Phosphoprotein-based biomarkers as predictors for cancer therapy.

Disparities in cancer patient responses have prompted widespread searches to identify differences in sensitive vs. nonsensitive populations and form the basis of personalized medicine. This customized approach is dependent upon the development of pathway-specific therapeutics in conjunction with biomarkers that predict patient responses. Here, we show that Cdk5 drives growth in subgroups of patients with multiple types of neuroendocrine neoplasms. Phosphoproteomics and high throughput screening identified phosphorylation sites downstream of Cdk5. These phosphorylation events serve as biomarkers and effectively pinpoint Cdk5-driven tumors. Toward achieving targeted therapy, we demonstrate that mouse models of neuroendocrine cancer are responsive to selective Cdk5 inhibitors and biomimetic nanoparticles are effective vehicles for enhanced tumor targeting and reduction of drug toxicity. Finally, we show that biomarkers of Cdk5-dependent tumors effectively predict response to anti-Cdk5 therapy in patient-derived xenografts. Thus, a phosphoprotein-based diagnostic assay combined with Cdk5-targeted therapy is a rational treatment approach for neuroendocrine malignancies.

Management of Appendiceal Neuroendocrine Tumors: Metastatic Potential of Small Tumors.

BACKGROUND: Appendiceal neuroendocrine tumors (ANETs) are rare neoplasms usually discovered incidentally during appendectomy. ANETs < 2 cm were thought to have no metastatic potential, and this dogma has driven management. Our aim is to evaluate the metastatic potential of ANETs < 2 cm. PATIENTS AND METHODS: A retrospective review was performed in a series of patients with ANETs who presented to our tertiary referral center from 1998 to 2019. Demographics, tumor characteristics, treatment, and clinical outcomes were evaluated. RESULTS: In total, 114 patients were included. Median follow-up was 3.3 years (range, 21 days-15 years). At last follow-up, 34 (30%) patients had positive regional lymph nodes and 20 (18%) patients had metastatic disease. Of the 20 patients with metastatic disease, 11 (55%) had primary ANETs < 2 cm. Patient age > 40 years at diagnosis and ANETs with serosal invasion, lymphovascular invasion, intermediate tumor grade, or positive lymph nodes were features significantly more likely to present with metastatic disease. We found no difference in the rate of lymph node positivity, metastatic disease, or overall survival when patients were stratified by tumor size or type of resection (appendectomy vs. right hemicolectomy). On multivariate analysis, patients with metastatic disease at diagnosis had worse overall survival (HR = 24.4, p = 0.008). CONCLUSIONS: In our cohort, tumor size was not a significant risk factor for metastatic disease or worse outcome as many patients with ANETs < 2 cm developed metastatic disease. Appendectomy alone was sufficient surgical management for most ANETs. Patients with risk factors for metastatic disease, regardless of primary ANET size, should be evaluated thoroughly and counseled for further management and surveillance.

Current Treatment Options in Gastroenteropancreatic Neuroendocrine Carcinoma.

Poorly differentiated gastroenteropancreatic neuroendocrine carcinomas (GEPNECs) are a rare neoplasm with a bleak prognosis. Currently there are little prospective data available for optimal treatment. This review discusses the current available regimens and the future direction for the treatment of GEPNECs. Treatment plans for GEPNECs are often adapted from those devised for small cell lung cancer; however, differences in these malignancies exist, and GEPNECs require their own treatment paradigms. As such, current first-line treatment for GEPNECs is platinum-based chemotherapy with etoposide. Studies show that response rate and overall survival remain comparable between cisplatin and carboplatin versus etoposide and irinotecan; however, prognosis remains poor, and more efficacious therapy is needed to treat this malignancy. Additional first-line and second-line treatment options beyond platinum-based chemotherapy have also been investigated and may offer further treatment options, but again with suboptimal outcomes. Recent U.S. Food and Drug Administration approval of peptide receptor radionuclide therapy in low- and intermediate-grade neuroendocrine tumors may open the door for further research in its usefulness in GEPNECs. Additionally, the availability of checkpoint inhibitors lends promise to the treatment of GEPNECs. This review highlights the lack of large, prospective studies that focus on the treatment of GEPNECs. There is a need for randomized control trials to elucidate optimal treatment regimens specific to this malignancy. IMPLICATIONS FOR PRACTICE: There are limited data available for the treatment of poorly differentiated gastroenteropancreatic neuroendocrine carcinomas (GEPNECs) because of the rarity of this malignancy. Much of the treatment regimens used in practice today come from research in small cell lung cancer. Given the poor prognosis of GEPNECs, it is necessary to have treatment paradigms specific to this malignancy. The aim of this literature review is to summarize the available first- and second-line GEPNEC therapy, outline future treatments, and highlight the vast gap in the literature.

The Role of Capecitabine/Temozolomide in Metastatic Neuroendocrine Tumors.

BACKGROUND: Neuroendocrine tumors (NETs) are commonly treated with multimodality therapy. The combination of capecitabine and temozolomide (CAPTEM) has been suggested as a treatment option for patients with metastatic NETs. We present our experience with CAPTEM. METHODS: Data on NET patients who were placed on CAPTEM and received at least one cycle were obtained from a Velos eResearch database. Response rate was calculated by RECIST 1.1. Overall survival and progression-free survival (PFS) were calculated by the Kaplan-Meier survival method. RESULTS: A total of 29 patients (17 male and 12 female) were included. Median age at CAPTEM initiation was 58 years (range: 26-77). Primary tumors included 9 small bowel (31%), 15 pancreas (52%), 3 lung (10%), and 2 rectum (7%). Median number of CAPTEM cycles was 8 (range: 1-55). Partial response occurred in 5 patients (5 of 29, 17%); 14 patients (14 of 29, 48%) had stable disease, and 10 patients (10 of 29, 34%) had progressive disease. A total of 3 (20%) and 5 (33%) pancreatic NETs experienced partial response and stable disease, respectively. A total of 2 (14%) and 9 (64%) nonpancreatic NETs experienced partial response and stable disease, respectively. Partial response was noted in 1 patient (13%) and stable disease in 5 patients (63%) with Ki-67 values of less than 2%. In patients with Ki-67 values of 2%-20%, partial response was noted in 3 (19%) and stable disease in 8 (50%). Partial response and stable disease were noted in 1 patient each (20%) with Ki-67 values greater than 20%. Median PFS was 12 months. Adverse reactions caused dose reductions in 24% of patients. CONCLUSION: Although adverse reactions were experienced, most patients tolerated this regimen. CAPTEM should be considered as a reasonable treatment option for metastatic NET patients. IMPLICATIONS FOR PRACTICE: The role of chemotherapy in neuroendocrine tumors has evolved in recent years. The results of this study suggest that the combination of capecitabine and temozolomide provides an adequate treatment option and may prolong survival in patients with a wide variety of metastatic neuroendocrine tumors. Although prospective data are needed, this research adds to the abundance of retrospective experience with this combination that appears to show that capecitabine and temozolomide could potentially be an option for patients with advanced neuroendocrine tumors who have progressed on standard treatment.

Novel synthesis of various orthogonally protected Cα-methyllysine analogues and biological evaluation of a vapreotide analogue containing (S)-α-methyllysine.

Prochiral malonic diesters containing a quaternary carbon center have been successfully transformed into a diverse set of (t)Boc-Fmoc-α(2,2)-methyllysine-OH analogues through chiral malonic half-ester intermediates obtained via enzymatic (Pig Liver Esterase, PLE) hydrolysis. The variety of chiral half-ester intermediates, which vary from 1 to 6 methylene units in the side chain, are achieved in moderate to high optical purity and in good yields. The PLE hydrolysis of malonic diesters with various side chain lengths appears to obey the Jones's PLE model according to the stereochemical configurations of the resulting chiral half-esters. The established synthetic strategy allows the construction of both enantiomers of α(2,2)-methyllysine analogues, and a (S)-ß(2,2)-methyllysine analogue from a common synthon by straightforward manipulation of protecting groups. Two different straightforward and cost effective synthetic strategies are described for the synthesis of α(2,2)-methyllysine analogues. The described strategies should find significant usefulness in preparing novel peptide libraries with unnatural lysine analogues. A Vapreotide analogue incorporating (S)-α(2,2)-methyllysine was prepared. However, the Vapreotide analogue with (S)-α-methyl-α-lysine is found to lose its specific binding to somatostatin receptor subtype 2 (SSTR2).

Do primary neuroendocrine tumors and metastasis have the same characteristics?

BACKGROUND: Only one tumor site is usually biopsied to determine the histologic features of that patient's entire tumor burden. We hypothesized that there are significant histologic and functional differences in primary neuroendocrine tumors (NETS) and their nodal or organ metastases. We also hypothesized that limited tumor sampling could lead to erroneous assumptions about the tumor's histologic characteristics and clinical behavior. MATERIALS AND METHODS: Thirteen patients with metastatic well differentiated midgut NETS underwent simultaneous removal of their primary tumor, nodal metastasis, and organ metastasis. Each tumor site was stained quantitatively for Ki-67, chromogranin A (CGA), synaptophysin, CD31, and Factor VIII. Samples were also evaluated with in vitro tumor angiogenesis and drug chemoresistance assays. RESULTS: Ki-67 staining was nearly identical at all sites tested. Quantitative stains for CGA, synaptophysin, cluster of differentiation 31 (CD31), and Factor VIII varied considerably among the patient's three tissue site samples. Only 6% of the tissue samples tested against a battery of chemotherapeutic agents exhibited susceptibility to a single drug at all three tumor sites. In contrast, several antiangiogenic agents exhibited uniform effectiveness across all three tissue sites in multiple patients. CONCLUSIONS: Sampling only one NET tumor site may lead to erroneous assumptions about the tumor's histologic features and functional behavior. Evaluation of primary tumors and their nodal and organ metastasis may be necessary to optimize clinical decision making.

Metronomic dosing enhances the anti-angiogenic effect of epothilone B.

BACKGROUND: High doses (10 nM) of epothilone B, a microtubule stabilizer, will inhibit the development of human tumor-derived angiogenesis following short (14 d) drug exposure times. Metronomic dosing regimes use lower drug doses and prolonged drug exposure times in an attempt to decrease toxicity compared with standard dosing schedules. We hypothesized that epothilone B would be an effective anti-angiogenic agent when administered at very low doses over an extended period of time. METHODS: Fragments of four fresh human tumors were cultured in a fibrin-thrombin matrix and maintained in nutrient media plus 20% fetal bovine serum (FBS) for 56 d. Tumor fragments (n=40-60 per group) were exposed to weekly doses of epothilone B at concentrations of 10, 5, 1, 0.5, or 0.1 nM. All of these concentrations are clinically achievable. Tumor angiogenesis was assessed weekly on d 14-56 using a validated visual grading system. This system rates neovessel growth, density, and length on a 0-16 scale [angiogenic index, (AI)]. The average change in AI between d 14 and 56 was calculated for all samples and used to evaluate the metronomic response. RESULTS: Epothilone B produced a dose-dependent anti-angiogenic response in all tumors. Two of the four tumors demonstrated a clear and significant metronomic anti-angiogenic effect over time. CONCLUSIONS: Epothilone B, when dosed by a metronomic schedule may have a significant anti-angiogenic effect on human solid tumors. This study provides evidence for the potential use of epothilone B on a metronomic dosing schedule.

Cdk5 drives formation of heterogeneous pancreatic neuroendocrine tumors.

Pancreatic neuroendocrine tumors (PanNETs) are a heterogeneous population of neoplasms that arise from hormone-secreting islet cells of the pancreas and have increased markedly in incidence over the past four decades. Non-functional PanNETs, which occur more frequently than hormone-secreting tumors, are often not diagnosed until later stages of tumor development and have poorer prognoses. Development of successful therapeutics for PanNETs has been slow, partially due to a lack of diverse animal models for pre-clinical testing. Here, we report development of an inducible, conditional mouse model of PanNETs by using a bi-transgenic system for regulated expression of the aberrant activator of Cdk5, p25, specifically in ß-islet cells. This model produces a heterogeneous population of PanNETs that includes a subgroup of well-differentiated, non-functional tumors. Production of these tumors demonstrates the causative potential of aberrantly active Cdk5 for generation of PanNETs. Further, we show that human PanNETs express Cdk5 pathway components, are dependent on Cdk5 for growth, and share genetic and transcriptional overlap with the INS-p25OE model. The utility of this model is enhanced by the ability to form tumor-derived allografts. This new model of PanNETs will facilitate molecular delineation of Cdk5-dependent PanNETs and the development of new targeted therapeutics.

The role of VEGF pathways in human physiologic and pathologic angiogenesis.

BACKGROUND: In preclinical models, VEGF is a potent stimulant of both physiologic and pathologic angiogenesis. Conversely, anti-VEGF regimens have successfully inhibited angiogenesis both in vitro and in vivo. We hypothesized that VEGF would stimulate both physiologic and pathologic angiogenesis in a human-based fibrin-thrombin clot angiogenesis assay. We further speculated that anti-VEGF regimens would inhibit angiogenesis in this assay. METHODS: To test these hypotheses, discs of human placental veins (physiologic model) and fragments of human tumors (pathologic model) were embedded in fibrin-thrombin clots and treated with either VEGF-A165 (VEGF) or anti-VEGF pathway reagents including bevacizumab, IMC-18F1, IMC-1121, and PTK787 (n=30 wells per treatment group, multiple concentrations tested in each specimen). Angiogenic responses were assessed visually using a previously validated grading scheme. The percent of tissue explants that developed angiogenic invasion into the clot (% I) as well as the extent of angiogenic growth (AI) via a semi-quantitative scale were assessed at set intervals. RESULTS: VEGF failed to stimulate angiogenesis in both the physiologic and the pathologic model. While anti-VEGF reagents that targeted only one element of the VEGF pathway failed to consistently inhibit angiogenesis, PTK787, a receptor tyrosine kinase inhibitor that targets multiple VEGF and non-VEGF receptors, profoundly inhibited both physiologic and pathologic angiogenesis. CONCLUSION: These results suggest that VEGF-related pathways may not be solely responsible for stimulating angiogenesis in humans. Targeting the VEGF pathway in combination with elements of other growth factor pathways may provide a more effective means of inhibiting angiogenesis than targeting VEGF alone.

Resolution of pulsatile tinnitus following an upper mediastinal lymph node resection.

External compression of extracranial/mediastinal vessels has not been reported as an etiology of pulsatile tinnitus. We present a case in which compression of extracranial vasculature led to long term pulsatile tinnitus which resolved completely with surgical resection of metastatic lymph nodes. This should be included in the list of differential diagnoses when dealing with any patient with a complaint of pulsatile tinnitus. Patients with advanced carcinoid cancer often present with distant metastases to their left superior mediastinum and supraclavicular lymph node chain. We believe a careful search for nodal metastases compressing vascular structures in such patients is warranted as debilitating pulsatile tinnitus may be cured by a simple surgical procedure.

Outcomes of Capecitabine and Temozolomide (CAPTEM) in Advanced Neuroendocrine Neoplasms (NENs).

Capecitabine and temozolomide (CAPTEM) have shown promising results in the treatment of neuroendocrine neoplasms (NEN). The aim of this study was to evaluate the outcome and role for CAPTEM in malignant neuroendocrine neoplasms. Data were obtained from NEN patients who received at least one cycle of CAPTEM between November 2010 and June 2018. The average number of cycles was 9.5. For analysis, 116 patients were included, of which 105 patients (91%) underwent prior treatment. Median progression free survival (PFS) and overall survival (OS) were 13 and 38 months, respectively. Overall response rate (ORR) was 21%. Disease control rate (DCR) was 73% in all patients. PFS, median OS, ORR, and DCR for pancreatic NENs (pNEN) vs. non-pNEN was 29 vs. 11 months, 35 vs. 38 months, 38% vs. 9%, and 77% vs. 71%, respectively. Patients with pNEN had a 50% lower hazard of disease progression compared to those with non-pNEN (adjusted Hazard Ratio: 0.498, p = 0.0100). A significant difference in PFS was found between Ki-67 < 3%, Ki-67 3-20%, Ki-67 > 20-54%, and Ki-67 ≥ 55% (29 vs. 12 vs. 7 vs. 5 months; p = 0.0287). Adverse events occurred in 74 patients (64%). Our results indicate that CAPTEM is associated with encouraging PFS, OS, and ORR data in patients with NENs.

In vitro chemoresistance testing in well-differentiated carcinoid tumors.

BACKGROUND: Well-differentiated, "typical" carcinoid tumors traditionally have a very poor response to chemotherapy. We hypothesized that tumor specimens from well-differentiated carcinoid tumors would be highly resistant to the effects of chemotherapy when tested against a variety of antineoplastic agents in vitro. METHODS: Ninety-eight typical carcinoid specimens were surgically harvested, cultured, and tested against antineoplastics in vitro. (3)H-Thymidine incorporation was used to assess the percentage of cell-growth inhibition (PCI) of tested specimens. PCI was used to determine if specimens had extreme drug resistance (EDR), intermediate drug resistance (IDR), or low drug resistance (LDR) to each reagent against which they were tested. RESULTS: Seventy specimens generated results. Each was tested with an average of six drugs. The mean proportions of drugs classified as LDR, IDR, and EDR were 0.48 (range 0-1), 0.34 (range 0-1), and 0.18 (range 0-0.80), respectively. The mean numbers of drugs per specimen exhibiting LDR, IDR, and EDR chemoresistance were 2.7, 2.1, and 1.2, respectively. 57 of 70 specimens (81%) had LDR to at least two drugs. 5-FU had the highest frequency of low chemoresistance at 69%, followed by doxorubicin at 67%. Low in vitro resistance to chemotherapeutics was prevalent among typical carcinoids, while EDR was comparatively infrequent. CONCLUSIONS: This implies that there may be less clinical chemoresistance and more chemosensitivity among typical carcinoid tumors than clinical trials have previously revealed. These findings warrant additional investigations assessing the response of carcinoid tumors to assay-guided chemotherapy regimens.

Plasma Pancreastatin Predicts the Outcome of Surgical Cytoreduction in Neuroendocrine Tumors of the Small Bowel.

OBJECTIVES: Elevated pancreastatin (PST) levels have been shown to be associated with poor prognosis in small bowel neuroendocrine tumors (NETs). We hypothesized that plasma PST levels that remain elevated following surgical cytoreduction portend a poor prognosis in well-differentiated small bowel NETs. METHODS: Patients diagnosed with small bowel NETs who underwent surgical cytoreduction at our institution were identified. Demographics, histopathologic characteristics, and biochemical data were collected. Only patients who had serial preoperative PST (PreopPST) and postoperative PST (PostopPST) levels were included in this study. Patients were sorted into groups by PST level to assess their response to surgical cytoreduction (group 1, PreopPST/PostopPST normal; group 2, PreopPST elevated/PostopPST normal; group 3, PreopPST/PostopPST elevated). Survival rates were calculated from the date of surgery. RESULTS: PreopPST and PostopPST levels were collected from 300 patients. Patients in groups 1 (n = 74) and 2 (n = 81) had a significant survival advantage compared with patients in group 3 (n = 145) (P < 0.0001). Kaplan-Meier 5- and 10-year survival rates were as follows: group 1: 93% and 82%; group 2: 91% and 65%; and group 3: 58% and 34%, respectively. CONCLUSIONS: Serial monitoring of plasma PST is useful in predicting long-term survival following surgical cytoreduction and can be helpful to identify patients who have a poor prognosis.

Does the addition of adjuvant intraoperative tumor bed chemotherapy during midgut neuroendocrine tumor debulking procedures benefit patients?

BACKGROUND: Midgut neuroendocrine tumor (NET) patients are often diagnosed at advanced stages with extensive mesenteric nodal and hepatic metastasis. The only potentially curative treatment is surgical tumor eradication. Despite an aggressive resection, macro and microscopic residual disease still may remain in the resection bed. We hypothesize that the application of 5-fluorouracil (5-FU) within the tumor bed will help eliminate microscopic residual disease. METHODS: Records of 189 patients who underwent extensive cytoreductive surgeries during 2003-2012 for advanced, midgut NETs with extensive mesenteric lymphadenopathy were reviewed. Eighty-six patients (46%) who had 5-FU saturated gel foam strips secured into their mesenteric resection sites served as the study group and a matching 103 patients (54%) who did not have such an intra-operative chemotherapy served as controls. Survival from the time of diagnosis and post-operative complications between the two groups were compared. RESULTS: Mortality rates at 30, 60 and 90 days post-operatively were 4%, 0%, 0% versus 2%, 0%, 2% for study and control groups, respectively. Major complications (Grades III & IV) at the same intervals were 0, 0, 1 versus 2, 3, 2 for study and control groups, respectively. Median survival was 236 months versus 148 months for the study and control groups, respectively 24 (P=0.15). CONCLUSIONS: Intraoperative tumor resection bed chemotherapy is a safe adjuvant without discernible toxicity. This procedure may provide survival benefits to midgut NET patients with extensive mesenteric lymphadenopathy undergoing extensive cytoreductive surgery. Further study in prospective trials must be conducted to determine definitive benefit to the NET patient.

A novel assay to assess the effectiveness of antiangiogenic drugs in human breast cancer.

BACKGROUND: Many cytotoxic drugs maintain antiangiogenic properties, but there are no human, tumor-based assays to evaluate their antiangiogenic potential. We used a fibrin-thrombin clot-based angiogenesis model to evaluate the angiogenic response of human breast cancer to various cytotoxic agents commonly used in its treatment. METHODS: Fragments of freshly harvested human breast tumors were embedded in fibrin-thrombin clots and treated with five drugs: adriamycin, taxol, 5-fluorouracil (5-FU), methotrexate, and vincristine. Each treatment group included a mean of 28 fragments (range 16-60). A total of four tumors were tested. Tumor fragments were tested with a single dose of each reagent. Angiogenic initiation, angiogenic growth, and overall angiogenic effect were determined for each treatment group using a previously validated scale. RESULTS: All four breast cancer specimens tested developed an angiogenic response, sprouting neovessels in vitro in a time-dependent fashion (r = 0.84, P = 0.0007). Taxol statistically inhibited angiogenesis in all four specimens with decreases in the mean angiogenic initiation, angiogenic growth, and overall effect that were 69%, 81%, and 94% of control values, respectively. Vincristine and 5-FU inhibited the mean overall angiogenic effect by 89% and 82% compared with control, respectively. Adriamycin inhibited overall effect 49%. Methotrexate was less effective. CONCLUSION: Freshly harvested breast cancer specimens develop an angiogenic response in a fibrin-thrombin clot-based angiogenesis model and respond to treatment with antineoplastic/antiangiogenic drugs. The antiangiogenic potential of commonly used breast cancer drugs varied among individual tumors. Data obtained from this model is unique and might potentially be used to further enhance the efficacy of cytotoxic regimens and individualize patient therapy.

Plasma Neurokinin A Levels Predict Survival in Well-Differentiated Neuroendocrine Tumors of the Small Bowel.

OBJECTIVES: Elevated neurokinin A (NKA) levels are associated with poor prognosis in patients with small bowel neuroendocrine tumors. We hypothesized that patients with NKA levels that remain elevated despite treatment with surgical cytoreduction have a poor prognosis. METHODS: Patients diagnosed with small bowel neuroendocrine tumors who underwent surgical cytoreduction at our institution were identified. Demographics, histopathologic characteristics, and biochemical data were collected. Patients were grouped by the trend of their NKA levels (group 1, continuously normal; group 2, transiently elevated but normalized after therapy; group 3, remained elevated despite therapy). Survival rates were calculated from the date of the patient's first NKA level. RESULTS: Serial NKA values after surgical cytoreduction were monitored in 267 patients. Kaplan-Meier 2-year, 5-year, and 10-year survival rates were as follows: group 1 (n = 157), 97%, 89%, and 62%; group 2 (n = 78), 99%, 90%, and 78%; and group 3 (n = 32), 88%, 69%, and 0%. Survival rates were statistically significant between groups 1 and 3 and between groups 2 and 3 (P < 0.01). CONCLUSIONS: Serial monitoring of plasma NKA levels is useful in identifying patients who have a poor prognosis. Elevated NKA levels can indicate the need for immediate therapeutic intervention.

An assay to measure angiogenesis in human fat tissue.

BACKGROUND: Inhibition of angiogenesis reverses rodent obesity. A validated assay in human fat tissue is needed to study the role of angiogenesis in human obesity. METHODS: Human fat tissue fragments from surgery were placed in 96-well plates, embedded in fibrin thrombin clot and overlaid with cell culture media containing 20% fetal bovine serum. After 15 days, the clots were examined by histology and electron microscopy. The effect of taxol, cobalt chloride and a heparin-steroid combination was tested in the fat tissue assay and compared to the validated human placental vein angiogenesis model (HPVAM). RESULTS: Blood vessels initiated growth and elongated from the fat tissue fragments over 15 days. Presence of blood vessels was confirmed with histology and electron microscopy. Taxol at 10(-6) and 10(-7) M completely inhibited angiogenesis, while Taxol 10(-8) and 10(-9) M and the heparin-steroid partially inhibited angiogenesis. The response to taxol and heparin-steroid was similar to that of the HPVAM, a validated angiogenesis assay. Cobalt chloride, a stimulator of vascular endothelial growth factor (VEGF) stimulated angiogenesis initiation at 10(-9) M in fat tissue and the HPVAM, but at 10(-10) M blood vessel growth was stimulated only in the fat assay. CONCLUSION: This angiogenesis assay based on human fat tissue uses three-dimensionally intact human tissue. The vessels are derived from quiescient vessels within the fat. These properties allow the angiogenic switch to be evaluated in an in vitro setting. The angiogenic response of fat tissue is not identical to placental tissue. This assay allows exploration of angiogenesis in fat tissue.

The safety and efficacy of a dietary herbal supplement and gallic acid for weight loss.

The objective of this study was to test the safety and efficacy of NT, a dietary herbal supplement made from rhubarb, ginger, astragulus, red sage, and turmeric, combined with gallic acid (GA) to reduce food intake and cause weight loss. A total of 105 healthy subjects, 18-60 years old with a body mass index of 25-35 kg/m(2) and on no chronic medication, were randomized to a 300 mg/1.2 g NT-GA combination, a 600 mg/2.4 g NT-GA combination, or placebo in three divided doses daily for 24 weeks. Food intake was measured at baseline and 2 weeks, and safety parameters were followed regularly. Pharmacokinetic studies of a 200 mg/800 g NT-GA combination and 800 mg GA alone were performed with and without food. There was no dose-related weight loss or reduction in food intake at the 8-week analysis, and the study was terminated early. Pharmacokinetic studies showed plasma levels of GA did not increase above 10 microM and were not dose-related. The NT-GA at all concentrations was well tolerated, but was ineffective in causing weight loss or in suppressing food intake. Pharmacokinetics suggested that GA plasma levels were limited by oral absorption, and may be the reason for lack of efficacy.

Aggressive Surgical Approach to the Management of Neuroendocrine Tumors: A Report of 1,000 Surgical Cytoreductions by a Single Institution.

BACKGROUND: Neuroendocrine tumors (NETs) are rare neoplasms. Our group has treated more than 2,000 NET patients and has performed more than 1,000 surgical cytoreductive procedures. STUDY DESIGN: Records of 834 NET patients who underwent surgical cytoreduction at our institution were reviewed. Demographic information, intraoperative findings, extent of disease, complications, and survival rates were calculated. RESULTS: Eight hundred patients underwent 1,001 cytoreductive operations. Sixty-five percent had small bowel primaries. One hundred and thirty-eight patients presented with an unknown primary site, which was localized intraoperatively in 89% of these cases. The intraoperative complication rate was 9%. The incidence of intraoperative carcinoid crisis was 1%. Mean ± SD operative time was 368 ± 146 minutes. Mean ± SD hospital stay was 9 ± 10 days. Minor postoperative complications occurred after 43% of procedures and major postoperative complications were noted after 19% of procedures. The 30-day postoperative mortality rate was 2%. Median overall survival (OS) for patients with pancreatic NETs was 124 months. The 5-, 10-, and 20-year OS rates for patients with pancreatic NETs were 67%, 51%, and 36%, respectively. The life expectancy difference (between OS and actuarial survival) after surgical cytoreduction for patients with pancreatic NETs was 16.6 years. Median OS for patients with small bowel NETs was 161 months. The 5-, 10-, and 20-year OS rates for patients with small bowel NETs were 84%, 67% and 31%, respectively. The life expectancy difference after surgical cytoreduction for patients with small bowel NETs was 11.7 years. CONCLUSIONS: Surgical cytoreduction in NET patients has low morbidity and mortality rates and results in prolonged survival. We believe that surgical cytoreduction should play a major role in the care of patients with NETs.

Prognostic Factors in Typical and Atypical Pulmonary Carcinoids.

BACKGROUND: Typical and atypical carcinoids represent approximately 2% of all lung tumors. Survival of patients with typical bronchial carcinoids, unlike the survival of patients with most lung tumors, is generally long but dependent on stage. We report the findings of the Ochsner Medical Center/Louisiana State University (LSU) Health Sciences Center neuroendocrine tumor (NET) program. METHODS: A database with all patients seen at the Ochsner Medical Center/LSU NET program was queried for patients with bronchopulmonary NET. We included patients who had confirmed pathologic bronchopulmonary carcinoid and who had at least 1 clinic visit. Patients with large or small cell NETs or diffuse idiopathic pulmonary neuroendocrine cell hyperplasia were excluded. RESULTS: A total of 169 patients seen from January 1996 to March 2015 met the inclusion criteria. The mean age at diagnosis was 53 years. Of the tumors, 51% percent (86/169) were well-differentiated, 12% (21/169) were moderately differentiated, and 85% and 53% were positive on positron emission tomography and octreotide scanning, respectively. The 5- and 10-year survival rates were 88% and 81% for well-differentiated tumors and 80% and 42% for moderately differentiated tumors, respectively. The 10-year survival rates stratified by Ki-67 index ranges 0-2%, >2%-10%, and >10% were 90%, 72%, and 44%, respectively (P<0.05). CONCLUSION: Overall, patients with bronchial carcinoids have long 5- and 10-year survival rates. We found significant survival differences between nodal status, differentiation status, and carcinoid phenotype. Interestingly, the difference in survival stratified by Ki-67 indices was statistically significant despite its absence in the World Health Organization grading system. As with gastroenteropancreatic NETs, Ki-67 index could become a valuable prognostic indicator for bronchial carcinoids.