Epidemiology of and risk factors for pancreatic cancer

Epidemiology, Treatment, and Outcome of Pancreatic Squamous Cell Carcinoma and Pancreatic Adenocarcinoma: A Propensity Score-Matching Analysis Based on SEER-Database

Background: Pancreatic squamous cell carcinoma (PSCC) is a rare pancreatic malignancy compared to most common pancreatic adenocarcinoma (PAC). Aims: To analyze the prognostics factors of PSCC and compare PAC with PSCC in demographic patterns, clinicopathologic characteristics and treatment modalities. Methods: Data of PSCC and PAC patients from January 1, 2004 to December 31, 2015 were extracted from Surveillance, Epidemiology and End Results (SEER) database for case-control study. Kaplan-Meier method and Cox proportional hazards analysis were used in survival analysis. A 1:3 propensity-score matching (PSM) was performed to compare the overall survival (OS) and cancer specific survival (CSS) between PAC and PSCC in each variable. Results: PAC patients (n = 38 968) and PSCC patients (n = 124) were analyzed. After PSM, 372 PAC patients and 124 PSCC patients were obtained. PSCC tends to happen to elders, white and female with a predilection site of pancreatic head, followed by tail, then body. PSCC have a higher proportion to be poorly differentiated and metastatic when diagnosed. The prognosis of PSCC patients was significantly worse than PAC patients in both univariate and multivariate analyses. Surgery and chemotherapy were independent prognostic factors for PSCC. Conclusions: PSCC patients were identified associated with a worse prognosis than PAC patients. PSCC tend to be poorly differentiated and more easily to be metastatic. Surgery and chemotherapy may be effective therapies to improve the OS of PSCC significantly.

Percutaneous palliation of pancreatic head cancer: randomized comparison of ePTFE/FEP-covered versus uncovered nitinol biliary stents

The purpose of this study was to compare the clinical effectiveness of expanded polytetrafluoroethylene/fluorinated-ethylene-propylene (ePTFE/FEP)-covered stents with that of uncovered nitinol stents for the palliation of malignant jaundice caused by inoperable pancreatic head cancer. Eighty patients were enrolled in a prospective randomized study. Bare nitinol stents were used in half of the patients, and ePTFE/FEP-covered stents were used in the remaining patients. Patency, survival, complications, and mean cost were calculated in both groups. Mean patency was 166.0 ± 13.11 days for the bare-stent group and 234.0 ± 20.87 days for the covered-stent group (p = 0.007). Primary patency rates at 3, 6, and 12 months were 77.5, 69.8, and 69.8% for the bare-stent group and 97.5, 92.2, and 87.6% for the covered-stent group, respectively. Mean secondary patency was 123.7 ± 22.5 days for the bare-stent group and 130.3 ± 21.4 days for the covered-stent group. Tumour ingrowth occurred exclusively in the bare-stent group in 27.5% of cases (p = 0.002). Median survival was 203.2 ± 11.8 days for the bare-stent group and 247.0 ± 20 days for the covered-stent group (p = 0.06). Complications and mean cost were similar in both groups. Regarding primary patency and ingrowth rate, ePTFE/FEP-covered stents have shown to be significantly superior to bare nitinol stents for the palliation of malignant jaundice caused by inoperable pancreatic head cancer and pose comparable cost and complications. Use of a covered stent does not significantly influence overall survival rate; nevertheless, the covered endoprosthesis seems to offer result in fewer reinterventions and better quality of patient life.

Alcohol intake and pancreatic cancer risk: a pooled analysis of fourteen cohort studies

BACKGROUND

Few risk factors have been implicated in pancreatic cancer etiology. Alcohol has been theorized to promote carcinogenesis. However, epidemiologic studies have reported inconsistent results relating alcohol intake to pancreatic cancer risk.

METHODS

We conducted a pooled analysis of the primary data from 14 prospective cohort studies. The study sample consisted of 862,664 individuals among whom 2,187 incident pancreatic cancer cases were identified. Study-specific relative risks and 95% confidence intervals were calculated using Cox proportional hazards models and then pooled using a random effects model.

RESULTS

A slight positive association with pancreatic cancer risk was observed for alcohol intake (pooled multivariate relative risk, 1.22; 95% confidence interval, 1.03-1.45 comparing >or=30 to 0 grams/day of alcohol; P value, test for between-studies heterogeneity=0.80). For this comparison, the positive association was only statistically significant among women although the difference in the results by gender was not statistically significant (P value, test for interaction=0.19). Slightly stronger results for alcohol intake were observed when we limited the analysis to cases with adenocarcinomas of the pancreas. No statistically significant associations were observed for alcohol from wine, beer, and spirits comparing intakes of >or=5 to 0 grams/day. A stronger positive association between alcohol consumption and pancreatic cancer risk was observed among normal weight individuals compared with overweight and obese individuals (P value, test for interaction=0.01).

DISCUSSION

Our findings are consistent with a modest increase in risk of pancreatic cancer with consumption of 30 or more grams of alcohol per day.

Overview of the epidemiology of pancreatic cancer focusing on the JACC Study

BACKGROUND: The objective of this article was to overview the epidemiology of pancreatic cancer. We summarize the results of the Japan Collaborative Cohort Study (JACC Study) and some previous studies.

METHODS: References were mainly in a Medline search through Pub Med database. In addition, 3 papers about the JACC Study were quoted.

RESULTS : In the JACC Study, the standardized mortality ratio of pancreatic cancer was 0.97 in females and 0.84 in males. Diabetes mellitus (DM) has increased the risk for pancreatic cancer in many studies. In the JACC Study, DM had a risk for pancreatic cancer in males (hazard ratio = 2.12). Cigarette smoking has been associated with pancreatic cancer in many studies. In the JACC Study, the hazard ratio for current smokers was 1.6 in males, and 1.7 in females. The ratio was 3.3 who smoked 40+ cigarettes/day in males. In the JACC Study, alcohol intake was not associated with pancreatic cancer. These results are consistent with the other studies. Coffee consumption has not been associated with pancreatic cancer in many studies. In the JACC Study, the hazard ratio significantly increased to 3.19 among men who consumed 4+ cups of coffee per day. The relationships between diet /nutrition and pancreatic cancer are not clear in many studies.

CONCLUSION: The relation between smoking and pancreatic cancer is most consistently described. A further analysis of the relationships between family history, hormonal factors in females, dietary and nutritional factors, obesity, physical activity and pancreatic cancer is necessary.

Pancreatic tumors in patients with lung malignancies: a spectrum of clinicopathologic considerations

OBJECTIVES

Lung cancer and pancreatic cancer are the most lethal tobacco-associated malignancies. To elucidate possible clinical interrelationships, the authors reviewed the clinicopathologic characteristics of patients treated for both pulmonary and pancreatic neoplasms.

METHODS

Patients presenting with a potentially resectable pancreatic mass and a diagnosis of metachronous malignant neoplasm of the lung were studied by retrospective chart audit and review of histopathologic material.

RESULTS

Seven patients were identified over 6 years, representing five different clinical entities: metachronous presence of lung cancer and pancreatic cancer (n = 3), lung cancer metastatic to the pancreas (n = 1), lung cancer with a benign pancreatic neoplasm (n = 1), periampullary cancer metastatic to the lung (n = 1), and malignant melanoma metastatic to both lung and pancreas (n = 1). A tobacco history was present in all patients but one. Primary treatment modality was complete resection of isolated sites whenever feasible (lung resection, n = 6; pancreatic resection, n = 5). In four cases, a differential diagnosis of adenocarcinomas of both lung and pancreas was obtained after cytokeratin (CK) 7 and CK 20 immunohistochemistry. All patients with evidence of nodal or visceral metastasis from either primary site (n = 4) died within 5 to 9 months after the last operation. Three of four patients who had undergone resection of both pulmonary and pancreatic tumors were alive between 17 and 67 months after the last operation. All three survivors had presented with early disease stages and/or a protracted course (diagnostic interval, 16-66 months).

CONCLUSIONS

Our experience with neoplastic conditions that can involve lungs and pancreas metachronously may be useful to the clinician who is confronted with a similar situation. If therapeutic decision-making depends on differential diagnostic analysis, examination of CK 20 expression appears to be helpful. Although biologically favorable circumstances are rarely present, long-term survival seems possible after complete operative treatment in selected patients with early-stage disease.

Relationship between depression and pancreatic cancer in the general population

OBJECTIVE

Prior research suggesting a relationship between pancreatic cancer and depression conducted on clinical populations has been subject to recall bias. We reexamined this association using longitudinal population-based data.

METHODS

This was a retrospective cohort study using longitudinal insurance claims data.

RESULTS

Men with mental disorders were more likely to develop pancreatic cancer than those without psychiatric claims (odds ratio 2.4, confidence interval 1.15-4.78). Depression more commonly preceded pancreatic cancer than it did other gastrointestinal malignancies (odds ratio 4.6, confidence interval 1.07-19.4) or all other cancers (odds ratio 4.1, confidence interval 1.05-16.0).

CONCLUSIONS

Depression and pancreatic cancer are associated in the general population.

Histopathologic changes induced by cellophane wrapping of the pancreas are unaffected by cigarette smoke exposure in hamsters

This study tests whether exposure to cigarette smoke alone or combined with cellophane wrapping of the pancreas increases the development of microscopic abnormalities in the pancreas of Syrian golden hamsters. Ninety hamsters were randomly divided into 4 groups. Thirty-five hamsters were exposed to 3 continuous hours of cigarette smoke daily for 3 months following celiotomy to cellophane wrap the gastric lobe of the pancreas (group 1). Thirty-two hamsters were not exposed to continuous cigarette smoke and had the wrap surgery alone (group 2). Twelve hamsters were exposed to cigarette smoke and had no surgery (group 3). Eleven hamsters had no exposure to cigarette smoke and no surgery (group 4). All of the hamsters were sacrificed after 3 months. The gastric (wrapped) and splenic (unwrapped) lobes of the pancreas were reviewed grossly and histologically. In all 4 groups, there were no gross abnormalities in either lobe of the pancreas. Histopathologic evaluation of the gastric lobes from group 1 showed that 13 of 35 lobes (37%) had pancreatitis (11 chronic, 1 acute, and 1 both). In group 2, 12 of 32 (38%) gastric lobes had pancreatitis (10 chronic, 2 acute). The incidence of pancreatitis in groups 1 and 2 was significantly higher than in groups 3 (0/12; p < 0.04) and 4 (0/11; p < 0.03), respectively. A significantly lower incidence of pancreatitis was found in the splenic lobes of all 4 groups when compared to gastric lobes in groups 1 and 2. Three of the 67 cellophane-wrapped glands had ductal hyperplasia. The effects of cellophane wrapping of the pancreas, both in the wrapped and unwrapped areas, induced changes of pancreatitis and hyperplasia that may be preneoplastic. Cigarette smoking, alone or combined with cellophane wrapping, did not cause these changes. Longer exposure to cigarette smoke may be needed to cause premalignant changes in the hamster pancreas.

Predictive value of clinical features at initial presentation in pancreatic adenocarcinoma: a series of 308 cases

Pancreatic cancer is the fourth leading cause of cancer death in both men and women with a mortality incidence ratio of 0.99. In an effort to describe the role of clinical features at initial presentation, we conducted a retrospective observational study in patients with a biopsy-proven diagnosis of adenocarcinoma of the pancreas. Between 1986 and 2001, 308 patients (160 males, 148 females) were diagnosed with pancreatic adenocarcinoma. The mean age at diagnosis was 70.1 yr (range: 34-96 yr). The mean survival was 7.6 mo (range: 0-97 mo). Statistical analysis was performed using log-rank tests and analysis of variance. As expected, age at diagnosis was a significant factor affecting survival, with older patients doing relatively poorly (p < 0.05). Patients with a good performance status performed significantly better than those with a poor performance status (p < 0.01). In addition, the presence of the tumor in the head of the pancreas was a predictor for improved survival (p < 0.01). Although smoking increased the chances of detection at an earlier age, neither diabetes mellitus nor a positive smoking history had a statistically significant effect on the survival. Pancreatic adenocarcinoma is a disease of the elderly associated with a poorer outcome. Knowledge of possible clinical predictors of survival may lead to better patient counseling regarding prognosis.

Expression profiling of microdissected pancreatic adenocarcinomas

Pancreatic ductal adenocarcinoma is characterized by a paucity of neoplastic cells embedded in a densely desmoplastic stroma. Therefore, laser capture microdissection was performed to obtain homogeneous populations of normal and neoplastic ductal cells. These were subjected to a comparative study of gene expression utilizing human cDNA arrays. A variety of dysregulated genes were identified, comprising cell cycle and growth regulators, invasion regulators, signalling and developmental molecules. In addition to genes already found to be overexpressed in pancreatic cancer, such as TIMP1, MMP7, CD59, rhoC and NDKA, we present evidence to implicate genes which have not previously been reported in this tumour type. These include the overexpressed genes ABL2, Notch4 and SOD1, as well as XRCC1, a DNA repair gene whose transcript was found downregulated. Quantitative real-time RT-PCR (QRT-PCR) was employed to confirm differential expression of ABL2, Notch4 and SOD1 and immunohistochemical analysis was used to verify decreased protein expression of XRCC1 using a custom-built pancreatic tissue array. Combining microarray-derived gene expression profiles of pure pancreatic cell populations, QRT-PCR and pancreas-specific tissue arrays therefore proved to be highly informative in elucidating the molecular pathology of this highly malignant tumour type.

Pancreatitis as a risk for pancreatic cancer

Chronic pancreatitis clearly predisposes to pancreatic cancer, with early onset-long duration chronic pancreatitis from cystic fibrosis, TP, and HP conferring the highest risk. Chronic pancreatitis is not a critical step, however, but rather one of several conditions that accelerate the accumulation of critical genetic mutations and chromosomal losses necessary for carcinogenesis. Indeed, other germline mutations, environmental factors such as tobacco smoking and alcohol consumption, or dietary factors may also accelerate the pathway to carcinogenesis, and may be synergistic with the conditions created by chronic pancreatitis. Because patients with chronic pancreatitis are at high risk of pancreatic cancer, the physician is faced with decisions on how to manage this risk. Discontinuing smoking and alcohol consumption, and perhaps dietary modification are obvious recommendations for risk reduction. If, however, the patient is older and already in a very high-risk category (e.g., long-standing HP), then screening for cancers must be considered. Inclusion in multicenter trials is recommended, and information on ongoing studies can be obtained through the office of Dr. Whitcomb, or as posted on www.pancreas.org.

Sociodemographic diversity and behavioral medicine

The broad array of economic and cultural diversity in the U.S. population correlates with and impacts on the study of behavioral aspects of health. The purpose of this article was to provide a selective overview of behavioral medicine research on sociodemographically diverse populations, with a focus on ethnicity, gender, and socioeconomic status. Suggestions are provided with regard to methodological refinement of research and insights into possible future directions in behavioral medicine research on ethnically and economically diverse populations.

Surgery and cancer of the pancreas: will common sense become common practice?

Pancreatic cancer is a systemic disease for most patients. Operations with the intent to cure may be done safely (mortality, < 3%) with shorter hospital stays. Surgery has been minimally effective as a long-term cure. Endoscopic palliation of jaundice is becoming standard practice. Common sense dictates a defined and clear role for surgery (i.e., strict patient selection criteria). Surgery is of great value for small, localized lesions; of clear value as palliative therapy when nonoperative measures fail; and perhaps best applied after neoadjuvant chemoradiotherapy. Surgery is just part of the armamentarium available to treat pancreatic cancer. Novel systemic therapies, including chemotherapy, immunotherapy, and so-called targeted therapies, are becoming increasingly valuable in the management of this systemic disease and are discussed in detail in other articles in this issue.

Ethnic disparity of pancreatic cancer in New Zealand

BACKGROUND

The etiology of pancreatic cancer remains elusive. Identification of high-risk groups may enable targeted study to identify new markers and risk factors.

AIM

To review the epidemiology of pancreatic cancer in New Zealand and identify any differences between ethnic groups.

METHODS

All cases notified with pancreatic cancer between 1988 and 1997 were identified from the New Zealand Cancer Registry. Age-specific and age-standardized incidence rates (ASR) of pancreatic cancer were calculated for the total sample and the ethnic subgroups (Maori, Pacific, and Other, which was predominantly European). Data on the site, morphology, stage of tumors, and survival times were also reviewed.

RESULTS

There were 3004 cases over the 10-yr period. Ethnic ASR comparisons demonstrated higher rates in Maori (7.3/100,000) compared with Pacific (6.4/100,000) and the Other (5.6/100,000) ethnic group. Males had higher incidence rates than females in Pacific and Other, but not in Maori because of the unusually high rate among Maori women (7.2/100,000). The most commonly identified site, morphological type, and stage at presentation were the head of the pancreas (80.9% of site-specified cases), adenocarcinoma (44.3% of histologically confirmed cases), and diffuse +/- metastases (69.2% of staged cases), respectively. The median survival time was 92 d, and this did not differ significantly for the Maori and Other ethnic groups.

CONCLUSION

The Maori have higher rates of pancreatic cancer than other ethnic groups in New Zealand, and do not show the expected male predominance. Maori women currently have one of the highest reported female rates in the world, and are a population that should be further investigated for disease markers and modifiable risk factors.

Comorbidity and survival of elderly head and neck carcinoma patients

BACKGROUND

Alcohol and tobacco, the primary etiologic agents for head and neck carcinoma (HNCA), cause other chronic diseases and may contribute to the high prevalence of comorbid conditions and generally poor survival of persons with HNCA.

METHODS

The authors explored the prognostic role of comorbidity in persons with HNCA using Health Care Finance Administration Medicare (HCFA) files linked with the appropriate files of the Surveillance, Epidemiology, and End Results (SEER) Program. The Charlson comorbidity index was applied to in-patient data from the HCFA files. The SEER data were used to ascertain survival and identify persons with HNCA diagnosed from 1985 to 1993 (n = 9386).

RESULTS

In a proportional hazards regression model adjusted for age and historic stage at diagnosis, race, gender, marital status, socioeconomic status, histologic grade, anatomic site, treatment, and pre-1991 diagnosis, Charlson index scores of 0, 1, and 2+ had estimated relative hazards (RHs) with 95 confidence intervals (CIs) of 1.00, 1.33 (95% CI, 1.21-1.47), and 1.83 (95% CI, 1.64-2.05), respectively (P value for trend < 0.0001). The adjusted RH for a Charlson index score of 1 or more compared with 0, using stratified models, was found to be greater in whites (RH, 1.55; 95% CI, 1.43-1.67) than blacks (RH, 1.24; 95% CI, 0.96-1.60), local (RH, 1.72; 95% CI, 1.50-1.96) versus distant stage (RH, 1.25; 95% CI, 1.00-1.56), and age 65-74 years (RH, 1.53; 95% CI, 1.38-1.69) versus age 85+ years (RH, 1.42; 95% CI, 1.09-1.84).

CONCLUSIONS

This study establishes comorbidity as a predictor of survival in an elderly HNCA population and lends support to the inclusion of comorbidity assessment in prognostic staging of patients with HNCA diagnosed after 65 years of age.

Molecular biology of pancreatic cancer: potential clinical implications

The development of cancer involves the accumulation of genetic changes. Over the past decade there has a been spectacular advance in the knowledge of the genetic basis of cancer, mainly as a result of the rapid progression of molecular technology. Pancreatic cancer is one of the most lethal cancers. Conventional therapeutic approaches have not had much impact on the course of this aggressive neoplasm. Knowledge of the molecular biology of pancreatic cancer has grown rapidly. Genetic alterations in pancreatic cancer include oncogene mutations (most commonly K-ras mutations), and tumour suppressor gene alterations (mainly p53, p16, DCC, etc.). These advances have potential implications for the management of this deadly disease. Identification of a hereditary genetic predisposition to pancreatic cancer has led to the formation of pancreatic cancer registries around the world, with voluntary screening of patients and siblings for the hereditary genetic defect. Asymptomatic population screening remains unrealistic, but the recognition of subpopulations at increased risk from pancreatic cancer, along with novel and sensitive detection techniques, means that targeted population screening is a step closer. Intensive research is performed in specialist laboratories to improve the diagnostic approach in patients with pancreatic cancer. The use of such molecular diagnostic methods is likely to expand. Molecular biology may also have a great impact on the treatment of pancreatic cancer, and many therapeutic approaches are being evaluated in clinical trials, including gene replacement therapy, genetic prodrug activation therapy, antisense immunology and peptide technology. The 'molecular age' has the promise of delivering still better results. This review summarises recent data relating to the molecular biology of pancreatic cancer, with emphasis on features that may be of clinical significance for diagnosis and/or therapy.

Insulin secretion as a determinant of pancreatic cancer risk

New epidemiology confirms that glucose intolerance is a risk factor for pancreatic cancer, and that this association cannot be accounted for by an adverse impact of early pancreatic cancer on beta cell function. Previous reports indicate that risk for pancreatic cancer is increased in adult-onset diabetics. Since streptozotocin diabetes inhibits carcinogen-mediated induction of pancreatic cancer in hamsters, the most reasonable interpretation of these findings is that insulin (or some other beta cell product) acts as a promoter for pancreatic carcinogenesis. This view is consistent with a report that human pancreatic adenocarcinomas express insulin receptors that can stimulate mitosis; an additional possibility is that high insulin levels indirectly promote pancreatic carcinogenesis by boosting effective IGF-I activity via hepatic actions. In international ecologic epidemiology, pancreatic cancer rates correlate tightly with dietary intake of animal products; this may reflect the fact that vegan diets are associated with low diurnal insulin secretion. There is also suggestive evidence that macrobiotic vegan diets, which are low in glycemic index, may increase mean survival time in pancreatic cancer. However, other types of diets associated with decreased postprandial insulin response, such as high-protein diets or 'Mediterranean' diets high in oleic acid, may also have the potential for pancreatic cancer prevention. The huge increases of age-adjusted pancreatic cancer mortality in Japan and among African-Americans during the last century imply that pancreatic cancer is substantially preventable; a low-insulin-response diet coupled with exercise training, weight control, and smoking avoidance, commendable for a great many other reasons, may slash pancreatic cancer mortality dramatically.

Pancreatic cancer: the bigger picture

Despite accurate diagnosis, better radiologic techniques, and safer surgery, long-term survival after surgical therapy for pancreatic cancer is disappointing. Median survival following pancreaticoduodenal resection is 12 to 15 months independent of surgical expertise, hospital size, or technical factors. Subsets of favorable tumors and longer survival times after surgery have been defined and include: small tumor size and low-grade lesions, tumor-free margins, and absence of nodal, venous, or perineural invasion; however, long-term survivors of pancreatic cancer may have none of these favorable features, and their tumors commonly manifest the most adverse tumor prognostic features. The converse that small-sized, histologically favorable tumors result in long-term survivors, also is not true. Five-year survival rates average 5% or less after all resections. In a large series in which 118 pancreatic resections were performed in 684 evaluated patients over a 6-year period, there were 12 5-year survivors, 5 of whom died in the sixth year. A report of 10-year survivors after surgery numbered 13 patients. The best actual 5-year survival rate was reported by Trede et al. Of the 37, 5-year survivors from a cohort of 118 patients, more than half died of cancer. This far exceeds any other actual survival rate and may be explained by a smaller tumor size. Farnell et al reported a 5-year survival rate difference (i.e., actuarial survival) in a subset of 174 resected patients with adenocarcinoma without perineural or duodenal invasion and with negative nodes (23% versus 6.8%), respectively. An impressive, large series of 616 patients with resected adenocarcinoma of the pancreas who underwent PDR (85%), distal pancreatectomy (9%), and total pancreatectomy (6%), has been reported. The mortality rate was 2.1%, and postoperative complications occurred in 30%. The five-year survival rate was 15%. The author's best result was observed among 20 initially "unresectable" patients who were treated with chemoradiation therapy, followed by tumor extirpation. Among the 18 surgical survivors there are seven five-year survivors, three of whom are in their tenth year of survival. They are discussed in the article by Cooperman et al ("Long-term Follow-up...") elsewhere in this issue.

Diet and cancer

The large differences in cancer rates among countries, striking changes in these rates among migrating populations, and rapid changes over time within countries indicate that some aspect of lifestyle or environment is largely responsible for the common cancers in Western countries. Dietary fat has been hypothesized to be the key factor because national consumption is correlated with the international differences. However, detailed analyses in large prospective studies have not supported an important role of dietary fat. Instead, positive energy balance, reflected in early age at menarche and weight gain as an adult, is an important determinant of breast and colon cancers, consistent with numerous studies in animals. As a contributor to positive energy balance, and possibly by other mechanisms, physical inactivity has also been shown to be a risk factor for these diseases and in part accounts for the international differences. Although the percentage of calories from fat in the diet does not appear related to risk of colon cancer, greater risks have been seen with higher consumption of red meat, suggesting that factors other than fat per se are important. In many case-control studies, a high consumption of fruits and vegetables has been associated with reduced risks of numerous cancers, but recent prospective studies suggest these associations may have been overstated. Among the factors in fruits and vegetables that have been examined in relation to cancer risk, present data most strongly support a benefit of higher folic acid consumption in reducing risks of colon and breast cancers. These findings have been bolstered by an association between incidence of colon cancer and a polymorphism in the gene for methylenetetrahydrofolate reductase, an enzyme involved in folic acid metabolism. The benefits of folic acid appear strongest among persons who regularly consume alcohol, which itself is associated with risk of these cancers. Numerous other aspects of diet are hypothesized to influence the risks of cancers in Western countries, but for the moment the evidence is unclear.

A novel immunocytolytic factor secreted by pancreatic adenocarcinoma

BACKGROUND

We have observed a putative immunocytolytic factor secreted by several pancreatic adenocarcinoma cell lines that mediates a potent cytolytic effect on lymphocytes. We sought to investigate its mechanism of action and determine if it is Fas ligand (FasL)-mediated.

MATERIALS AND METHODS

Coincubation assays with murine splenocytes and supernatants from various species of pancreatic adenocarcinoma cell lines were performed. The mechanism of lymphocytic cell death was evaluated by the TUNEL assay. Pancreatic adenocarcinoma supernatant was coincubated with Fas-sensitive Jurkat cells and Western blotting for FasL was performed.

RESULTS

A marked reduction in the viability (%/control) of target splenocytes was observed after incubation with the conditioned media from hamster PAN-1 (14.7%), PC 1.0 (21.7%), Taka-1 p70 (12.4%), Taka-1 p79 (7.6%), murine PANCO2 (16.1%), and human Capan-1 (14.0%) pancreatic adenocarcinoma cell lines. FACS analysis demonstrated significant lymphoid apoptosis at 16 h. The cytolytic effect appeared to be specific for lymphocytes and was not observed with the conditioned media of other tumor cells or normal pancreatic ductal cells. Pancreatic adenocarcinoma supernatant had no killing effect on Jurkat cells compared with control supernatant of TC-248 cells (87% vs 15%) and immunoblotting did not demonstrate soluble FasL.

CONCLUSIONS

These findings demonstrate that pancreatic adenocarcinoma cells secrete a potent cytolytic factor that induces apoptosis of lymphocytes and is not FasL-mediated.

K-Ras mutations and benign pancreatic disease

This review addresses the history of the ras oncogene, the techniques used to detect molecular alterations in the ras oncogene, and the application of polymerase chain reaction (PCR)-based methods to determine point mutations in clinical samples of patients with pancreatic diseases, namely pancreatic carcinoma and chronic pancreatitis. The frequency of ras mutations in pancreatic carcinoma is high, ranging from 70 to almost 100%. The frequence of ras mutations in chronic pancreatitis, either in pancreatic tissue or pancreatic secretions, vary between 0 and 100%. This wide range in part may be owing to differences in sampling, DNA extraction, or PCR method. The meaning of a k-ras mutation is under debate. Taking into account the positivity of ductal hyperplasias in normal pancreas and ras mutations in normal appearing duct cells, this molecular finding may not mean anything. In contrast, ras mutations are associated with smoking, one acknowledged risk factor for pancreatic carcinoma. The need for large prospective cohort studies is emphasized.

Association between coffee drinking and K-ras mutations in exocrine pancreatic cancer. PANKRAS II Study Group

STUDY OBJECTIVE

To analyse the relation between coffee consumption and mutations in the K-ras gene in exocrine pancreatic cancer.

DESIGN

Case-case study. Consumption of coffee among cases with the activating mutation in the K-ras gene was compared with that of cases without the mutation.

SETTING AND PATIENTS

All cases of pancreatic cancer newly diagnosed at five hospitals in Spain during three years were included in the PANKRAS II Study (n = 185, of whom 121 whose tissue was available for molecular analysis are the object of the present report). Over 88% were personally interviewed in hospital. DNA was amplified from paraffin wax embedded tissues, and mutations in codon 12 of K-ras were detected by the artificial RFLP technique.

MAIN RESULTS

Mutations were found in tumours from 94 of 121 patients (77.7%). Mutations were more common among regular coffee drinkers than among non-regular coffee drinkers (82.0% v 55.6%, p = 0.018, n = 107). The odds ratio adjusted by age, sex, smoking and alcohol drinking was 5.41 (95% CI 1.64, 17.78). The weekly intake of coffee was significantly higher among patients with a mutated tumour (mean of 14.5 cups/week v 8.8 among patients with a wild type tumour, p < 0.05). With respect to non-regular coffee drinkers, the odds ratio of a mutated tumour adjusted by age, sex, smoking and alcohol drinking was 3.26 for drinkers of 2-7 cups/week, 5.77 for drinkers of 8-14 cups/week and 9.99 for drinkers of > or = 15 cups/week (p < 0.01, test for trend).

CONCLUSIONS

Pancreatic cancer cases without activating mutations in the K-ras gene had drank significantly less coffee than cases with a mutation, with a significant dose response relation: the less they drank, the less likely their tumours were to harbour a mutation. In exocrine pancreatic cancer the K-ras gene may be activated less often among non-regular coffee drinkers than among regular drinkers. Caffeine, other coffee compounds or other factors with which coffee drinking is associated may modulate K-ras activation.

Hereditary pancreatitis and pancreatic carcinoma

Few risk factors for pancreatic cancer have emerged except for chronic pancreatitis. Recently, hereditary pancreatitis was estimated to carry a standardized incidence ratio of 53, a risk about 25 times higher than smoking. A review of the ongoing hereditary pancreatitis study of the Midwest Multicenter Pancreatic Study Group suggests that the risk of pancreatic cancer is related to long-standing pancreatitis rather than to the cationic trypsinogen mutations. No recommendations can be made on screening patients with hereditary pancreatitis for pancreatic cancer at this time. However, prospective data, serum, and pancreatic juice should be collected and banked on consenting patients at risk as part of prospective, multicenter trials so that evidence-based recommendations for hereditary pancreatitis and other types of chronic pancreatitis can be made in the future.

The increased incidence of cancer of the pancreas: is there a missing dietary factor? Can it be reversed?

There has been a disturbing increase in the incidence of pancreas cancer, especially in Western countries, during the present century. The only well-established aetiological factor of well-documented significance is the greater incidence of this cancer in tobacco smokers of all communities. Otherwise the reason for the increased incidence is not known but the pattern of increase has some similarities to the increased incidence of breast cancer in women and prostate cancer in men in Western communities. There is now well-documented evidence that the increase in breast and prostate cancers is at least partly related to diet. Typical modern Western diets have a low content of the naturally occurring plant hormones, the phyto-oestrogens, that are still plentiful in traditional diets of Asians and other communities with a low incidence of both breast and prostate cancer. This paper presents evidence to support the hypothesis that the increased incidence of pancreas cancer in Western communities may also be related to the relatively low dietary content and protective qualities of the naturally occurring plant hormones and related compounds. This paper presents evidence to support that hypothesis.

Pancreatic cancer: can we screen? How should we stage?

Pancreatic cancer remains a deadly disease, with few patients surviving 5 years following diagnosis. Surgical resection remains the only treatment associated with the potential for cure; however, most patients have locally advanced or metastatic disease at presentation and thus are not surgical candidates. Advances in imaging technologies, biochemistry, and molecular genetics have raised hopes of improving the outcome for patients with pancreatic cancer through earlier and more accurate diagnosis. As our knowledge of the genetics of pancreatic cancer has increased, the possibility of screening to identify patients at risk to develop the disease also holds promise. This review focuses on the utility of current modalities to screen for pancreatic cancer as well as the most accurate and expedient methods to stage the disease.

Evaluation of positron emission tomography with 2-[18F]fluoro-2-deoxy-D-glucose for the differentiation of chronic pancreatitis and pancreatic cancer

BACKGROUND

The clinical presentation of patients with pancreatic cancer may resemble the clinical picture of chronic pancreatitis. A definitive preoperative diagnosis is not always obtained in patients with a history of chronic pancreatitis despite the use of modern imaging techniques. Operative strategy therefore remains unclear before operation in these patients.

METHODS

Positron emission tomography (PET) with 2-[18F]fluoro-2-deoxy-D-glucose (FDG) was introduced recently into clinical oncology because of its ability to demonstrate metabolic changes associated with various disease processes. The impact of FDG-PET on the differentiation of chronic pancreatitis and pancreatic cancer was investigated. FDG-PET was performed in 48 patients with chronic pancreatitis (n = 12), acute pancreatitis (n = 3) and pancreatic cancer (n = 27), and in controls (n = 6). Histological examination was undertaken in all cases except controls. The FDG-PET results were obtained without knowledge of results of other imaging procedures. The results were then compared with those of computed tomography, ultrasonography, endoscopic retrograde cholangiopancreaticography, operative findings and histology. PET images were analysed semiquantitatively by calculating a standard uptake value (SUV) 90-120 min after application of the tracer.

RESULTS

Cut-off values were validated as follows: SUV greater than 4.0 for pancreatic cancer, SUV of 3.0-4.0 for chronic pancreatitis, and SUV of less than 3.0 for controls. Sensitivity and specificity of PET imaging were 0.96 and 1.0 for pancreatic cancer, and 1.0 and 0.97 for chronic pancreatitis. In five cases only FDG-PET led to the correct preoperative diagnosis.

CONCLUSION

The results give further evidence that FDG-PET is an important non-invasive method for the differentiation of chronic pancreatitis and pancreatic cancer. Delayed image acquisition in the glycolysis plateau phase permits improved diagnostic performance. This imaging technique is extremely helpful before operation in patients with an otherwise unclear pancreatic mass, despite its costs.

[Does neoadjuvant radiochemotherapy augment the resectability of pancreatic cancers?]

PURPOSE OF THE STUDY

Pre-operative radiochemotherapy is the most recent therapeutic option in the pre-operative downstaging of pancreatic cancer and in decreasing the rate of positive resection margins. The purpose of the study was to evaluate tolerance and efficacy of pre-operative radiochemotherapy in unresectable pancreatic cancers.

MATERIAL AND METHODS

This study included seven cases of pancreatic cancer considered unresectable. The patients received preoperatively 50 grays within a 5-week period associated with 5 FU and Platin during the 1st and 5th weeks.

RESULTS

After radiochemotherapy, tomodensitometric evaluation showed a minor response in two cases. A pancreatico-duodenectomy could be performed in these two patients without any increase of pre- or post-operative morbidity or mortality.

CONCLUSIONS

The results of the study suggest that preoperative radiochemotherapy may increase pancreatic cancer resectability. This hypothesis should be confirmed by a prospective randomised trial.

Inducibility of cytochromes P-4502E1 and P-4501A1 in the rat pancreas

Cytochrome P-450 (CYP) isoenzymes have been incriminated in the toxicity and carcinogenicity of various xenobiotics in different tissues, but prior measurements of their activity in pancreatic microsomes have been disappointing. We now applied new isolation methods and a highly sensitive procedure to assay for the metabolism of p-nitrophenol and 7-ethoxyresorufin, specific substrates for CYP2E1 (2E1) and CYP1A1 (1A1), respectively. 2E1 and 1A1 content was estimated with high-resolution chemiluminescent Western blots using recombinant 2E1 and 1A1 as standards. We found that p-nitrophenol hydroxylase activity was 5.07 +/- 0.66 and 1.50 +/- 0.26 pmol/ min/mg of protein in pancreatic microsomes of ethanol-fed and control rats, respectively. Chronic ethanol treatment increased 2E1 content in pancreatic microsomes 3.6-fold. Activity and content of 2E1 were also assessed in hepatic microsomes: specific activity (expressed per 2E1 content) was similar in pancreatic and hepatic microsomes. There was also an inductive effect of 3-methylcholanthrene (MC) on 1A1 in pancreatic microsomes. Pancreatic microsomal 7-ethoxyresorufin-O-dealkylation activity in MC-treated rats was 19.6 +/- 1.7 pmol/min/mg of protein, 61-fold higher than in controls. MC treatment increased the 1A1 content in pancreatic microsomes 42-fold. These results demonstrate that, in pancreatic microsomes, ethanol and MC exert striking inductive effects on 2E1 and 1A1 activities, which could play a role in the pathogenesis of pancreatitis and/or pancreatic cancer.

Statewide regionalization of pancreaticoduodenectomy and its effect on in-hospital mortality

OBJECTIVE

This study examined a statewide trend in Maryland toward regionalization of pancreaticoduodenectomy over a 12-year period and its effect on statewide in-hospital mortality rates for this procedure.

SUMMARY BACKGROUND DATA

Previous studies have demonstrated that the best outcomes are achieved in centers performing large numbers of pancreaticoduodenectomies, which suggests that regionalization could lower the overall in-hospital mortality rate for this procedure.

METHODS

Maryland state hospital discharge data were used to select records of patients undergoing a pancreaticoduodenectomy between 1984 and 1995. Hospitals were classified into high-volume and low-volume provider groups. Trends in surgical volume and mortality rates were examined by provider group and for the entire state. Regression analyses were used to examine whether hospital share of pancreaticoduodenectomies was a significant predictor of the in-hospital mortality rate, adjusting for study year and patient characteristics. The portion of the decline in the statewide in-hospital mortality rate for this procedure attributable to the high-volume provider's increasing share was determined.

RESULTS

A total of 795 pancreaticoduodenectomies were performed in Maryland at 43 hospitals from 1984 to 1995 (Maryland residents only). During this period, one institution increased its yearly share of pancreaticoduodenectomies from 20.7% to 58.5%, and the statewide in-hospital mortality rate for the procedure decreased from 17.2% to 4.9%. After adjustment for patient characteristics and study year, hospital share remained a significant predictor of mortality. An estimated 61% of the decline in the statewide in-hospital mortality rate for the procedure was attributable to the increase in share of discharges at the high-volume provider.

CONCLUSIONS

A trend toward regionalization of pancreaticoduodenectomy over a 12-year period in Maryland was associated with a significant decrease in the statewide in-hospital mortality rate for this procedure, demonstrating the effectiveness of regionalization for high-risk surgery.

Pancreatic adenocarcinoma: epidemiology and genetics

Pancreatic adenocarcinoma is an important cause of death from cancer throughout the developed world. There are few established environmental risk factors, but a previous history of pancreatitis and exposure to tobacco and salted food appear to be the most important. A family history of pancreatic adenocarcinoma is not common in patients with this disease, but recent research has shown that pancreatic adenocarcinoma can be a feature of cancer susceptibility syndromes associated with germline mutations in p16, BRCA1, BRCA2, and APC. This highlights the need for a full family history in apparently sporadic cases. Somatic mutations in p16, BRCA2, and APC have also been reported in pancreatic cancer; however, K-RAS mutations appear to be the commonest oncogenic alteration. Recent advances in our understanding of the basis of hereditary cancer syndromes may be applicable to the diagnosis, treatment, and possibly prevention of pancreatic adenocarcinoma in the future.