Outcomes following percutaneous upper gastrointestinal decompressive tube placement for malignant bowel obstruction in ovarian cancer.

OBJECTIVE: The objective of this study was to evaluate peri-operative and survival outcomes of ovarian cancer patients undergoing percutaneous upper gastrointestinal decompression for malignant bowel obstruction (MBO). METHODS: Retrospective chart review was used to identify patients with ovarian, peritoneal, or fallopian tube cancer who underwent palliative decompressive treatment for MBO from 1/2002 to 12/2010. Kaplan-Meier methods were used to estimate the median survival (MS) and multivariate analysis used to determine if any variables were associated with the hazard of death. RESULTS: Fifty-three patients met inclusion criteria. Median length of diagnosis prior to intervention was 21 months. Fifteen (28.3%) patients experienced complications and 9 required revision. Forty-nine (92.5%) experienced relief of symptoms after placement, and 91% tolerated some form of oral intake. Following placement, 19 (36%) patients received additional chemotherapy and 21(41%) patients received total parental nutrition (TPN). Thirty-five patients were discharged home/outpatient facility, 16 to hospice care, and 2 died prior to discharge. MS for all patients was 46 days. Patients who received chemotherapy had a MS of 169 days compared to 33 days (p<0.001). We failed to find an association between survival and TPN or performance status. CONCLUSIONS: Malignant bowel obstruction is a common complication of ovarian cancer. Management is palliative; risks and benefits of any therapy must be considered. Percutaneous decompressive therapy provides relief from associated symptoms, and allows patients to be discharged home. Median survival in this group is limited, and decisions regarding aggressive therapy should be individualized.

Perioperative Mortality Does Not Explain Racial Disparities in Gastrointestinal Cancer.

BACKGROUND: Racial minorities with gastrointestinal cancer suffer disproportionately poor overall and disease-specific survival. We used a nationally representative sample to examine the relationship between race/ethnicity and mortality and determine whether these disparities were observed in the perioperative period. MATERIALS AND METHODS: The Nationwide Inpatient Sample (NIS) was used to examine patients undergoing surgery for cancers of the esophagus, stomach, pancreas, colon and rectum ("GI cancer") between 2008 and 2012. Logistic regression was used to evaluate whether race/ethnicity was associated with perioperative mortality after adjusting for sociodemographic characteristics, perioperative factors and presentation (ER vs elective). RESULTS: A total of 110,044 subjects were identified, including 75.8% Whites, 10.5% Black patients, 7.2% Hispanic patients, and 3.1% Asian/Pacific Islanders (API). Whites were generally older than minorities. In adjusted multivariable generalized linear mixed logistic models, no increase in perioperative mortality was seen for minorities. Worse outcomes were observed for those with higher Elixhauser comorbidity score (OR 6.90, CI 5.96-7.99), lower income region (OR 1.24, CI 1.10-1.40), males (OR 1.54, CI 1.42-1.68), and those without private insurance (Medicare OR 1.34, CI 1.16-1.55; Medicaid OR 1.27, CI 1.02-1.58; self-pay OR 1.64, CI 1.24-2.17). Differences in mortality were predominantly driven by comorbidities (pseudo %ΔR2 = 38.56%) and only minimally by race (pseudo %ΔR2 = 0.49%). CONCLUSION: Minority groups do not suffer higher rates of perioperative mortality for GI cancer surgeries after controlling for clinical and demographic factors. Future work to address cancer disparities should focus on areas in the cancer care trajectory such as cancer screening, surveillance, socioeconomic factors, and access.

A computerized analysis of robotic versus laparoscopic task performance.

INTRODUCTION: Robotic technology has been postulated to improve performance in advanced surgical skills. We utilized a novel computerized assessment system to objectively describe the technical enhancement in task performance comparing robotic and laparoscopic instrumentation. METHODS AND PROCEDURES: Advanced laparoscopic surgeons (2-10 yrs experience) performed three unique task modules using laparoscopic and Telerobotic surgical instrumentation (Intuitive Surgical, Sunnyvale, CA). Performance was evaluated using a computerized assessment system (ProMIS, Dublin, Ireland) and results were recorded as time (s), path (mm) and precision. Each surgeon had an initial training session followed by two testing sessions for each module. A paired Student's t-test was used to analyze the data. RESULTS: Ten surgeons completed the study. 8/10 surgeons had significant technical enhancement utilizing robotic technology. CONCLUSIONS: The ProMIS computerized assessment system can be modified to objectively obtain task performance data with robotic instrumentation. All the tasks were performed faster and with more precision using the robotic technology than standard laparoscopy.

Oxythiamine and dehydroepiandrosterone inhibit the nonoxidative synthesis of ribose and tumor cell proliferation.

This study investigates the significance of the glucose-6-phosphate dehydrogenase (G6PD) catalyzed oxidative and the transketolase (TK) catalyzed nonoxidative pentose cycle (PC) reactions in the tumor proliferation process by characterizing tumor growth patterns and synthesis of the RNA ribose moiety in the presence of respective inhibitors of G6PD and TK. Mass spectra analysis of 13C-labeled carbons revealed that these PC reactions contribute to over 85% of de novo ribose synthesis in RNA from [1,2-(13)C]glucose in cultured Mia pancreatic adenocarcinoma cells, with the fraction synthesized through the TK pathway predominating (85%). Five days of treatment with the TK inhibitor oxythiamine (OT) and the G6PD inhibitor dehydroepiandrosterone-sulfate (0.5 microM each) exerted a 39 and a 23% maximum inhibitory effect on cell proliferation in culture, which was increased to 60% when the two drugs were administered in combination. In vivo testing of 400 mg/kg OT or dehydroepiandrosterone-sulfate in C57BL/6 mice hosting Ehrlich's ascitic tumor cells revealed a 90.4 and a 46% decrease in the final tumor mass after 3 days of treatment. RNA ribose fractional synthesis through the TK reaction using metabolites directly from glycolysis declined by 9.1 and 23.9% after OT or the combined treatment, respectively. Nonoxidative PC reactions play a central regulating role in the carbon-recruiting process toward de novo nucleic acid ribose synthesis and cell proliferation in vitro and in vivo. Therefore, enzymes or substrates regulating the nonoxidative synthesis of ribose could also be the sites to preferentially target tumor cell proliferation by new anticancer drugs.

Genetic alterations in gastrinomas and nonfunctioning pancreatic neuroendocrine tumors: an analysis of p16/MTS1 tumor suppressor gene inactivation.

Neoplasms of the endocrine pancreas are extremely rare, and molecular mechanisms influencing their development are poorly understood. Nevertheless, gastrinomas have become a paradigm for the study of hormonally active tumors. In the present study, 12 gastrinoma and nonfunctioning pancreatic neuroendocrine tumor specimens were evaluated for genetic alterations of the p16/MTS1 tumor suppressor gene. DNA extracted from microdissected portions of paraffin-embedded tumor sections were examined for mutations and homozygous deletions using "Cold" single-strand conformation polymorphism and semiquantitative PCR-based analyses, respectively. Samples were also analyzed for the presence of 5' CpG island hypermethylation using methylation-specific PCR. The p16/MTS1 gene was found to be homozygously deleted in 41.7% of tumors and methylated in 58.3%, but no mutations were identified by single-strand conformation polymorphism analyses. Overall, 91.7% of the specimens demonstrated inactivating alterations in p16/MTS1. These data suggest that transcriptional silencing of p16/MTS1 is a frequent event in these rare and poorly understood tumors.

Identification and sequencing of the Syrian Golden hamster (Mesocricetus auratus) p16(INK4a) and p15(INK4b) cDNAs and their homozygous gene deletion in cheek pouch and pancreatic tumor cells.

Previous studies have shown that the p16(INK4a) tumor suppressor gene is inactivated in up to 98% of human pancreatic cancer specimens and 83% of oral squamous cell carcinomas. Inactivation of the related p15(INK4b) gene has also been identified in a number of tumors and cell lines, however, its role as an independent tumor suppressor remains to be elucidated. Chemically-induced tumors in the Syrian Golden hamster (Mesocricetus auratus) have been shown to be excellent representative models for the comparative development and progression of a number of human malignancies. The purpose of this study was to determine the importance of the p16(INK4a) and p15(INK4b) genes in two experimental hamster models for human pancreatic and oral carcinogenesis. First, hamster p16(INK4a) and p15(INK4b) cDNAs were cloned and sequenced. The hamster p16(INK4a) cDNA open reading frame (ORF) shares 78%, 80%, and 81% identity with the human, mouse, and rat p16(INK4a) sequences, respectively. Similarly, the hamster p15(INK4b) cDNA ORF shares 82% and 89% sequence identity with human and mouse p15(INK4b), respectively. Second, a deletion analysis of hamster p16(INK4a) and p15(INK4b) genes was performed for several tumorigenic and non-tumorigenic hamster cell lines and revealed that both p16(INK4a) and p15(INK4b) were homozygously deleted in a cheek pouch carcinoma cell line (HCPC) and two pancreatic adenocarcinoma cell lines (KL5B, H2T), but not in tissue matched, non-tumorigenic cheek pouch (POT2) or pancreatic (KL5N) cell lines. These data strongly suggest that homozygous deletion of the p16(INK4a) and p15(INK4b) genes plays a prominent role in hamster pancreatic and oral tumorigenesis, as has been well established in correlative studies in comparable human tumors. Furthermore, this study supports the comparative importance of the hamster pancreatic and cheek pouch models of carcinogenesis in subsequent mechanistic-, therapeutic-, and preventive-based studies aimed at providing important translational data applicable to pancreatic adenocarcinoma and oral squamous cell carcinoma in humans.

Variable effect of streptozotocin-diabetes on the growth of hamster pancreatic cancer (H2T) in the Syrian hamster and nude mouse.

BACKGROUND: Streptozotocin-diabetes prevents induction of pancreatic tumors in several animal models and inhibits the growth of established human pancreatic cancer implants in nude mice. However, it also promotes growth of the hamster pancreatic cancer cell line, H2T, in the Syrian hamster. To test the hypothesis that these contradictory effects are due to tumor host differences, the growth of the H2T cell line was examined in the streptozotocin-diabetic nude mouse. METHODS: H2T cells were implanted subcutaneously into streptozotocin-diabetic nude mice (n = 10) and untreated control mice (n = 10). After 21 days, tumors were excised and weighed. Plasma insulin and somatostatin were determined by radioimmunoassay. RESULTS: After 3 weeks, tumors in the control group weighed 118 mg and tumors in the diabetic group weighed 28 mg (p < 0.001). Plasma insulin was significantly decreased in the streptozotocin-treated animals compared with control animals (insulin, 23 microU/ml vs 31 microU/ml; p < 0.001). In contrast, somatostatin was significantly elevated in the streptozotocin-diabetic group compared with the control group (somatostatin, 179 pg/ml versus 54 pg/ml, p < 0.001). Competitive binding studies revealed specific cell surface receptors for insulin (Kd, 15.5 nmol/L), and somatostatin (Kd, 2.5 nmol/L) on the H2T cells. In an in vitro cell proliferation assay, cell division was promoted by insulin (p < 0.01, maximum +11%) and inhibited by somatostatin (p < 0.01, maximum -18%). CONCLUSIONS: The variable effect of streptozotocin-diabetes on pancreatic cancer growth is due to differences in the tumor host. The growth of pancreatic cancer, particularly in streptozotocin-diabetic nude mice, may be influenced by gut peptides in a receptor-dependent fashion.

Expression of the somatostatin receptor subtype-2 gene predicts response of human pancreatic cancer to octreotide.

BACKGROUND: Somatostatin inhibits proliferation of many solid tumors. The current study examines whether inhibition of the growth of pancreatic cancer by the somatostatin analog, octreotide, requires tumor expression of somatostatin receptors. METHODS: We studied five human pancreatic cancer cell lines, Capan-1, Capan-2, CAV, MIA PaCa-2, and Panc-1. Solid tumors were established in nude mice (n = 20/cell line) by flank injection of tumor cells. Subcutaneous octreotide (500 micrograms/kg/day) was administered by osmotic pumps to 10 of the animals in each group, and the other 10 received control infusions of saline solution. On day 36, the tumors were excised and weighed. Plasma levels of the putative trophic peptides cholecystokinin, epidermal growth factor (EGF), insulin-like growth factor-1 (IGF-1), and insulin were assessed by radioimmunoassay. Each of the five cell lines was assayed for the presence of cell surface somatostatin receptors by using whole cell competitive binding assays with 125I-somatostatin. Expression of the somatostatin receptor subtype-2 (SSR2) gene was determined with reverse transcriptase-polymerase chain reactions. Southern blot hybridization was used to assess the presence of the SSR2 gene. RESULTS: Octreotide inhibited tumor growth in the MIA PaCa-2 group (512 +/- 75 mg control versus 285 +/- 71 mg treated; p < 0.05) but had no significant effect on tumor weight in the other four cell lines. Plasma levels of cholecystokinin, epidermal growth factor, insulin-like growth factor-1, and insulin were not altered by chronic octreotide infusion. Cell surface somatostatin receptors and SSR2 gene expression were detected only in the MIA PaCa-2 tumors. The gene for the SSR2 receptor was found in all five tumor lines. CONCLUSIONS: Octreotide-mediated inhibition of pancreatic cancer growth is dependent on expression of somatostatin receptors. The expression of somatostatin receptors should be considered in the design and interpretation of clinical trials with somatostatin analogs for treatment of pancreatic cancer.

Dehydroepiandrosterone-sulfate inhibits pancreatic carcinoma cell proliferation in vitro and in vivo.

BACKGROUND: Dehydroepiandrosterone-sulfate (DHEA-S) is a potent inhibitor of glucose-6 phosphate dehydrogenase, the rate limiting enzyme of the hexose monophosphate shunt, a biochemical pathway that provides substrate for DNA synthesis in neoplastic tissue. DHEA-S has been shown to inhibit the growth of neoplasms arriving from human skin, lung, colon, and mammary tissue. This study evaluates the effect of DHEA-S on human pancreatic cancer cell lines in vitro and in vivo. METHODS: In vitro, the human pancreatic adenocarcinoma cell lines MiaPaCa-2, Capan-1, Capan-2, CAV and Panc-1 were treated with concentrations of 1.9 mumol/L to 1000 mumol/L DHEA-S in 1% dimethylsulfoxide (DMSO) for 5 consecutive days. Cell proliferation was determined by a nonradioactive cell proliferation assay and compared with DMSO treated controls. In vivo testing was performed by inoculating two cell lines, MiaPaCa-2 and Panc-I, into the flank of 40 male nude athymic mice in four study groups. After 1 week of growth, 667 mg/kg DHEA-S in 1% DMSO or 0.2 ml 1% DMSO alone in the control group was administered by daily intraperitoneal injection. Body weight and tumor size was recorded weekly, and tumor weight was measured after 3 weeks of treatment. RESULTS: In vitro cell proliferation was decreased in the five cell lines by 36% to 62% of controls (p < 0.001) at 500 mumol/L DHEA-S. In vivo, after 2 weeks, tumor size was only 76% (p < 0.008) and 67% (p < 0.005) of the controls. After 3 weeks of treatment, tumor size was 73% (p < 0.001) and 53% (p < 0.001) of controls, and tumor weight was decreased by 73% in MiaPaCa-2 (p < 0.001) and 66% in Panc-1 (p < 0.001). Radioimmunoassay measurements of DHEA-S and testosterone from DHEA-S treated mouse plasma showed a significant increase in circulating levels of these hormones. CONCLUSIONS: DHEA-S achieves high serum levels after intraperitoneal injection without elevation of serum testosterone levels and produces no significant toxicity. Treatment with DHEA-S results in a significant reduction of proliferation of human pancreatic cancer cells in culture and when grown as subcutaneous tumors in athymic nude mice.

Reducing overtriage without compromising outcomes in trauma patients.

HYPOTHESIS: Changing category 1 criteria to include primarily physiologic and anatomic indicators of injury, eliminating mechanism of injury criteria, decreases the rate of overtriage without compromising outcomes. METHODS: Retrospective review of our American College of Surgeons-verified level I trauma registry from January 1, 1996, to December 31, 1998, comparing patients before and after trauma alert criteria changes. RESULTS: There was a significant decrease in category 1 alerts, representing a reduction in overtriage. There was a concomitant increase in injury severity and mortality in category 1 patients. There was no significant change in injury severity or mortality for category 2 patients. CONCLUSIONS: There was a significant reduction in overtriage of trauma patients demonstrated without an appreciable impact on patient outcome. Changing trauma response criteria to more physiologic and anatomic indicators allowed improved triage of trauma patients, which improves resource allocation.

Outcome analysis of long-term survivors following pancreaticoduodenectomy.

The long-term sequelae of pancreaticoduodenectomy are not completely understood. In the present study nutritional status, pancreatic function, and subjective quality-of-life parameters were evaluated in 45 patients who had previously undergone either pylorus-preserving pancreaticoduodenectomy (PPPD) or standard pancreaticoduodenectomy (SPD). Quality-of-life parameters, as measured by the Short Form-36 health survey, demonstrated no significant differences between the subgroups and normal control subjects in six of the eight domains for physical and mental health. Patients who had undergone SPD were noted to have significantly lower scores for general health and vitality than either age-matched control subjects or those who had undergone PPPD. No differences in nutritional parameters or indicators of pancreatic exocrine function between the two groups were identified. An elevated hemoglobin A1c value was seen in only one patient who was not diabetic preoperatively. Our data indicate that long-term survivors of pancreaticoduodenectomy generally feel as good as their normal counterparts, although SPD may result in some health satisfaction deficits. Nutritional status and pancreatic exocrine function are not improved in patients undergoing a pylorus-preserving procedure, and postoperative pancreatic endocrine dysfunction is unusual in both groups.

Endoscopic management of stomal stenosis after Roux-en-Y gastric bypass.

BACKGROUND: In the United States, Roux-en-Y gastric bypass has evolved into the procedure of choice for clinically severe obesity. Stomal stenosis resulting in gastric outlet obstruction is a recognized complication. Endoscopic balloon dilation is often used to treat this condition. To evaluate the safety and efficacy of endoscopic management of stomal stenosis we evaluated our treatment methods and outcomes. METHODS: The records of all patients undergoing Roux-en-Y gastric bypass from 1 July 2000 to 30 June 2002 were studied. Stenosis was defined as signs and symptoms of obstruction with inability to cannulate the gastrojejunostomy using an 8.5-mm diagnostic endoscope. Charts were reviewed and demographic data, operative course, symptoms, and outcomes were recorded. RESULTS: A total of 562 patients underwent Roux-en-Y gastric bypass for obesity during the study period. Of these, 38 patients underwent endoscopic balloon dilation for stomal stenosis, for a stenosis rate of 6.8%. The average time from surgery to initial dilation was 7.7 weeks (range 3 to 24). The average number of dilations required was 2.1 (range one to six). The mean initial balloon size was 13 mm and the mean final balloon size was 16 mm. Two patients failed endoscopic dilation and proceeded to surgery, including one patient who developed pneumomediastinum and pneumothorax after dilation. All patients were relieved of their gastric outlet obstruction. The success rate for endoscopic balloon dilation was 95% with a 3% complication rate. CONCLUSIONS: In our experience, the rate of gastrojejunostomy stenosis following Roux-en-Y gastric bypass is 6.8%. Endoscopic balloon dilation is a safe and effective therapy for stomal stenosis with a high success rate. It should be considered an appropriate intervention with a low risk for reoperation.

Nonoxidative pentose phosphate pathways and their direct role in ribose synthesis in tumors: is cancer a disease of cellular glucose metabolism?

Pentose phosphate pathways (PPP) are considered important in tumor proliferation processes because of their role in supplying tumor cells with reduced NADP and carbons for intracellular anabolic processes. Direct involvement of PPP in tumor DNA/RNA synthesis is not considered as significant as in lipid and protein syntheses. Currently, PPP activity in tumor cells is measured by lactate production, which shows a moderate activity: about 4% to 7% compared with glycolysis. Recent data generated in our laboratory indicate that PPP are directly involved in ribose synthesis in pancreatic adenocarcinoma cells, through oxidative steps (< 31%) and transketolase reactions (69%). These findings raise serious questions about the adequacy of lactate in measuring PPP activity in tumors. We hypothesize that ribose, not lactate, is the major product of PPP in tumor cells. Control of both oxidative and nonoxidative PPP may be critical in the treatment of cancer. PPP are substantially involved in the proliferation of human tumors, which raises the prospect of new treatment strategies targeting specific biochemical reactions of PPP by hormones related to glucose metabolism, controlling thiamine intake, the cofactor of the nonoxidative transketolase PPP reaction, or treating cancer patients with antithiamine analogues.

Gastrointestinal hormones as potential adjuvant treatment of exocrine pancreatic adenocarcinoma.

CONCLUSION: Gastrointestinal hormones and their antagonists can alter the growth of pancreatic adenocarcinoma in vitro and in vivo. The potential clinical benefit of this approach deserves further study. BACKGROUND: Epithelial cell growth is normally under hormonal control. Hormones also affect the growth of many epithelial cancers, and this fact is used to modify tumor growth. Pancreatic epithelial cell growth is under the influence of gastrointestinal hormones. This article reviews experiments designed to determine the effect of gastrointestinal hormones on the growth of pancreatic adenocarcinoma. METHODS: Eighty-eight articles were identified from a Medline search using the terms pancreatic adenocarcinoma and the individual names of gastrointestinal hormones. The experimental design and results of these studies are reviewed. RESULTS: In general, somatostatin, vasoactive intestinal polypeptide, pancreatic polypeptide, and pancreastatin inhibit pancreatic adenocarcinoma growth. Cholecystokinin, secretin, bombesin, gastrin, EGF, TGF-alpha, insulin, and IGF-1 have a growth-promoting effect.

Oral dehydroepiandrosterone inhibits the growth of human pancreatic cancer in nude mice.

BACKGROUND: Dehydroepiandrosterone (DHEA), an androgen precursor, inhibits the induction of pancreatic cancer in some animal models. Our laboratory has previously demonstrated that the sulfated form of DHEA (DHAS), when administered by intraperitoneal injection, inhibits the growth of pancreatic cancer xenografts in nude mice. In the present study, we hypothesize that DHEA-mediated pancreatic cancer growth inhibition is associated with alterations in plasma sex hormone concentrations. MATERIALS AND METHODS: Forty male, nude, athymic mice were fed either Teklad 22/5 rodent diet or diet supplemented with 0.6% DHEA ad libitum. Four weeks following the institution of the experimental diets, 1 x 10(6) MiaPaCa-2 cells were injected into the right flank of each animal. Tumor area was recorded weekly and tumor weights were measured after 5 weeks. Plasma DHAS, testosterone, and progesterone concentrations were determined by radioimmunoassay. RESULTS: Plasma DHAS, testosterone, and progesterone concentrations were all significantly elevated in the DHEA-treated group. DHEA-treated mouse plasma DHAS concentrations were approximately 50-fold higher than controls. Mean tumor weight was significantly reduced in the DHEA group (68.9 +/- 39.1 vs 121.0 +/- 64.3). DHEA treatment did not result in significant animal weight reductions and toxic side effects were not observed. CONCLUSIONS: Dietary supplementation with 0.6% DHEA causes significant elevations in plasma DHAS concentration. DHEA administration significantly inhibits pancreatic cancer cell growth at plasma concentrations 1 x 10(5)-fold lower than previously reported. The mechanism of action may involve elevated concentrations of sex hormones.

Identification of MEN1 mutations in sporadic enteropancreatic neuroendocrine tumors by analysis of paraffin-embedded tissue.

Gastrinomas and other gastrointestinal neuroendocrine tumors may occur sporadically or as part of the inherited syndrome multiple endocrine neoplasia type 1 (MEN1). Mutations in the recently identified MEN1 gene have been described in sporadic gastrinomas and insulinomas. This study describes techniques used to identify mutations in the MEN1 gene in DNA extracted from paraffin-preserved tissue. Two novel mutations are identified in the MEN1 gene from nine archived paraffin-embedded neuroendocrine tumors, demonstrating that retrospective genetic analysis can be used to identify mutations in the MEN1 gene from preserved tissue. Conditions are provided by which paraffin-embedded tissue can be used as a source of genetic material for sequence information of sufficient quality for mutational studies of the MEN1 gene. It should also be possible to apply this retrospective genetic analysis of paraffin-embedded tissue to other disease models.