Experimental pancreatic hyperplasia and neoplasia: effects of dietary and surgical manipulation

Gallstones, cholecystectomy and the risk of pancreatic cancer: an updated systematic review and meta-analysis of cohort studies

The effect of gallstones and cholecystectomy on the development of pancreatic cancer has recently prompted many population-based studies. However, the results are controversial. We conducted an updated systematic review and meta-analysis to explore the causality among gallstones, cholecystectomy and pancreatic cancer. Cohort studies published in the PubMed, Web of Science, Embase, and Cochrane Library databases up to May 2023 were retrieved. Pooled relative risks (RRs) and 95% confidence intervals (CIs) were analyzed using a random-effects model. We screened 1391 articles and included 16 studies. Gallstones were not associated with an increased risk of pancreatic cancer ( P  = 0.082), with only the Asian population ( P  = 0.011) showing an increased risk in the subgroup analysis. A markedly higher risk of pancreatic cancer was observed among patients with cholecystectomy (RR = 1.23; 95% CI, 1.07-1.41; P  = 0.004; I 2  = 74.4%). The association remained significant in the Asian population ( P  = 0.004), in the subgroup analyses stratified by sex, lag period, and time interval since cholecystectomy, and when the models were adjusted for diabetes, smoking, and BMI. Interestingly, cholecystectomy due to gallstones (RR = 1.30; 95% CI, 1.14-1.48; P  < 0.001; I 2  = 30.8%), rather than for unspecified reasons ( P  = 0.116), markedly increased the risk of pancreatic cancer. In conclusion, cholecystectomy due to gallstones, rather than gallstone formation, conferred an increased risk for pancreatic cancer. There was a higher risk for the Asian population for both gallstones and cholecystectomy.

The Evaluation of Gallstone Disease in the Year Before Pancreatic Cancer Diagnosis

INTRODUCTION

Patients with pancreatic cancer can present with a variety of insidious abdominal symptoms, complicating initial diagnosis. Early symptoms of pancreatic cancer often mirror those associated with gallstone disease, which has been demonstrated to be a risk factor for this malignancy. This study aims to compare the incidence of gallstone disease in the year before diagnosis of pancreatic ductal adenocarcinoma (PDAC) as compared to the general population, and evaluate the association of gallstone disease with stage at diagnosis and surgical intervention.

METHODS

Patients with PDAC were identified from SEER-Medicare (2008-2015). The incidence of gallstone disease (defined as cholelithiasis, cholecystitis and/or cholecystectomy) in the 1 year before cancer diagnosis was compared to the annual incidence in an age-matched, sex-matched, and race-matched noncancer Medicare cohort.

RESULTS

Among 14,654 patients with PDAC, 4.4% had gallstone disease in the year before cancer diagnosis. Among the noncancer controls (n = 14,654), 1.9% had gallstone disease. Both cohorts had similar age, sex and race distributions. PDAC patients with gallstone disease were diagnosed at an earlier stage (stage 0/I-II, 45.8% versus 38.1%, P < 0.0001) and a higher proportion underwent resection (22.7% versus 17.4%, P = 0.0004) compared to patients without gallstone disease.

CONCLUSIONS

In the year before PDAC diagnosis, patients present with gallstone disease more often than the general population. Improving follow-up care and differential diagnosis strategies may help combat the high mortality rate in PDAC by providing an opportunity for earlier stage of diagnosis and earlier intervention.

Suppression of Ov-grn-1 encoding granulin of Opisthorchis viverrini inhibits proliferation of biliary epithelial cells

Multistep processes likely underlie cholangiocarcinogenesis induced by chronic infection with the fish-borne liver fluke, Opisthorchis viverrini. One process appears to be cellular proliferation of the host bile duct epithelia driven by excretory-secretory (ES) products of this pathogen. Specifically, the secreted growth factor Ov-GRN-1, a liver fluke granulin, is a prominent component of ES and a known driver of hyper-proliferation of cultured human and mouse cells in vitro. We show potent hyper-proliferation of human cholangiocytes induced by low nanomolar levels of recombinant Ov-GRN-1 and similar growth produced by low microgram concentrations of ES products and soluble lysates of the adult worm. To further explore the influence of Ov-GRN-1 on the flukes and the host cells, expression of Ov-grn-1 was repressed using RNA interference. Expression of Ov-grn-1 was suppressed by 95% by day 3 and by ~100% by day 7. Co-culture of Ov-grn-1 suppressed flukes with human cholangiocyte (H-69) or human cholangiocarcinoma (KKU-M214) cell lines retarded cell hyper-proliferation by 25% and 92%, respectively. Intriguingly, flukes in which expression of Ov-grn-1 was repressed were less viable in culture, suggesting that Ov-GRN-1 is an essential growth factor for survival of the adult stage of O. viverrini, at least in vitro. To summarize, specific knock down of Ov-grn-1 reduced in vitro survival and capacity of ES products to drive host cell proliferation. These findings may help to contribute to a deeper understanding of liver fluke induced cholangiocarcinogenesis.

Pancreatic cancer: a review of the evidence on causation

Pancreatic cancer kills more than 250,000 people each year worldwide and has a poor prognosis. The aim of this article is to critically review the epidemiologic evidence for exposures that may either increase or decrease the risk. A Medline search was performed for epidemiologic studies and reviews published up to April 2007. Consistent evidence of a positive association was found for family history and cigarette smoking. Many studies documented a positive association with diabetes mellitus and chronic pancreatitis, although the etiologic mechanisms are unclear. Other associations were detected, but the results were either inconsistent or from few studies. These included positive associations with red meat, sugar, fat, body mass index, gallstones, and Helicobacter pylori, and protective effects of increasing parity, dietary folate, aspirin, and statins. There was no evidence linking alcohol or coffee consumption with an increased risk of pancreatic cancer. The associations with many exposures need to be clarified from further epidemiologic work in which there is both precise measurement of risk factors, adjustment for potential confounders, and, for dietary studies, information recorded on the method of food preparation and pattern of consumption. Such work is important to reduce the incidence of this fatal disease.

Gene expression profiling defined pathways correlated with fibroblast cell proliferation induced by Opisthorchis viverrini excretory/secretory product

AIM: To investigate the mechanism of fibroblast cell proliferation stimulated by the Opisthorchis viverrini excretory/secretory (ES) product.

METHODS: NIH-3T3, mouse fibroblast cells were treated with O. viverrini ES product by non-contact co-cultured with the adult parasites. Total RNA from NIH-3T3 treated and untreated with O. viverrini was extracted, reverse transcribed and hybridized with the mouse 15K complementary DNA (cDNA) array. The result was analyzed by ArrayVision version 5 and GeneSpring version 5 softwares. After normalization, the ratios of gene expression of parasite treated to untreated NIH-3T3 cells of 2-and more-fold upregulated was defined as the differentially expressed genes. The expression levels of the signal transduction genes were validated by semi-quantitative SYBR-based real-time RT-PCR.

RESULTS: Among a total of 15 000 genes/ESTs, 239 genes with established cell proliferation-related function were 2 fold-and more-up-regulated by O. viverrini ES product compared to those in cells without exposure to the parasitic product. These genes were classified into groups including energy and metabolism, signal transduction, protein synthesis and translation, matrix and structural protein, transcription control, cell cycle and DNA replication. Moreover, the expressions of serine-threonine kinase receptor, receptor tyrosine kinase and collagen production-related genes were up-regulated by O. viverrini ES product. The expression level of signal transduction genes; pkC, pdgfrα, jak 1, eps 8, tgfβ 1i4, strap and h ras measured by real-time RT-PCR confirmed their expression levels to those obtained from cDNA array. However, only the up-regulated expression of pkC, eps 8 and tgfβ 1i4 which are the downstream signaling molecules of either epidermal growth factor (EGF) or transforming growth factor-β (TGF-β) showed statistical significance (P < 0.05).

CONCLUSION: O. viverrini ES product stimulates the significant changes of gene expression in several functional categories and these mainly include transcripts related to cell proliferation. The TGF-β and EGF signal transduction pathways are indicated as the possible pathways of O. viverrini-driven cell proliferation.

Expression of cyclooxygenase-2 in cholangiocarcinoma: correlation with clinicopathological features and prognosis

BACKGROUND AND AIMS

No information is available on the nature of the correlation between cyclooxygenase-2 (COX-2) expression and the clinicopathological features and prognosis of cholangiocarcinoma (CC). The goal of the present study was to determine the possible roles and clinical significance of COX-2 expression in CC.

METHODS

We investigated the immunohistochemical expression of COX-2 in 102 patients with CC with respect to clinicopathological characteristics, namely evidence of Clonorchis sinensis infection, proliferation index (PI, assessed by Ki-67 expression), apoptotic index (AI, assessed by TUNEL stain), and microvessel density (MVD, assessed by CD34 expression). Evidence of C. sinensis infection was assessed by the microscopic examination of stools for C. sinensis ova, serological testing (ELISA), and the detection of peripheral bile duct dilations by imaging studies.

RESULTS

An immunohistochemical investigation demonstrated the immunolabeling of tumor cells, mainly in the cytoplasmic and perinuclear regions, in 53 (52%) of the 102 patients with CC. No significant differences were found in terms of age, sex, tumor differentiation, involvement of the resection margin, presence of lymph nodes or liver metastases, or in pTNM stage between COX-2 positive and COX-2 negative patients. However, evidence of C. sinensis infection was more common in COX-2 positive patients (P < 0.05). No significant differences were found for PI, AI, MVD, or cumulative survival between COX-2 positive and COX-2 negative patients.

CONCLUSION

Clonorchis sinensis infection is related to aberrant COX-2 expression in patients with CC. However, COX-2 expression is not related to clinical outcome in CC patients.

Experimental animal models of pancreatic carcinogenesis and metastasis

Pancreatic cancer is a lethal disease characterized by early metastasis, local invasion, and resistance to conventional therapies. To understand its etiology and eventually make prevention of it possible and effective, appropriate carcinogenesis models will certainly help us understand the effects of environmental and genetic elements on pancreatic carcinogenesis. The development of new treatment strategies to control cancer metastasis is of immediate urgency. Fulfillment of this task relies on our knowledge of the cellular and molecular biology of pancreatic cancer metastasis and the availability of biologically and clinically relevant model systems. Many of the existing pancreatic cancer carcinogenesis and metastasis animal models are described in this review. The advantages and disadvantages of each model and their clinical implications are discussed, and special attention is focused on experimental therapeutic strategies targeting pancreatic cancer metastasis.

Etiology of pancreatic cancer, with a hypothesis concerning the role of N-nitroso compounds and excess gastric acidity

In the United States, pancreatic cancer is the fourth most frequent cause of cancer death in males as well as females, after lung, prostate or breast, and colorectal cancer. Each year, approximately 30 000 Americans are diagnosed with pancreatic cancer and about the same number die of it. Germline mutations in a few genes including p16 and BRCA2 have been implicated in a small fraction of cases, as has chronic pancreatitis. The one established risk factor for pancreatic cancer is cigarette smoking: current smokers have two to three times the risk of nonsmokers. Studies of dietary factors have not been entirely consistent but do suggest associations of higher risk with consumption of smoked or processed meats or with animal foods in general and lower risk with consumption of fruits and vegetables. Colonization by Helicobacter pylori appears to increase risk, and a history of diabetes mellitus may also increase risk. The purpose of this epidemiologic review is to consider the possibility that risk of pancreatic cancer is increased by factors associated with pancreatic N-nitrosamine or N-nitrosamide exposures and with chronic excess gastric or duodenal acidity. Host genetic variation in inflammatory cytokine mechanisms may also be involved in this process. Many features of the evidence bearing on the pathophysiology of pancreatic cancer appear to support connections with N-nitroso compounds and with gastric acidity.

Exploring environmental causes of altered ras effects: fragmentation plus integration?

Mutations in ras genes are the most common abnormality of oncogenes in human cancer and a major example of activation by point mutation. Experimental and epidemiological studies support the notion that Ki-ras activation and expression may be chemically related. We discuss the potential role of several environmental compounds in the induction or promotion of ras mutations in humans, with a focus on exocrine pancreatic cancer, the human tumor with the highest prevalence at diagnosis of Ki-ras mutations. Organochlorine compounds, organic solvents, and coffee compounds may play an indirect role in causing Ki-ras mutations, rather than as direct inducers of the mutations. Although for some organochlorine compounds the induction of point mutations in ras oncogenes cannot be excluded, it seems more likely that the effects of these compounds are mediated through nongenomic or indirectly genotoxic mechanisms of action. Organic solvents also may act via enzymatic induction of ras mutagens or by providing a proliferation advantage to ras-mutated cell clones. In exocrine pancreatic cancer, caffeine, other coffee compounds, or other factors with which coffee drinking is associated could modulate Ki-ras activation by interfering with DNA repair, cell-cycle checkpoints, and apoptosis. Asbestos, cigarette smoking, and some dietary factors also may be involved in the initiation or the promotion of Ki-ras mutations in lung and colon cancers. Further development of the mechanistic scenarios proposed here could contribute to a meaningful integration of biological, clinical, and environmental knowledge on the causes of altered ras effects.

Liver fluke-associated cholangiocarcinoma

BACKGROUND

Infection with liver flukes has been reported to be associated with bile duct malignancy.

METHODS

The review is based on a literature search (Medline) and, in some cases, direct contact with authors or principal investigators.

RESULTS

A large body of evidence indicates that Opisthorchis viverrini is a definite cause of human cholangiocarcinoma, whereas Clonorchis sinensis is a probable cause. The evidence regarding Opisthorchis felineus is insufficient to assess its role in carcinogenesis. Possible mechanisms of carcinogenesis include chronic irritation, nitric oxide formation, intrinsic nitrosation and activation of drug-metabolizing enzymes. Early detection of bile duct malignancy is difficult and not clinically available at present, although cholangiocarcinoma-associated soluble antigen has been reported in an experimental study to be a useful early marker of cancer development. Long-term survival after surgical treatment of liver fluke-associated cancer is similar to that reported in patients without liver fluke infestation.

CONCLUSION

Liver fluke-associated cholangiocarcinoma is still a health problem in developing countries. Mechanisms of carcinogenesis should be explored further in order to reduce the impact of this disease.

Pancreatic cancer after remote peptic ulcer surgery

BACKGROUND

Peptic ulcer surgery may carry an increased risk for pancreatic cancer development. Molecular analysis of K-ras codon 12, frequently mutated in conventional pancreatic cancers, might provide insight into the aetiological mechanisms.

METHODS

The relative risk of pancreatic cancer was computed by multivariate and person-year analysis in a cohort of 2633 patients who had undergone gastrectomy. Lung cancer risk was analysed as an indirect means of assessing smoking behaviour. K-ras codon 12 mutational analysis was performed on 15 postgastrectomy pancreatic cancers.

RESULTS

There was an overall increased risk of pancreatic carcinoma of 1.8 (95% confidence interval, 1.3 to 2.6) five to 59 years postoperatively, which gradually increased to 3.6 at 35 years or more after surgery (chi(2) test for trend, p < 0.05). Multivariate analysis indicated that parameters other than postoperative interval did not influence the risk. Lung cancer risk was significantly increased after surgery, but no time trend was observed. The spectrum and prevalence of K-ras codon 12 mutations were comparable to conventional pancreatic cancer.

CONCLUSIONS

Remote partial gastrectomy is associated with an increased risk of pancreatic cancer. Postgastrectomy and non-postgastrectomy pancreatic cancers may share similar aetiological factors, such as smoking. However, the neoplastic process in patients who have undergone gastrectomy appears to be accelerated by factors related to the surgery itself.

Gallstones, cholecystectomy, and the risk for developing pancreatic cancer

We examined the relation between gallstones, cholecystectomy, and the development of pancreatic cancer in the Nurses' Health Study and the Health Professionals Follow-up Study. Among 104,856 women and 48,928 men without cancer at baseline, we documented 349 cases of pancreatic cancer during up to 16 years of follow-up. Participants were classified according to a history of gallstones or cholecystectomy. The age-adjusted relative risk of pancreatic cancer following cholecystectomy or diagnosis of gallstones was 1.31 (95% CI, 0.93-1.83). However, adjustment for other pancreatic cancer risk factors attenuated the association (RR=1.11, 95% CI, 0.78-1.56); this risk did not increase with increasing time following cholecystectomy or gallstones. Gallstones or cholecystectomy do not appear to be significant risk factors for pancreatic cancer.

A novel, clinically relevant animal model of metastatic pancreatic adenocarcinoma biology and therapy

In this study, we report a metastatic model of Panc02 murine pancreatic adenocarcinoma. Parental Panc02 cells were orthotopically implanted into the pancreas of syngeneic C57BL/6 mice. Tumor cells were isolated from liver micrometastases 90 d after tumor implantation and established as a culture (Panc02-H1). The Panc02-H1 cells were then implanted into the pancreas of mice. Liver metastases were then collected and established as Panc02-H2 cells. This process was repeated until the Panc02-H7 cell line was established. These cells were extremely aggressive after implantation as manifested by progressive growth in the pancreas, peritoneal dissemination, and distant metastasis to multiple organs, including the liver and lungs. Moreover, Panc02-H7 cells expressed the inducible nitric oxide synthase gene at a very low level in culture and produced highly vascularized tumors having a large number of infiltrating macrophages. Collectively, this model system should be a valuable tool for investigating the molecular mechanisms governing pancreatic cancer growth and metastasis and exploring potential treatment modalities for this disease.

Mouse models of metastatic pancreatic adenocarcinoma

Pancreatic adenocarcinoma is a deadly disease. Its etiology is unknown, and metastatic disease kills the majority of patients who have it. Effective prevention is clearly the ultimate goal for eradicating this disease provided that the effects of environmental and genetic elements on pancreatic cancer development are fully understood. Currently, it appears that the control of pancreatic cancer metastasis is of immediate urgency. Fulfillment of this difficult task relies on knowledge of the cellular and molecular biology of metastasis. The use of relevant animal models will help define each aspect of this complicated process.

Risk of pancreatic cancer after cholecystectomy: a cohort study in Sweden

BACKGROUND

Although some experimental studies have indicated that cholecystectomy may increase the risk of pancreatic cancer, data from epidemiological studies are conflicting.

AIMS

We conducted a register based retrospective cohort study to explore the relationship between cholecystectomy and pancreatic cancer.

SUBJECTS

The cohort included 87 263 men and 181 049 women with a documented cholecystectomy for cholelithiasis between 1965 and 1997.

METHODS

By record linkage to the nationwide and virtually complete registers of Cancer, Emigration, and Causes of Death, the cohort was followed up until the occurrence of any cancer, emigration, death, or the end of follow up, 31 December 1997, whichever came first. Relative risk was estimated by standardised incidence ratio (SIR) using the Swedish nationwide sex, age, and calendar year specific cancer incidence rates as reference.

RESULTS

During the period of observation, 1053 cases of pancreatic cancer were found, among which 231 (22%) occurred within 12 months after operation. After excluding cases and person years accrued during the first two years of follow up, we observed a non-significant 6% excess risk for pancreatic cancer (95% confidence interval (CI) -2 to 14%). The relative risk did not increase with increasing follow up duration, with a SIR equal to 0.98 (95% CI 0.79-1.20) 20 years or more after operation. Patients with a comorbidity of diabetes or chronic pancreatitis had higher relative risks (SIR=1.79, 95% CI 1.39-2.28; SIR=3.17, 95% CI 1.37-6.24, respectively). After excluding patients with recorded diabetes or chronic pancreatitis, the relative risk was close to unity (SIR=1.01, 95% CI 0.94-1.09).

CONCLUSIONS

Our findings do not support the hypothesis that cholecystectomy increases the subsequent risk of pancreatic cancer.

Autocrine and paracrine signaling through neuropeptide receptors in human cancer

Autocrine and paracrine signaling leading to stimulation of tumor cell growth is a common theme in human cancers. In addition to polypeptide growth factors such as EGF family members which signal through receptor tyrosine kinases, accumulating evidence supports the autocrine and paracrine involvement of specific neuropeptides with defined physiologic actions as neurotransmitters and gut hormones in lung, gastric, colorectal, pancreatic and prostatic cancers. These neuropeptides, including gastrin-releasing peptide, neuromedin B, neurotensin, gastrin, cholecystokinin and arginine vasopressin bind seven transmembrane-spanning receptors that couple to heterotrimeric G proteins. Studies with human small cell lung cancer (SCLC) cells support a requirement for balanced signaling through G(q) and G(12/13) proteins leading to intracellular Ca2+ mobilization, PKC activation and regulation of the ERK and JNK MAP kinase pathways. While specific neuropeptide antagonists offer promise for interrupting the single neuropeptide autocrine systems operating in pancreatic and prostatic cancers, SCLC is exemplified by multiple, redundant neuropeptide autocrine systems such that tumor growth cannot be inhibited with a single specific antagonist. However, a novel class of neuropeptide derivatives based on the substance P sequence have been defined that exhibit broad specificity for neuropeptide receptors and induce apoptosis in SCLC by functioning as biased agonists that stimulate discordant signal transduction. Thus, interruption of autocrine and paracrine neuropeptide signaling with specific antagonists or broad-spectrum biased agonists offer promising new therapeutic approaches to the treatment of human cancers.

Synchronous or metachronous double cancers of the pancreas and other organs: report on 12 cases

Pancreatic carcinoma carries a poor prognosis, especially invasive ductal carcinoma of the pancreas. This retrospective study describes the results of the treatment and prognosis for double cancers in which cancer of the pancreas was associated with malignancies in other organs in 12 patients who were diagnosed and treated at Kurume University Hospital. The patients included 4 women and 8 men, with an average age of 67 years. Of the 12 tumors, 7 were metachronous pancreatic cancers which occurred after resections of other organ malignancies. Five patients had synchronous double cancers, one of whom was diagnosed to have gastric cancer on admission. Two other patients of this group were diagnosed to have lung cancer, while the remaining 2 patients suffered from colon cancer. By the time pancreatic cancer was diagnosed, gastrectomies had been performed in 7 patients for either gastric cancer or ulcers. In addition, one patient underwent a hysterectomy for uterine carcinoma and another received a low anterior resection for rectal carcinoma. Four of 5 patients in the synchronous group had nonresectable tumors and a palliative bypass operation was performed in 2 of these patients. Six patients who had metachronous double cancers died because of pancreatic cancer recurrence or metastases. We conclude that the prognosis of double cancers, where cancer of the pancreas is associated with other organ malignancies, primarily depends on the prognosis of the pancreatic carcinoma, and the present study suggests the necessity of long-term follow-up examinations for gastrectomy patients in order to make an early diagnosis of pancreatic cancer.

Risk factors for pancreatic cancer: a case-control study based on direct interviews

The etiology of pancreatic cancer is poorly understood, partly because of the inconsistency of findings among case-control studies of pancreatic cancer. Because of the unfavorable prognosis for pancreatic cancer, many case-control studies have been based largely on interviews with next of kin, who are known to report less reliable information on potential risk factors than original respondents. The purpose of this study was to estimate the effects of speculative risk factors such as dietary/nutritional factors and alcohol drinking, as well as those of established risk factors such as cigarette smoking, diabetes mellitus, and family history of pancreatic cancer, on pancreatic cancer risk based solely on direct interviews. This investigation was a population-based case-control study of pancreatic cancer diagnosed in Atlanta (GA), Detroit (MI), and ten New Jersey counties from August 1986 through April 1989. Direct interviews were conducted with 526 incident cases and 2,153 population controls. This study revealed a significant interaction between body mass index and caloric intake that was consistent by both race and gender. Subjects with elevated body mass index and caloric intake had increased risk, whereas those with elevated values for one of these factors but not the other experienced no increased risk. This finding suggests that energy balance may play a major role in pancreatic carcinogenesis. Diabetes mellitus was also a risk factor for pancreatic cancer, as well as a possible complication of the tumor. Our data are consistent with a key role for hyperinsulinemia in pancreatic carcinogenesis, particularly among non-diabetics with an elevated body mass index. A three-fold risk of pancreatic cancer among first-degree relatives of affected individuals was apparent. An increased risk also was associated with a family history of colon, endometrial, ovary, and breast cancer, suggesting a possible link to hereditary non-polyposis colon cancer. Our findings support a causal role for cigarette smoking in pancreatic carcinogenesis. Alcohol drinking at levels typically consumed by the general population of the United States did not appear to be a risk factor for pancreatic cancer, although heavy drinking may be related to risk, particularly in blacks.

Gallstones, cholecystectomy and risk of cancers of the liver, biliary tract and pancreas

To examine the association between gallstones and cholecystectomy, we conducted a nationwide population-based cohort study in Denmark. Patients with a discharge diagnosis of gallstones from 1977 to 1989 were identified from the Danish National Registry of Patients and followed up for cancer occurrence until death or the end of 1993 by record linkage to the Danish Cancer Registry. Included in the cohort were 60 176 patients, with 471 450 person-years of follow-up. Cancer risks were estimated by standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) stratified by years of follow-up and by cholecystectomy status. Among patients without cholecystectomy, the risks at 5 or more years of follow-up were significantly elevated for cancers of liver (SIR = 2.0, CI = 1.2-3.1) and gallbladder (SIR = 2.7, CI = 1.5-4.4) and near unity for cancers of extrahepatic bile duct (SIR = 1.1), ampulla of Vater (SIR = 1.0) and pancreas (SIR = 1.1). The excess risk of liver cancer was seen only among patients with a history of hepatic disease. Among cholecystectomy patients, the risks at 5 or more years of follow-up declined for cancers of liver (SIR = 1.1) and extrahepatic bile duct (SIR = 0.7), but were elevated for cancers of ampulla of Vater (SIR = 2.0, CI = 1.0-3.7) and pancreas (SIR = 1.3, CI = 1.1-1.6). These findings confirm that gallstone disease increases the risk of gallbladder cancer, whereas cholecystectomy appears to increase the risk of cancers of ampulla of Vater and pancreas. Further research is needed to clarify the carcinogenic risks associated with gallstones and cholecystectomy and to define the mechanisms involved.

Dietary and nutritional factors and pancreatic cancer: a case-control study based on direct interviews

BACKGROUND

The relationship between diet and pancreatic cancer remains unclear. In this study, we assessed the role of diet and nutrition as risk factors for pancreatic cancer, using data obtained from direct interviews only, rather than data from less reliable interviews with next of kin. We evaluated whether dietary factors could explain the higher incidence of pancreatic cancer experienced by black Americans compared with white Americans.

METHODS

We conducted a population-based case-control study of pancreatic cancer diagnosed in Atlanta (GA), Detroit (MI), and 10 New Jersey counties from August 1986 through April 1989. Reliable dietary histories were obtained for 436 patients and 2003 general-population control subjects aged 30-79 years.

RESULTS

Obesity was associated with a statistically significant 50%-60% increased risk of pancreatic cancer that was consistent by sex and race. Although the magnitude of risk associated with obesity was identical in blacks and whites, a higher percentage of blacks were obese than were whites (women: 38% versus 16%; men: 27% versus 22%). A statistically significant positive trend in risk was observed with increasing caloric intake, with subjects in the highest quartile of caloric intake experiencing a 70% higher risk than those in the lowest quartile. A statistically significant interaction between body mass index (weight in kg/height in m2 for men and weight in kg/height in m1.5 for women) and total caloric intake was observed that was consistent by sex and race. Subjects in the highest quartile of both body mass index and caloric intake had a statistically significant 180% higher risk than those in the lowest quartile.

CONCLUSIONS

Obesity is a risk factor for pancreatic cancer and appears to contribute to the higher risk of this disease among blacks than among whites in the United States, particularly among women. Furthermore, the interaction between body mass index and caloric intake suggests the importance of energy balance in pancreatic carcinogenesis.

Synchronous double cancers of the remnant stomach and pancreas: report of a case

We present here in the case of a 75-year-old man who developed synchronous double cancers of the remnant stomach and pancreas 12 years after undergoing distal gastrectomy for gastric carcinoma. The patient was referred to our hospital in March, 1993, with a provisional diagnosis of carcinoma of the remnant stomach. Laboratory data on admission showed an abnormal level of CA19-9 (116.1 U/ml) and positive occult blood in the stools. An upper gastrointestinal series and gastroendoscopy demonstrated an ulcerative polypoid tumor in the gastric stump proximal to the gastroduo-denostomy anastomosis, and a biopsy confirmed the findings of mucinous adenocarcinoma. Abdominal computed tomography (CT) scan revealed a low-density nodule anterior to the abdominal aorta, suggestive of a nodal metastasis. A laparotomy was performed which also disclosed a low-density mass located within the head of the pancreas. The patient was subsequently diagnosed as having double carcinomas of the remnant stomach and pancreas, and total gastrectomy and pancreatoduodenectomy were carried out. The histologic sections from the remnant stomach showed mucinous adenocarcinoma, whereas those from the pancreas showed tubular adenocarcinoma. Double carcinomas in this association are extremely rare and this case may in fact be the first observation of synchronous double cancers of the remnant stomach and pancreas.

A prospective study of pancreatic cancer in the elderly

Risk factors for pancreatic cancer were examined in a cohort study of 13,979 residents of a retirement community. After 9 years of follow-up, 65 incident cases of pancreatic cancer were identified. An increased risk of pancreatic cancer was associated with a history of diabetes and cholecystectomy. Higher intake of vegetables, fruits, dietary beta-carotene, and vitamin C were each associated with a reduced risk of pancreatic cancer, although none of these associations was statistically significant. Risk of pancreatic cancer decreased with increasing tea consumption but was unrelated to coffee consumption. No strong or consistent association was seen between either smoking or alcohol consumption and risk of pancreatic cancer, but a consistent and significant increase in risk followed cholecystectomy.