Comparison of the duration of hospital stay after laparoscopic or open distal pancreatectomy: randomized controlled trial.

BACKGROUND: Studies have suggested that laparoscopic distal pancreatectomy (LDP) is advantageous compared with open distal pancreatectomy (ODP) regarding hospital stay, blood loss and recovery. Only one randomized study is available, which showed enhanced functional recovery after LDP compared with ODP. METHODS: Consecutive patients evaluated at a multidisciplinary tumour board and planned for standard distal pancreatectomy were randomized prospectively to LDP or ODP in an unblinded, parallel-group, single-centre superiority trial. The primary outcome was postoperative hospital stay. RESULTS: Of 105 screened patients, 60 were randomized and 58 (24 women, 41 per cent) were included in the intention-to-treat analysis; there were 29 patients of mean age 68 years in the LDP group and 29 of mean age 63 years in the ODP group. The main indication was cystic pancreatic lesions, followed by neuroendocrine tumours. The median postoperative hospital stay was 5 (i.q.r. 4-5) days in the laparoscopic group versus 6 (5-7) days in the open group (P = 0·002). Functional recovery was attained after a median of 4 (i.q.r. 2-6) versus 6 (4-7) days respectively (P = 0·007), and duration of surgery was 120 min in both groups (P = 0·482). Blood loss was less with laparoscopic surgery: median 50 (i.q.r. 25-150) ml versus 100 (100-300) ml in the open group (P = 0·018). No difference was found in the complication rates (Clavien-Dindo grade III or above: 4 versus 8 patients respectively). The rate of delayed gastric emptying and clinically relevant postoperative pancreatic fistula did not differ between the groups. CONCLUSION: LDP is associated with shorter hospital stay than ODP, with shorter time to functional recovery and less bleeding. Registration number: ISRCTN26912858 ( www.isrctn.com).

ANTECEDENTES: Los estudios han sugerido que la pancreatectomía distal laparoscópica (laparoscopic dital pancreatectomy, LDP) resulta ventajosa en comparación con la pancreatectomía distal por vía abierta (open distal pancreatectomy, ODP) respecto a la estancia hospitalaria, pérdida sanguínea y recuperación. Solamente existe un estudio aleatorizado que muestra una mejor recuperación funcional después de la LDP en comparación con la ODP. MÉTODOS: En un ensayo de superioridad unicéntrico, abierto y de grupos paralelos, los pacientes consecutivos evaluados por el comité multidisciplinario de tumores y a los que se indicó una pancreatectomía distal estándar fueron asignados al azar de forma prospectiva a LDP o ODP. El resultado primario fue la estancia hospitalaria postoperatoria. RESULTADOS: De 105 pacientes evaluados, 60 fueron aleatorizados, de los cuales 58 pacientes (24 mujeres; 41%) fueron incluidos y asignados a LDP (n = 29; edad media 68 años) o ODP (n = 29; edad media 63 años) e incluidos en un análisis por intención de tratamiento. La principal indicación fueron las lesiones quísticas del páncreas seguida de los tumores neuroendocrinos. La estancia hospitalaria postoperatoria fue de 5 días (rango intercuartílico, interquartile range, IQR 4-5) en el grupo laparoscópico versus 6 (5-7) días en el grupo de cirugía abierta (P = 0,002). La recuperación funcional se alcanzó después de 4 (2-6) versus 6 (4-7) días (P = 0,007), y el tiempo operatorio fue de 120 minutos en ambos grupos (P = 0.48). Las pérdidas hemáticas fueron menores en la cirugía laparoscópica, 50 (25-150) versus 100 mL (100-300) (P = 0,018). No se hallaron diferencias en las tasas de complicaciones (grado Clavien-Dindo ≥ 3) con 4 versus 8 pacientes en el grupo laparoscópico y en el grupo abierto, respectivamente. La tasa de retraso en el vaciamiento gástrico y de fístula postoperatoria clínicamente relevante no difirió entre los grupos. CONCLUSIÓN: La pancreatectomía distal laparoscópica se asocia con una estancia hospitalaria más corta en comparación con la cirugía abierta, con un menor tiempo para la recuperación funcional y menos hemorragia.

Common variables in European pancreatic cancer registries: The introduction of the EURECCA pancreatic cancer project.

BACKGROUND: Quality assurance of cancer care is of utmost importance to detect and avoid under and over treatment. Most cancer data are collected by different procedures in different countries, and are poorly comparable at an international level. EURECCA, acronym for European Registration of Cancer Care, is a platform aiming to harmonize cancer data collection and improve cancer care by feedback. After the prior launch of the projects on colorectal, breast and upper GI cancer, EURECCA's newest project is collecting data on pancreatic cancer in several European countries. METHODS: National cancer registries, as well as specific pancreatic cancer audits/registries, were invited to participate in EURECCA Pancreas. Participating countries were requested to share an overview of their collected data items. Of the received datasets, a shared items list was made which creates insight in similarities between different national registries and will enable data comparison on a larger scale. Additionally, first data was requested from the participating countries. RESULTS: Over 24 countries have been approached and 11 confirmed participation: Austria, Belgium, Bulgaria, Denmark, Germany, The Netherlands, Slovenia, Spain, Sweden, Ukraine and United Kingdom. The number of collected data items varied between 16 and 285. This led to a shared items list of 25 variables divided into five categories: patient characteristics, preoperative diagnostics, treatment, staging and survival. Eight countries shared their first data. CONCLUSIONS: A list of 25 shared items on pancreatic cancer coming from eleven participating registries was created, providing a basis for future prospective data collection in pancreatic cancer treatment internationally.

Does the Introduction of Laparoscopic Distal Pancreatectomy Jeopardize Patient Safety and Well-Being?

BACKGROUND/PURPOSE: Despite retrospective data indicating short-term superiority for laparoscopic distal pancreatectomy compared to open distal pancreatectomy, the implementation of the procedure has been slow. The aim of this study was to investigate whether patients operated with laparoscopic distal pancreatectomy during the early phase of introduction are at higher risk for complications than patients operated with open distal pancreatectomy. METHODS: A retrospective single-center analysis of patients operated with laparoscopic distal pancreatectomy (n = 37) from the introduction of the procedure and comparison regarding demographic data, preoperative data, operative factors, and postoperative outcomes to patients operated with open distal pancreatectomy was done. RESULTS: Operation duration shortened (195 vs 143 min, p = 0.04) and severe complications reduced (37% vs 6%, p = 0.02) significantly in the laparoscopic distal pancreatectomy group between the first half of the study and the second half. Blood loss was significantly (p < 0.001) lower in the laparoscopic distal pancreatectomy group (75 mL) than in the open distal pancreatectomy group (550 mL), while complication rate and hospital stay as well as the percentage of radical resections were the same. CONCLUSION: Laparoscopic distal pancreatectomy can be introduced without jeopardizing patient safety and well-being during the early learning curve. The procedures should be compared in a prospective randomized manner.

Multivisceral Resection in Patients with Advanced Abdominal Tumors.

BACKGROUND/AIM: Multivisceral resection for advanced tumors can result in prolonged survival but may also increase the risk of postoperative morbidity and mortality. The primary aim of this study was to investigate whether extensive resections increase the severity of postoperative complications. MATERIALS AND METHODS: A retrospective study was conducted between 2009 and 2014 at the Linköping University Hospital surgical department. All patients with a confirmed or presumed malignant disease who underwent a non-standardized surgical procedure requiring a multivisceral resection were included. The primary endpoint was 90-day complications according to the Clavien-Dindo score. RESULTS: Forty-eight patients were included, with an age range of 17-77 years. A median of three organs was resected. The most common diagnoses were neuroendocrine tumor (n = 8), gastric cancer (n = 7), and gastrointestinal stromal tumor (n = 6). One patient died during surgery. Complications ⩾ grade 3b according to Clavien-Dindo score occurred in 10 patients. R0 resection was achieved in 32 patients. No correlation was observed between the number of anastomoses, perioperative blood loss, operative time, and complications. Only postoperative blood transfusion was correlated with severe complications (p = 0.046); however, a tendency toward more complications with an increasing number of resected organs was observed (p = 0.06). CONCLUSION: Multivisceral resection can result in R0, potentially curing patients with advanced tumors. Here, no correlation between extensive resections and complications was observed. Only postoperative blood transfusion was correlated with severe complications.

Associating Liver Partition and Portal Vein Ligation for Primary Hepatobiliary Malignancies and Non-Colorectal Liver Metastases.

BACKGROUND AND AIMS: Associating liver partition and portal vein ligation for staged hepatectomy may increase the possibility of radical resection in the case of liver malignancy. Concerns have been raised about the high morbidity and mortality associated with the procedure, particularly when applied for diagnoses other than colorectal liver metastases. The aim of this study was to analyze the initial experience with associating liver partition and portal vein ligation for staged hepatectomy in cases of non-colorectal liver metastases and primary hepatobiliary malignancies in Scandinavia. MATERIALS AND METHODS: A retrospective analysis of all associating liver partition and portal vein ligation for staged hepatectomy procedures performed at two Swedish university hospitals for non-colorectal liver metastases and primary hepatobiliary malignancies was performed. The primary focus was on the safety of the procedure. RESULTS AND CONCLUSION: Ten patients were included: four had hepatocellular cancer, three had intrahepatic cholangiocarcinoma, one had a Klatskin tumor, one had ocular melanoma metastasis, and one had a metastasis from a Wilms' tumor. All patients completed both operations, and the highest grade of complication (according to the Clavien-Dindo classification) was 3A, which was observed in one patient. No 90-day mortality was observed. Radical resection (R0) was achieved in nine patients, while the resection was R2 in one patient. The low morbidity and mortality observed in this cohort compared with those of earlier reports on associating liver partition and portal vein ligation for staged hepatectomy for diagnoses other than colorectal liver metastases may be related to the selection of patients with limited comorbidity. In addition, procedures other than associating liver partition and portal vein ligation for staged hepatectomy had been avoided in most of the patients. In conclusion, associating liver partition and portal vein ligation for staged hepatectomy can be applied to primary hepatobiliary malignancies and non-colorectal liver metastases with acceptable rates of morbidity and mortality.

Associating liver partition and portal vein ligation for staged hepatectomy in patients with colorectal liver metastases--Intermediate oncological results.

BACKGROUND: Colorectal liver metastases (CRLM) not amenable for resection have grave prognosis. One limiting factor for surgery is a small future liver remnant (FLR). Early data suggests that associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) effectively increases the volume of the FLR allowing for resection in a larger fraction of patients than conventional two-stage hepatectomy (TSH) with portal vein occlusion (PVO). Oncological results of the treatment are lacking. The aim of this study was to assess the intermediate oncological outcomes after ALPPS in patients with CRLM. MATERIAL AND METHODS: Retrospective analysis of all patients with CRLM operated with ALPPS at the participating centres between December 2012 and May 2014. RESULTS: Twenty-three patients (16 male, 7 female), age 67 years (28-80) were operated for 6.5 (1-38) metastases of which the largest was 40 mm (14-130). Six (27.3%) patients had extra-hepatic metastases, 16 (72.7%) synchronous presentation. All patients received chemotherapy, 6 cycles (3-25) preoperatively and 16 (70%) postoperatively. Ten patients (43%) were rescue ALPPS after failed PVO. Severe complications occurred in 13.6% and one (4.5%) patient died within 90 days of surgery. After a median follow-up of 22.5 months from surgery and 33.5 months from diagnosis of liver metastases estimated 2 year overall survival was 59% (from surgery) and 73% (from diagnosis). Liver only recurrences (n = 8), were treated with reresection/ablation (n = 7) while lung recurrences were treated with chemotherapy. CONCLUSION: The overall survival, rate of severe complications and perioperative mortality associated with ALPPS for patients with CRLM is comparable to TSH.

Serum amino acid profile in patients with acute pancreatitis.

Patients in the early phase of acute pancreatitis (AP) have reduced serum levels of arginine and citrulline. This may be of patho-biological importance, since arginine is the substrate for nitric oxide, which in turn is involved in normal pancreatic physiology and in the inflammatory process. Serum amino acid spectrum was measured daily for five days and after recovery six weeks later in 19 patients admitted to the hospital for acute pancreatitis. These patients had abnormal levels of most amino acids including arginine, citrulline, glutamine and glutamate. Phenylalanine and glutamate were increased, while arginine, citrulline, ornithine and glutamine were decreased compared to levels after recovery. NO(2)/NO(3) concentration in the urine, but not serum arginase activity, was significantly increased day 1 compared to day 5 after admission. Acute pancreatitis causes a disturbance of the serum amino acid spectrum, with possible implications for the inflammatory process and organ function both in the pancreas and the gut. Supplementation of selected amino acids could possibly be of value in this severe condition.

Cystic tumors of the pancreas.

The discovery of a cystic lesion in the pancreas implies a challenge for the physician. Approximately 10% are cystic tumors, benign to highly malignant, or true cysts, showing all stages of cellular differentiation, from benign to highly malignant tumors. Malignant cystic tumors are rare and comprise only about 1% of all pancreatic malignancies, they are potentially curable. Therefore, correct diagnosis and treatment of these lesions are of great importance. It is usually not possible to separate a pseudocyst from a benign cyst or a cystic tumor, but there are some signs and findings that could be helpful in the clinical decision. The diagnosis of a cystic pancreatic tumor requires different imaging techniques, including ultrasonography, computerized tomography, magnetic resonance imaging, and magnetic resonance cholangiopancreatography, but to distinguish a pseudocyst or a benign cyst from a potentially malignant lesion can be very difficult. The usefulness of blood tests and investigations of cyst fluid can be questionable. Today, surgical treatment of cystic pancreatic tumors can be performed with low morbidity. Therefore, we conclude that an active strategy with resection of cystic tumors of the pancreas should be recommended.

Cholecystokinin octapeptide induces both proliferation and apoptosis in the rat pancreas.

Cholecystokinin-8 (CCK-8) causes exocrine pancreatic hypertrophy and hyperplasia. High doses of the CCK analogue cerulein causes necrosis and an inflammatory response in the pancreas. We have studied the pancreatic growth response in rats after administration of CCK-8 for 3 days, given either intermittently (20-80 microg/kg) twice a day, or continuously (2.4-48 microg/kg per 24 h). Plasma CCK-8 levels, pancreatic wet weight, water, protein and DNA contents and the pancreatic caspase-3 activity were measured. Cell proliferation was visualized by [3H]thymidine incorporation and apoptosis by TUNEL reaction. Continuous administration of CCK-8 dose-dependently increased the plasma CCK levels, the pancreatic wet weight, protein and DNA contents as well as thymidine labeling index, apoptotic index and caspase-3 activity. Intermittent injections of CCK-8 caused transient raises in plasma CCK, increased apoptotic index and caspase-3 activity, a dose-dependent increase in thymidine labeling but caused a dose-dependent reduction of pancreatic wet weight, protein, and DNA contents. It is concluded that CCK-8 causes both increased proliferation and apoptosis in the pancreas. In case of continuous administration of CCK-8, the proliferation outweighs the apoptosis causing hyperplasia but in the case of intermittent administration the opposite effect is seen.

[Guidelines for management of patients with acute pancreatitis]. / Riktlinjer för handläggning av patienter med akut pankreatit.

During recent years new concepts and methods have been introduced in the management of acute pancreatitis. Severity and risk of complications show wide variation. Outcome is also dependent on the physician's experience and on his local resources. In this light the Swedish Society of Upper Abdominal Surgery has elaborated national guidelines for management. Attention is paid to diagnosis, severity assessment and etiology. Furthermore, guidelines are offered for treatment of mild and severe pancreatitis, as well as for the management of pseudocysts. The role of multidisciplinary intensive care specialist teams in the management of severe disease is emphasized. The guidelines are supported by the Swedish Society of Gastroenterology, the Swedish Society of Gastroenterology, the Swedish Society of Anesthesiology and Intensive Care and by experts from other Nordic countries.

Dissociated insulin and islet amyloid polypeptide secretion from isolated rat pancreatic islets cocultured with human pancreatic adenocarcinoma cells.

Abnormal insulin and islet amyloid polypeptide (IAPP) secretion are usually seen in patients with exocrine pancreatic cancer. The beta-cell dysfunction is a characteristic of the glucose intolerance found in pancreatic cancer patients. The effects of pancreatic cancer cells on insulin and IAPP secretion from beta cells are unclear. In this study, isolated rat pancreatic islets were cocultured with two human pancreatic adenocarcinoma cell lines (Panc-1 and HPAF) and a human colonic adenocarcinoma cell line (HT-29). As a control, islets were incubated in the absence of malignant cells. The accumulation of insulin and IAPP in culture media was measured by radioimmunoassay. Output of insulin and IAPP was decreased in islets cocultured with each malignant cell line. Molar ratio of secreted IAPP and insulin (IAPP/insulin) was increased in the islets cocultured with Panc-1 or HPAF cells, but not HT-29 cells. The decreased insulin and IAPP secretion were partly recovered after Panc-1, HPAF, or HT-29 cells were removed. The IAPP/insulin ratio was normalized after the removal of Panc-1 or HPAF cells. This study indicates that insulin and IAPP secretion are altered by the human adenocarcinoma cells investigated. The impairment induced by pancreatic adenocarcinoma cells is associated with a hypersecretion of IAPP relative to insulin on a molar basis.

Islet amyloid polypeptide tonally inhibits beta-, alpha-, and delta-cell secretion in isolated rat pancreatic islets.

Islet amyloid polypeptide (IAPP, or amylin) is produced in pancreatic beta-cells. The intraislet significance of IAPP is still uncertain. In the present study, paracrine effects of endogenous IAPP and somatostatin were investigated in isolated rat pancreatic islets. The intraislet IAPP activity was inhibited with an IAPP antiserum or a specific antagonist [IAPP-(8-37)]. Somatostatin activity was inhibited by immunoneutralization. Basal insulin and glucagon secretion were not affected by the somatostatin and/or IAPP blockade. Arginine-stimulated insulin and glucagon secretion were dose dependently increased by IAPP antiserum, IAPP-(8-37), and somatostatin antiserum, respectively. Arginine-stimulated somatostatin secretion was dose dependently potentiated by IAPP antiserum. Insulin secretion induced by 16.7 mM glucose was enhanced by IAPP antiserum and IAPP-(8-37), respectively. A combination of somatostatin antiserum with IAPP antiserum or IAPP-(8-37) further enhanced the arginine-stimulated insulin and glucagon secretion compared with effects when the blocking reagents were used individually. These results indicate that endogenously produced IAPP tonally inhibits stimulated insulin, glucagon, and somatostatin secretion. Furthermore, the paracrine effects of IAPP and somatostatin are additive.

In vitro influences between pancreatic adenocarcinoma cells and pancreatic islets.

BACKGROUND: Interactions have been found between exocrine pancreatic adenocarcinoma and islets of Langerhans. Growth of pancreatic adenocarcinoma cells can be regulated by islet hormones such as insulin and somatostatin. Conversely, dysfunction of endocrine pancreas frequently accompanies the exocrine malignancy. The mechanisms underlying these interactions have not been defined. MATERIALS AND METHODS: Human pancreatic adenocarcinoma cells (HPAF cells) were cocultured with isolated rat pancreatic islets in two-compartment wells. HPAF cells and islets cultured in separate wells served as controls. In separate experiments, HPAF cells were incubated with two concentrations of exogenous insulin, including one reflecting the levels of insulin secretion seen in the coculture experiments. RESULTS: Proliferation of HPAF cells was increased by about 50% following a 2- or 5-day incubation with pancreatic islets (P < 0.05). Coculture of HPAF cells and pancreatic islets was associated with a greater reduction in glucose concentrations (P < 0. 01) and an increase in lactate accumulation (P < 0.05) in the culture media. Insulin concentrations in the media were significantly decreased during the first 2-3 days of the coculture incubation (P < 0.05). In contrast, insulin secretion from control islets was not significantly decreased until the fifth day of the experiment. The growth of HPAF cells was stimulated by both concentrations of exogenous insulin (P < 0.05). The insulin-stimulated HPAF cells also showed an enhanced glucose consumption and lactate production (P < 0.05). CONCLUSIONS: Pancreatic islets regulate both growth and glucose metabolism of adjacent exocrine cancer cells. beta-cell-derived insulin may be one of the factors inducing these effects. Insulin release from islet beta-cells is compromised in the presence of exocrine cancer cells.

Effect of islet amyloid polypeptide on somatostatin inhibition of insulin secretion from isolated rat pancreatic islets.

In this study, we investigated the presence of islet amyloid polypeptide (IAPP) in somatostatin cells of rat endocrine pancreas and the effect of exogenous IAPP and somatostatin, separate or combined, on in vitro insulin secretion. By immunocytochemistry, IAPP was found in both B and D cells of rat pancreatic islets. Furthermore, the labeling density of IAPP in D cells was nearly four times higher than in B cells. After a 2-day preincubation in RPMI 1640 (11.1 mM glucose), isolated rat pancreatic islets were exposed to IAPP and/or somatostatin for 90 min in modified Krebs-Ringer bicarbonate (KRB) buffers containing 11.1 or 22.2 mM glucose, or 11.1 mM glucose + 10 mM L-arginine, respectively. At 11.1 mM glucose, insulin secretion was not affected by IAPP and/or somatostatin at concentrations investigated. Insulin response to 22.2 mM glucose was inhibited by exogenous somatostatin. Arginine-stimulated insulin secretion was also inhibited by somatostatin, and the effect was significantly potentiated with additional 10(-5) M IAPP. The study shows that rat pancreatic D cells have higher IAPP density than B cells in the same islets and that IAPP and somatostatin may cooperate on rat pancreatic B cells to regulate the insulin secretion in response to potent stimulation.

Dissociated secretion of islet amyloid polypeptide and insulin in serum-free culture media conditioned by human pancreatic adenocarcinoma cell lines.

CONCLUSION: The cosecretion of insulin and islet amyloid polypeptide (IAPP) is altered when isolated rat pancreatic islets are incubated in culture media conditioned by human pancreatic cancer cells. BACKGROUND: Pancreatic cancer is usually associated with impaired glucose tolerance. This study investigates the tumor-derived influence on beta-cell secretion of pancreatic islets. METHODS: Four conditioned media were prepared from two human pancreatic cancer cell lines (Panc-1 and HPAF), a hamster pancreatic cancer cell line (PC-1), and a fibroblast cell line (Ag1523). Isolated rat pancreatic islets were incubated first in the conditioned media or nonconditioned control medium for 24 h, then in the same kind of media containing 100 microM carbamylcholine for 90 min. Insulin and IAPP secretion were measured by radioimmunoassay. RESULTS: Islets in media conditioned by Panc-1 and HPAF cells demonstrated dissociation of insulin and IAPP secretion. During 24-h incubation, the dissociation was expressed as selectively decreased insulin secretion. With addition of 100 microM carbamylcholine, the dissociation was expressed as normal secretion of insulin and hypersecretion of IAPP. As a result, the IAPP/insulin molar ratios were increased in both groups during both time periods. The islets in PC-1 and Ag1523 media did not show any significant changes in insulin and IAPP secretion.

Trophic effects by epidermal growth factor on duodenal mucosa and exocrine pancreas in rats.

Epidermal growth factor (EGF) is a potent growth factor with possible implications on the regulation of pancreatic secretion and duodenal absorption but also on pancreatic tumor growth. In the present study the growth effect on duodenal mucosa and pancreas by a 14-day continuous infusion of three different doses of EGF (4, 30 and 60 micrograms EGF/kg/24 h) was studied in rats. The EGF content in duodenal mucosa and pancreatic tissue was significantly increased by 30 and 60 micrograms/kg/24 h of EGF while plasma levels were only marginally increased. Neither duodenal mucosal nor pancreatic weights were changed but DNA content in both tissues was increased with the higher EGF doses. Long-term EGF infusion has moderate trophic effect on duodenal mucosa and the pancreas. There is a high tissue uptake of EGF, specially in duodenal mucosa. The hyperplasia seems to be related to tissue levels of EGF but not to plasma levels.

Effects of high-fat diet and cholecystokinin receptor blockade on promotion of pancreatic ductal cell tumors in the hamster.

The mechanism by which high-fat diets potentiate pancreatic cancer is not known, but pancreaticotrophic hormones such as cholecystokinin (CCK) may be involved. The effect of CCK receptor blockade on carcinogenesis during the entire promotion period was investigated in Syrian Golden hamsters fed a high- or low-fat diet and treated with N-nitrosobis(2-oxopropyl)amine (3 x 10 mg/kg at weekly intervals). One-half of the hamsters fed a high-fat diet received the CCK-A receptor antagonist devazepide (25 nmol/kg/hr) for the duration of the experiment. At 39 weeks the incidence of pancreatic malignancies was significantly higher in hamsters fed the high-fat diet than in those fed the low-fat diet (p < 0.05). Tumor incidence was not changed by CCK receptor blockade. Potentiation of pancreatic cancer by a high-fat diet in hamsters does not appear to be influenced by endogenous CCK during the tumor promotion period.