal operations may pose increasing morbidity due to intraabdominal adhesions and potential recurrence. This bi-institutional retrospective study aims to assess postoperative morbidity associated with prophylactic cholecystectomy at the time of CRS-HIPEC. METHODS: We performed a bi-institutional retrospective analysis of 578 patients who underwent CRS-HIPEC from 2011 to 2021. Postoperative outcomes among patients who underwent prophylactic cholecystectomy at the time of CRS-HIPEC were compared to patients who did not, particularly rate of bile leak, hospital length of stay, rate of Clavien-Dindo classification morbidity grade III or greater, and number of hospital re-admissions within 30 days. RESULTS: Of the 535 patients available for analysis, 206 patients (38.3%) underwent a prophylactic cholecystectomy. Of the 3 bile leaks (1.5%) that occurred among patients who underwent prophylactic cholecystectomy, all 3 occurred in patients who underwent a concomitant liver resection. There were no significant differences in hospital length of stay, postoperative morbidity, and number of hospital re-admissions among patients who underwent prophylactic cholecystectomy compared to those who did not. CONCLUSION: Prophylactic cholecystectomy in patients undergoing CRS-HIPEC is not associated with increased morbidity or increased bile leak risk compared to historical data. While the benefits of prophylactic cholecystectomy are not yet elucidated, it may be considered to avoid potential future morbid operations for biliary disease.

Preoperative anemia: impact on short- and long-term outcomes following curative-intent resection of gastroenteropancreatic neuroendocrine tumors.

BACKGROUND: The effect of preoperative anemia on clinical outcomes of patients undergoing resection of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) has not been previously investigated. This study aimed to characterize how preoperative anemia affected short- and long-term outcomes of patients undergoing curative-intent resection of GEP-NETs. METHODS: Patients who underwent curative-intent resection for GEP-NETs between January 1990 and December 2020 were identified from 8 major institutions. The last preoperative hemoglobin level was recorded; anemia was defined as <13.5 g/dL in males or <12.0 g/dL in females based on the guides of the American Society of Hematology. The effect of anemia on postoperative outcomes was assessed on uni- and multivariate analyses. RESULTS: Among 1559 patients, the median age was 58 years (IQR, 48-66), and roughly one-half of the cohort was male (796 [51.1%]). Most patients had a pancreatic tumor (1040 [66.7%]), followed by small bowel (259 [16.6%]), duodenum (103 [6.6%]), stomach (66 [4.2%]), appendix (53 [3.4%]), and other locations (38 [2.6%]). The median preoperative hemoglobin level was 13.4 g/dL (IQR, 12.2-14.5). Overall, 101 (6.7%) and 119 (8.5%) patients received an intra- or postoperative packed red blood cell (pRBC) transfusion, respectively. A total of 972 patients (44.5%) experienced a postoperative complication. Although the overall incidence of complications was no different among patients who did (anemic: 48.7%) vs patients who did not (nonanemic: 47.3%) have anemia (P = .597), patients with preoperative anemia were more likely to develop a major (Clavien-Dindo grade ≥IIIa: 48.9% [anemic] vs 38.0% [nonanemic]; P = .006) and multiple (≥3 types of complications: 32.2% [anemic] vs 19.7% [anemic]; P < .001) complications. Of note, 1-, 3-, and 5-year overall survival (OS) rates were 96.7%, 90.5%, and 86.6%, respectively. On multivariable analysis, anemia (hazard ratio, 2.0; 95% CI, 1.2-3.2; P = .006) remained associated with worse OS; postoperative pRBC transfusion was associated with an OS (5-year OS: 75.0% vs 87.7%; P = .017) and recurrence-free survival (RFS; 5-year RFS: 66.9% vs 76.5%; P = .047). CONCLUSION: Preoperative anemia was commonly identified in roughly 1 in 3 patients who underwent curative-intent resection for GEP-NETs. Preoperative anemia was strongly associated with a higher risk of postoperative morbidity and worse long-term outcomes.

Survival disparities in rural versus urban patients with pancreatic neuroendocrine tumor: A multi-institutional study from the US neuroendocrine tumor study group.

BACKGROUND: Pancreatic Neuroendocrine Tumors (PNETs) are indolent malignancies that often have a prolonged clinical course. This study assesses disparities in outcomes between PNET patients who live in urban (UA) and rural areas (RA). METHODS: A retrospective cohort study was performed using the US Neuroendocrine Tumor Study Group database. PNET patients with a home zip code recorded were included and categorized as RA or UA according to the Federal Office of Rural Health Policy. Overall survival (OS) was analyzed by Kaplan-Meier method, log-rank test, and logistical regression. RESULTS: Of the 1176 PNET patients in the database, 1126 (96%) had zip code recorded. While 837 (74%) lived in UA, 289 (26%) lived in RA. RA patients had significantly shorter median OS following primary PNET resection (122 vs 149 months, p â€‹= â€‹0.01). After controlling for income, local healthcare access, distance from treatment center, ASA class, BMI, and T/N/M stage, living in a RA remained significantly associated with worse OS (HR 1.60, 95%CI 1.08-2.39, p â€‹= â€‹0.02). CONCLUSION: Rural patients have significantly shorter OS following PNET resection compared to their urban counterparts.

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.

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.

Effects of Specialist Palliative Care for Patients Undergoing Major Abdominal Surgery for Cancer: A Randomized Clinical Trial.

Importance: Specialist palliative care benefits patients undergoing medical treatment of cancer; however, data are lacking on whether patients undergoing surgery for cancer similarly benefit from specialist palliative care. Objective: To determine the effect of a specialist palliative care intervention on patients undergoing surgery for cure or durable control of cancer. Design, Setting, and Participants: This was a single-center randomized clinical trial conducted from March 1, 2018, to October 28, 2021. Patients scheduled for specified intra-abdominal cancer operations were recruited from an academic urban referral center in the Southeastern US. Intervention: Preoperative consultation with palliative care specialists and postoperative inpatient and outpatient palliative care follow-up for 90 days. Main Outcomes and Measures: The prespecified primary end point was physical and functional quality of life (QoL) at postoperative day (POD) 90, measured by the Functional Assessment of Cancer Therapy-General (FACT-G) Trial Outcome Index (TOI), which is scored on a range of 0 to 56 with higher scores representing higher physical and functional QoL. Prespecified secondary end points included overall QoL at POD 90 measured by FACT-G, days alive at home until POD 90, and 1-year overall survival. Multivariable proportional odds logistic regression and Cox proportional hazards regression models were used to test the hypothesis that the intervention improved each of these end points relative to usual care in an intention-to-treat analysis. Results: A total of 235 eligible patients (median [IQR] age, 65.0 [56.8-71.1] years; 141 male [60.0%]) were randomly assigned to the intervention or usual care group in a 1:1 ratio. Specialist palliative care was received by 114 patients (97%) in the intervention group and 1 patient (1%) in the usual care group. Adjusted median scores on the FACT-G TOI measure of physical and functional QoL did not differ between groups (intervention score, 46.77; 95% CI, 44.18-49.04; usual care score, 46.23; 95% CI, 43.08-48.14; P = .46). Intervention vs usual care group odds ratio (OR) was 1.17 (95% CI, 0.77-1.80). Palliative care did not improve overall QoL measured by the FACT-G score (intervention vs usual care OR, 1.09; 95% CI, 0.75-1.58), days alive at home (OR, 0.87; 95% CI, 0.69-1.11), or 1-year overall survival (hazard ratio, 0.97; 95% CI, 0.50-1.88). Conclusions and Relevance: This randomized clinical trial showed no evidence that early specialist palliative care improves the QoL of patients undergoing nonpalliative cancer operations. Trial Registration: ClinicalTrials.gov Identifier: NCT03436290.

Distribution and Surgical Management of Visceral Ewing Sarcoma Among Children and Adolescents.

INTRODUCTION: Ewing sarcoma (EWS) is a highly malignant tumor of bone and soft tissue that occasionally arises from viscera. Visceral EWS (V-EWS) is challenging to manage given its varied organ distribution and often late-stage presentation. We aimed to characterize our institutional experience with V-EWS, focusing on its surgical management, and to compare V-EWS outcomes against those with osseous (O-EWS) and soft tissue EWS (ST-EWS). METHODS: Retrospective review of all EWS patients ≤21 years presenting to a single institution between 2000 and 2022. Patient- and disease-specific characteristics were compared. Overall and relapse-free survival were estimated using Kaplan Meier methods and log-rank test. RESULTS: 156 EWS patients were identified: 117 O-EWS, 20 ST-EWS, and 19 V-EWS. V-EWS arose in the kidney (n = 5), lung (n = 5), intestine (n = 2), esophagus (n = 1), liver (n = 1), pancreas (n = 1), adrenal gland (n = 1), vagina (n = 1), brain (n = 1), and spinal cord (n = 1). No significant demographic differences were detected between EWS groups. V-EWS was more frequently metastatic at presentation (63.2%; p = 0.005), yet no significant overall or relapse-free survival differences emerged between EWS groups, with similar follow-up intervals. While V-EWS required multiple unique operative strategies to gain primary control, no significant difference in treatment strategies appeared between groups. Surgery-only primary control was associated with improved overall and relapse-free survival in all groups. CONCLUSIONS: V-EWS presents unique management challenges in children and adolescents given its variable sites of origin. This large cohort is the first to describe the surgical management and outcomes of V-EWS, demonstrating more frequent metastatic presentation, while achieving similar survival across groups. LEVEL OF EVIDENCE: Level 2 - Cohort Study.

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.

Safety and Clinical Value of Prophylactic Ureteral Stenting Before Cytoreductive Surgery With Hyperthermic Intraperitoneal Chemotherapy.

BACKGROUND: Prophylactic ureteral stents (PUS) are typically placed prior to complex abdominal or pelvic operations at the surgeon's discretion to help facilitate detection of iatrogenic ureteral injury. However, its usefulness and safety in the setting of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) have not been examined. This study aims to evaluate the potential clinical value and risk profile of prophylactic ureteral stent placement prior to CRS-HIPEC. METHODS: We performed a single-institutional retrospective analysis of 145 patients who underwent CRS-HIPEC from 2013 to 2021. Demographic and operative characteristics were compared between patients who underwent PUS placement and those that did not. Ureteral stent-related complications were evaluated. RESULTS: Of the 145 patients included in the analysis, 124 underwent PUS placement. There were no significant differences in patient demographics, medical comorbidities, or tumor characteristics. Additionally, PUS placement did not significantly increase operative time and was not associated with increased pelvic organ resection. However, patients who underwent prophylactic ureteral stenting had significantly higher peritoneal carcinomatosis index score (15.1 vs 9.1, P=.002) and increased rate of ureteral complications (24.2% vs 14.3%, P=.04), which led to lengthened hospital stay (13.2 days vs 8.1 days, P= .03). Notably, the sole ureteral injury and three cases of hydronephrosis were seen in patients who underwent PUS. CONCLUSION: Prophylactic ureteral stent placement in patients undergoing CRS-HIPEC may be useful, particularly in patients with predetermined extensive pelvic disease. However, PUS placement is not without potential morbidity and should be selectively considered in patients for whom benefits outweigh the risks.

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.

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.

Immunostimulatory Cancer-Associated Fibroblast Subpopulations Can Predict Immunotherapy Response in Head and Neck Cancer.

PURPOSE: Cancer-associated fibroblasts (CAF) have been implicated as potential mediators of checkpoint immunotherapy response. However, the extensive heterogeneity of these cells has precluded rigorous understanding of their immunoregulatory role in the tumor microenvironment. EXPERIMENTAL DESIGN: We performed high-dimensional single-cell RNA sequencing (scRNA-seq) on four patient tumors pretreatment and posttreatment from a neoadjuvant trial of patients with advanced-stage head and neck squamous cell carcinoma that were treated with the αPD-1 therapy, nivolumab. The head and neck CAF (HNCAF) protein activity profiles, derived from this cohort of paired scRNA-seq, were used to perform protein activity enrichment analysis on the 28-patient parental cohort of clinically annotated bulk transcriptomic profiles. Ex vivo coculture assays were used to test functional relevance of HNCAF subtypes. RESULTS: Fourteen distinct cell types were identified with the fibroblast population showing significant changes in abundance following nivolumab treatment. Among the fibroblast subtypes, HNCAF-0/3 emerged as predictive of nivolumab response, while HNCAF-1 was associated with immunosuppression. Functionally, HNCAF-0/3 were found to reduce TGFß-dependent PD-1+TIM-3+ exhaustion of CD8 T cells, increase CD103+NKG2A+ resident memory phenotypes, and enhance the overall cytolytic profile of T cells. CONCLUSIONS: Our findings demonstrate the functional importance of distinct HNCAF subsets in modulating the immunoregulatory milieu of human HNSCC. In addition, we have identified clinically actionable HNCAF subtypes that can be used as a biomarker of response and resistance in future clinical trials.

Stapled Full-Thickness Diaphragm Resection: A Novel Approach to Diaphragmatic Resection in Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy.

Full-thickness diaphragm resection (FT-DR) during cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is sometimes required to achieve a complete cytoreduction. It is conventionally performed with electrocautery with primary repair or mesh repair. FT-DR using a linear cutting stapler is a novel technique that avoids entry to the chest cavity and minimizes the use of electrocautery on the diaphragm. We performed an institutional retrospective review of a prospectively maintained database of 145 patients who underwent CRS-HIPEC between 2013 and 2019. Patients were divided into the Conventional or Stapled group based on the FT-DR approach indicated in the operative report. Of the 145 patients who underwent CRS-HIPEC, 27 underwent FT-DR, with 63% (n = 17) in the Stapled group. There were no significant demographic or oncologic differences between the 2 groups. Patients in the Stapled group underwent tube thoracostomy (13.3% vs 60%; p = 0.008), were diagnosed with pneumonia (12% vs 50%; p = 0.04), required reintubation (6% vs 40%; p = 0.03), and required mechanical ventilation more than 48 hours (6% vs 50%; p = 0.02) less frequently than the Conventional group. There was no difference in pleural recurrence between the 2 groups (Conventional 20% vs Stapled 12%, p = 0.56). Stapled full-thickness diaphragm resection is a novel approach to achieving a complete cytoreduction that excludes the pleural cavity, minimizes diaphragm manipulation, and is associated with improved postoperative pulmonary outcomes in patients undergoing CRS-HIPEC.