Kenneth Cardona

Long-term survival of neonatal porcine islets in nonhuman primates by targeting costimulation pathways

We evaluated the ability of neonatal porcine islets to engraft and restore glucose control in pancreatectomized rhesus macaques. Although porcine islets transplanted into nonimmunosuppressed macaques were rapidly rejected by a process consistent with cellular rejection, recipients treated with a CD28-CD154 costimulation blockade regimen achieved sustained insulin independence (median survival, >140 days) without evidence of porcine endogenous retrovirus dissemination. Thus, neonatal porcine islets represent a promising solution to the crucial supply problem in clinical islet transplantation.

CD40‐Specific Costimulation Blockade Enhances Neonatal Porcine Islet Survival in Nonhuman Primates

The widespread clinical implementation of alloislet transplantation as therapy for type 1 diabetes has been hindered by the lack of suitable islet donors. Pig‐to‐human islet xenotransplantation is one strategy with potential to alleviate this shortage. Long‐term survival of porcine islets has been achieved using CD154‐specific antibodies to interrupt the CD40/CD154 costimulation pathway; however, CD154‐specific antibodies seem unlikely candidates for clinical translation. An alternative strategy for CD40/CD154 pathway interruption is use of CD40‐specific antibodies. Herein, we evaluate the ability of a chimeric CD40‐specific monoclonal antibody (Chi220) to protect islet xenografts. Neonatal porcine islets (∼50 000 IEQ/kg) were transplanted intraportally into pancreatectomized diabetic macaques. Immunosuppression consisted of induction therapy with Chi220 and the IL‐2 receptor‐specific antibody basiliximab, and maintenance therapy with sirolimus and the B7‐specific fusion protein belatacept. Chi220 effectively promoted xenoislet engraftment and survival, with five of six treated recipients achieving insulin‐independent normoglycemia (median rejection‐free survival 59 days; mean 90.8 days, maximum 203 days). No thromboembolic phenomena were observed. CD40 represents a promising alternative to CD154 as a therapeutic target, and the efficacy of CD40‐specific antibodies in islet xenotransplantation warrants further investigation.

Engraftment of adult porcine islet xenografts in diabetic nonhuman primates through targeting of costimulation pathways

Recent advances in human allogeneic islet transplantation have established β‐cell replacement therapy as a potentially viable treatment option for individuals afflicted with Type 1 diabetes. Two recent successes, one involving neonatal porcine islet xenografts transplanted into diabetic rhesus macaques treated with a costimulation blockade‐based regimen and the other involving diabetic cynomolgus monkeys transplanted with adult porcine islet xenografts treated with an alternative multidrug immunosuppressive regimen have demonstrated the feasibility of porcine islet xenotransplantation in nonhuman primate models. In the current study, we assessed whether transplantation of adult porcine islet xenografts into pancreatectomized macaques, under the cover of a costimulation blockade‐based immunosuppressive regimen (CD28 and CD154 blockade), could correct hyperglycemia. Our findings suggest that the adult porcine islets transplanted into rhesus macaques receiving a costimulation blockade‐based regimen are not uniformly subject to hyperacute rejection, can engraft (2/5 recipients), and have the potential to provide sustained normoglycemia. These results provide further evidence to suggest that porcine islet xenotransplantation may be an attainable strategy to alleviate the islet supply crisis that is one of the principal obstacles to large‐scale application of islet replacement therapy in the treatment of Type 1 diabetes.

CTLA4Ig Prevents Alloantibody Formation Following Nonhuman Primate Islet Transplantation Using the CD40-Specific Antibody 3A8

Islet transplantation to treat type 1 diabetes has been limited in part by toxicities of current immunosuppression and recipient humoral sensitization. Blockade of the CD28/CD80/86 and CD40/CD154 pathways has shown promise to remedy both these limitations, but translation has been hampered by difficulties in translating CD154‐directed therapies. Prior CD40‐directed regimens have led to prolonged islet survival, but fail to prevent humoral allosensitization. We therefore evaluated the addition of CTLA4Ig to a CD40 blockade‐based regimen in nonhuman primate (NHP) alloislet transplantation. Diabetic rhesus macaques were transplanted allogeneic islets using the CD40‐specific antibody 3A8, basiliximab induction, and sirolimus with or without CTLA4Ig maintenance therapy. Allograft survival was determined by fasting blood glucose levels and flow cytometric techniques were used to test for donor‐specific antibody (DSA) formation. CTLA4Ig plus 3A8, basiliximab and sirolimus was well tolerated and induced long‐term islet allograft survival. The addition of CTLA4Ig prevented DSA formation, but did not facilitate withdrawal of the 3A8‐based regimen. Thus, CTLA4Ig combines with a CD40‐specific regimen to prevent DSA formation in NHPs, and offers a potentially translatable calcineurin inhibitor‐free protocol inclusive of a single investigational agent for use in clinical islet transplantation without relying upon CD154 blockade.

The Surgical Management of Small Bowel Neuroendocrine Tumors: Consensus Guidelines of the North American Neuroendocrine Tumor Society

Abstract Small bowel neuroendocrine tumors (SBNETs) have been increasing in frequency over the past decades, and are now the most common type of small bowel tumor. Consequently, general surgeons and surgical oncologists are seeing more patients with SBNETs in their practices than ever before. The management of these patients is often complex, owing to their secretion of hormones, frequent presentation with advanced disease, and difficulties with making the diagnosis of SBNETs. Despite these issues, even patients with advanced disease can have long-term survival. There are a number of scenarios which commonly arise in SBNET patients where it is difficult to determine the optimal management from the published data. To address these challenges for clinicians, a consensus conference was held assembling experts in the field to review and discuss the available literature and patterns of practice pertaining to specific management issues. This paper summarizes the important elements from these studies and the recommendations of the group for these questions regarding the management of SBNET patients.

Effect of Preoperative Renal Insufficiency on Postoperative Outcomes after Pancreatic Resection: A Single Institution Experience of 1,061 Consecutive Patients

BACKGROUND Chronic kidney disease (CKD) is known to adversely affect cardiac and vascular surgery outcomes. We examined the effect of preoperative renal insufficiency on postoperative outcomes after pancreatic resection. STUDY DESIGN All patients who underwent pancreatic resection between January 2005 and July 2012 were identified. Glomerular filtration rate (eGFR) was estimated by the Modification of Diet in Renal Disease formula. Severe CKD (stages 4-5) was defined as eGFR < 30 mL/min/1.73 m(2). Renal function also was analyzed using serum creatinine (sCr) dichotomized at 1.8 mg/dL. Primary outcomes were any complication, major complications, and respiratory failure. Multivariate models for each endpoint were constructed by including all variables with p value ≤ 0.10 on univariate analysis. RESULTS There were 1,061 patients identified; 709 underwent pancreaticoduodenectomy, 307 distal pancreatectomy, and 45 central or total pancreatectomy. Median sCr value was 0.86 mg/dL (range 0.30 to 14.1 mg/dL). Eighteen patients (1.7%) had severe CKD and 31 (2.9%) had sCr ≥ 1.8 mg/dL. Complications occurred in 622 patients (58.6%), major complications in 198 (18.7%), and respiratory failure in 48 (4.5%). Both severe CKD and sCr ≥ 1.8 mg/dL were associated with any complication, major complications, and respiratory failure on univariate analysis. On multivariate analysis, severe CKD was associated with increased complications (odds ratio [OR] 5.5; 95% CI 1.3 to 25.5; p = 0.02) and respiratory failure (OR 6.1; 95% CI 1.8 to 20.5; p = 0.03), but not major complications. Using sCr ≥ 1.8 mg/dL as a surrogate marker for renal insufficiency, patients with sCr ≥ 1.8 mg/dL had increased risk of any complication (OR 3.5; 95% CI 1.3 to 9.3; p = 0.01), major complications (OR 2.2; 95% CI 1.04 to 4.8; p = 0.04), and respiratory failure (OR 4.7; 95% CI 1.8 to 12.6; p = 0.002). CONCLUSIONS Few patients with significant renal insufficiency are candidates for pancreatic resection. Severe CKD (stages 4-5) is associated with increased risk of complication and respiratory failure. Serum creatinine ≥ 1.8 mg/dL may serve as a useful marker of renal insufficiency and identifies patients at significantly increased risk of any complication, major complication, and respiratory failure after pancreatic resection.

HER2 in resected gastric cancer: Is there prognostic value?

The role of HER2 in patients with early stage/resected gastric cancer is controversial. This study investigates the prevalence and prognostic value of HER2 in patients undergoing curative intent resection for gastric adenocarcinoma.

Contemporary Management of Borderline Resectable and Locally Advanced Unresectable Pancreatic Cancer

UNLABELLED Adenocarcinoma of the pancreas remains a highly lethal disease, with less than 5% survival at 5 years. Borderline resectable pancreatic cancer (BRPC) and locally advanced unresectable pancreatic cancer (LAPC) account for approximately 30% of newly diagnosed cases of PC. The objective of BRPC therapy is to downstage the tumor to allow resection; the objective of LAPC therapy is to control disease and improve survival. There is no consensus on the definitions of BRPC and LAPC, which leads to major limitations in designing clinical trials and evaluating their results. A multimodality approach is always needed to ensure proper utilization and timing of chemotherapy, radiation, and surgery in the management of this disease. Combination chemotherapy regimens (5-fluorouracil, leucovorin, irinotecan, oxaliplatin, and gemcitabine [FOLFIRINOX] and gemcitabine/nab-paclitaxel) have improved overall survival in metastatic disease. The role of combination chemotherapy regimens in BRPC and LAPC is an area of active investigation. There is no consensus on the dose, modality, and role of radiation therapy in the treatment of BRPC and LAPC. This article reviews the literature and highlights the areas of controversy regarding management of BRPC and LAPC. IMPLICATIONS FOR PRACTICE Pancreatic cancer is one of the worst cancers with regard to survival, even at early stages of the disease. This review evaluates all the evidence for the stages in which the cancer is not primarily resectable with surgery, known as borderline resectable or locally advanced unresectable. Recently, advancements in radiation techniques and use of better combination chemotherapies have improved survival and tolerance. There is no consensus on description of stages or treatment sequences (chemotherapy, chemoradiation, radiation), nor on the best chemotherapy regimen. The evidence behind the treatment paradigm for these stages of pancreatic cancer is summarized.

Value of Primary Operative Drain Placement after Major Hepatectomy: A Multi-Institutional Analysis of 1,041 Patients

BACKGROUND The value of routine primary (intraoperative) drain placement after major hepatectomy remains unclear. We sought to determine if primary drainage led to decreased rates of complications, specifically, intra-abdominal biloma or infection requiring a secondary (postoperative) drainage procedure. STUDY DESIGN All patients who underwent major hepatectomy (≥3 hepatic segments) at 3 institutions, from 2000 to 2012, were identified. Patients with biliary anastomoses were excluded. Primary outcomes were any complication, rate of secondary drainage procedures, bile leak, and 30-day readmission. RESULTS There were 1,041 patients who underwent major hepatectomy without biliary anastomosis; 564 (54%) had primary drains placed at the surgeons discretion. Primary drain placement was associated with increased complications (56% vs 44%; p < 0.001), bile leaks (7.3% vs 4.2%; p = 0.048), and 30-day readmissions (16.4% vs 8.0%; p < 0.001), but was not associated with a decrease in secondary drainage procedures (8.0% vs 5.9%; p = 0.23). Patients with primary drains demonstrated higher American Society of Anesthesioloigsts (ASA) class, greater blood loss, more transfusions, and larger resections. After accounting for these significant clinicopathologic variables on multivariate analysis, primary drain placement was not associated with increased risk of any complications. Primary drainage was, however, independently associated with increased risk of bile leak (hazard ratio [HR] 2.04; 95% CI1.02 to 4.09; p = 0.044) and 30-day readmission (HR 1.79; 95% CI1.14 to 2.80; p = 0.011). There still was no reduction in the need for secondary drainage procedures (HR 0.98; p = 0.96). CONCLUSIONS Primary intraoperative drain placement after major hepatectomy does not decrease the need for secondary drainage procedures and may be associated with increased bile leaks and 30-day readmissions. Routine drain placement is not warranted.

Factors Associated With Recurrence and Survival in Lymph Node-negative Gastric Adenocarcinoma: A 7-Institution Study of the US Gastric Cancer Collaborative.

Objectives: To determine pathologic features associated with recurrence and survival in patients with lymph node–negative gastric adenocarcinoma. Study Design: Multi-institutional retrospective analysis. Background: Lymph node status is among the most important predictors of recurrence after gastrectomy for gastric adenocarcinoma. Pathologic features predictive of recurrence in patients with node-negative disease are less well established. Methods: Patients who underwent curative resection for gastric adenocarcinoma between 2000 and 2012 from 7 institutions of the US Gastric Cancer Collaborative were analyzed, excluding 30-day mortalities and stage IV disease. Competing risks regression and multivariate Cox regression were used to determine pathologic features associated with time to recurrence and overall survival. Differences in cumulative incidence of recurrence were assessed using the Gray method (for univariate nonparametric analyses) and the Fine and Gray method (for multivariate analyses) and shown as subhazard ratios (SHRs) and adjusted subhazard ratios (aSHRs), respectively. Results: Of 805 patients who met inclusion criteria, 317 (39%) had node-negative disease, of which 54 (17%) recurred. By 2 and 5 years, 66% and 88% of patients, respectively, experienced recurrence. On multivariate competing risks regression, only T-stage 3 or higher was associated with shorter time to recurrence [aSHR = 2.7; 95% confidence interval (CI), 1.5–5.2]. Multivariate Cox regression showed T-stage 3 or higher [hazard ratio (HR) = 1.8; 95% CI, 1.2–2.8], lymphovascular invasion (HR = 2.2; 95% CI, 1.4–3.4), and signet ring histology (HR = 2.1; 95% CI, 1.2–3.6) to be associated with decreased overall survival. Conclusions: Despite absence of lymph node involvement, patients with T-stage 3 or higher have a significantly shorter time to recurrence. These patients may benefit from more aggressive adjuvant therapy and postoperative surveillance regimens.