Global Incidence of Pancreatic Adenocarcinoma

Introduction

North America and Western Europe has for a long time now recorded the highest number of patients being diagnosed with pancreatic adenocarcinoma with the rate of 7.4 per 100000 people and 6.8 per 100000 people in the population respectively. The lowest rates have been recorded in the continents of Asia and Africa, the former having a rate of 3.2 per 100000 people and the latter having 2.0 per 100000 people in the population (Simoes et al.,2017). It is important to note that men have a higher probability of developing pancreatic adenocarcinoma compared to women with a rate of 4.9 against 3.6 per 100000 people respectively (Ryan et al.,2014). It is also important to note that risk of developing adenocarcinoma of the pancreas increases with old age with those between 55-59 65-69 years having the rate of 10.4 per 100000 people, those between years 65-69 having the rate of 24.0 per 100000 people and those above 75 years having a staggering rate of 55.7 per 100000 people. It frequently arises due to a number of risk factors that may either be environmental such as smoking, lifestyle factors such as chronic alcohol use and diet rich in animal fat, health factors such as chronic pancreatitis and chronic diabetes and genetic factors that may arise after studying one’s family history with chances of it arising 18-fold when it is an immediate relative. Unfortunately, its prognosis is worse as collected data show long term survival is very rare. Although surgical removal is a definite treatment option by an oncologist statistics show that only 10-20% of these patients survive for more than 5 years with 50% of them having recurring cancer and those having been diagnosed in the late stages having an average survival time of 6 months and about 20% of them surviving past 1 year and only 1% for more than 5 years (Ryan et al.,2014). Some of the other treatments apart from resection include radiotherapy, chemotherapy, palliative care, physiotherapy and dietary guide. What makes pancreatic adenocarcinoma quite dangerous is that it has no symptoms in its early stages hence the patient only finds out about their condition in the late stages where most of the time it is incurable. Accompanying symptoms in the late stages are non-specific and vary with about 90% of the patients but the most common including long standing pain from the upper abdomen through the back, weight loss, lack of appetite, nausea, vomiting, fatigue, dark urine and jaundice (Simoes et al.,2017). Although there are many options and technological advancements that have simplified the process of cancer determination, specificity and accuracy and in particular Pancreatic Adenocarcinoma, there is still remains a need for knowing which the best methods are for the function of its detection. It is rapidly gaining the attention of many medical practitioners around the world as the number of patients being diagnosed having it are increasing with time and unfortunately, they end up being long overdue for treatment (Simoes et al.,2017). A structured literature review is needed to help determine the best method between ultrasound and a CT scan in the specification and identification of Pancreatic Adenocarcinoma in patients. Information and data collected and analyzed will aid physicians in simplifying the cancer identification process.

BACKGROUND

The diagnosis of this cancer is very crucial as it determines the next course of action for the patient especially if it is in the early stages where resection is still an option. Pancreatic adenocarcinoma has been found to be quite dangerous as it has no specific symptoms in its early stages as a result, the patient only finds out about their condition in the late stages where most of the time it is incurable or becomes hard to completely cure. There are however, several techniques used to detect this cancer (Freeny et al.,2010). Some of the techniques which can be used for this are techniques such as; ultrasonography (US), spiral computed tomography (CT) and magnetic resonance imaging (MRI). Others include physical examination, blood tests where biological markers of inflammation are noted or pancreatic juice in blood is detected and tumor markers such as CA 19-9 and CEA. TNM Classification of Malignant Tumors (TNM System) (AJCC, 2016), by Pierre Denoix is used to determine the stage of the cancer. Determining the stage is done with the help of chest x-rays, magnetic resonance imaging, ultrasound scan and diagnostic laparoscopy. The TNM classification of malignant tissues is very crucial in pancreatic cancer treatment. Small, low grade cancer with no metastasis and has not spread to regional lymph nodes can use resection as treatment compared to high grade cancer(Tummala, Junaidi, & Agarwal, 2011) . CT is a computerized axial tomography scan that generates 3D volume from a series of 2D radiographic images taken around an axis of rotation. It is considered to be of a much greater accuracy than the ultrasound due to its precise diagnostic technique. The CT scan works by using computer processed combinations of x-ray measurements of the abdominal region, specifically the pancreatic region, which are taken from different angles to obtain the tomographic of the specific area. Moderate to high radiation diagnostic technique is used depending on the body region. Computed tomography is always the first line of action when a person is suspected to have pancreatic cancer (Treadwell et al.,2016).

It is more effective in its function because it eliminates superimposition of images of structures outside the region of the pancreas making it easier to see a mass of inflamed cells. It has an inherent high contrast resolution different between tissues in the body that differ in physical density by less than 1% making the tissues very distinguishable. Diffusion-weighted magnetic resonance imaging(DWI) as well as multidetector-row CT (MDCT) have also been discovered to be efficient for patients with higher risks in distinguishing pancreatic cancer with main pancreatic duct dilation with accuracy rates of 84% and 86% respectively (Tummala et al., 2011). Furthermore, computerized tomography provides multiplanar reformatted imaging as data from a single CT scan which has multiple contiguous or one helical scan can be viewed in an axial, coronal or sagittal plane. Computed tomography (Grenacher & Klaub 2010) is also used because of its high speed considering it is computer processed. CT has broad availability, can be carried out faster, saves on costs more therefore is effective and has no requirement of the patient being anaesthetized or sedated. It also focuses on the area needed hence only a thin section is obtained. Further it optimally enhances the images to be of a higher definition standard hence easily interpreted and clearer (Tummala et al., 2011). This is especially attributed to its spatial resolution which is high as more pixels are used to construct a digital image. Moreover, it is important in the accurate staging of the pancreatic adenocarcinoma to determine the right treatment. The unavoidable disadvantages of CT scan are that when it is offered as a full body scan, it can easily lead to cancer because it damages body cells together with DNA molecules which may lead to cell mutation (Freeny et al.,2010). Most of the time when the scan is performed on a specific part of the body, volume of the scanner, patient build, desired resolution and image quality is put into consideration. Another disadvantage is the intravenous contrast injected into the patient during the CT scan is not pleasant and cause side effects to the patient. Ultrasound on the other hand is used with patients who are symptomatic and many not feel comfortable with the CT scan (Gincul et al.,2014). The ultrasonography method is also quite useful in determining if the venous system has been infected. Although the ultrasound is not useful during staging of the tumor it is quite useful with small tumors using endoscopic ultrasound (EUS) when done by experienced clinicians (Arcidiacono PG, 2017). However, transabdominal ultrasound has relatively very poor sensitivity and the results are suboptimal in patients mostly due to bad acoustic window as a result of gas from the bowel. Its sensitivity is 95%. Furthermore, endoscopic ultrasound cannot differentiate benign from malignant using ultrasound. This proves that the computed tomography method to be more efficient during diagnosis of pancreatic adenocarcinoma (Tummala et al., 2011).However, for a clear distinction to be made between the two methods of detecting pancreatic adenocarcinoma and the best one determined, a structured literature review is needed to help in the whole process of determining the best method between ultrasound US and a computed tomography CT scan in the specification and identification of Pancreatic Adenocarcinoma in patients. Information and data collected and analyzed will aid physicians in simplifying the cancer identification process.

RESEARCH AIMS AND OBJECTIVES

When putting together this write up, the main aim of this is to critically evaluate the effectiveness and accuracy of the computed tomography scan (CT) while considering the cross-sectional studies, cohorts and medical journals that have looked into its effectiveness because it is always considered as the first case action during diagnosis. Its effectiveness is in comparison to the ultrasound US method of diagnosis which has been less reliable but is still being used during some diagnostic procedures. During this analysis, so as to obtain viable information while using the data collected and methodologies, a set of realistic objectives have to be established to guide the analysis (Boell and Cecez-Kecmanovic,2014).

Objectives

To establish the effect of both the CT scan and ultrasound to the health of the patients.

To access the availability of both diagnosis methods to the majority population of citizens.

To analyze the quality of the imaging of each of the diagnosis methods

The identify the possible improvements that can be made in both diagnosis methods

Research Question

How effective and accurate is computed tomography CT scan compared to Ultrasound US in the detection of Pancreatic Adenocarcinoma?

PERSPECTIVE AND METHODOLOGY

The PICO framework was used as it was the most efficient method in this evaluation for thorough covering of this research (Appendix 1). In the quest to archive all the set objectives and eventually archive the main aim of the write up, it is important to determine the perspectives to take and the methodologies that are best for this kind of evaluation. One has to decide on the best search strategy to use as this is important in order to have a structured literature review. As the PICO framework is also in use, relevant research questions should be formed and interventions found at the end of the study. After analyzing all the important facts, the best approach is selected for the research study either qualitative or quantitative methods and strategies are picked in order for the research questions to be answered best. A number of criteria were used to determine and decide on the best quantitative dataset to thoroughly evaluate the two techniques, computed tomography CT scan and ultrasound US. Quantitative review required the inclusion of case-controls, cross-sectional studies, non-experimental studies, cohorts and random control trials. An approach is to be decided that will later determine the research design and research quest (Boell and Cecez-Kecmanovic,2014). This particular review is best considered quantitative review. Quantitative research relies on a deductive type of approach for data collection and analysis and for theory testing because the theory gathered is being tested on the field. Deductive research is particularly used in reviews dealing with clinical and healthcare related topics especially in accuracy in diagnosis. The best kind of data that would be used is primary data as it is from recent occurrences that may easily relate to the study. All this would later be backed up with secondary data from medical journals and databases with previous studies that may shed more light to the review. The different methodologies to be implemented were noted and those that facilitate the collection of primary data were given preference first especially since it is a quantitative type of review. Experiments were conducted on individuals who required to go through diagnosis after they gave their consent and agreed to contribute to the evaluation. Individuals both male and female included were diagnosed differently with either of them using computed tomography or ultrasound and were later interviewed on their experience during the diagnosis, the ease, the challenges and how they felt about the efficiency of each of these methods (Wang et al.,2014). Their results after critical analysis by the clinician was shown and a more efficient and reliable imaging was obtained from the CT scan. The patient feedback was different among patients who were already ailing and were showing symptoms as they felt the ultrasound was just good though a little uncomfortable. Surveys were also thoroughly done in several medical facilities on which diagnosis method is most preferred by the clinicians. The feedback was more inclined to prove the theory being closer to reality as a large number of them who had access to both methods of diagnosis opted for the CT scan and only and handful preferring the ultrasound. Interviews with oncologists were an eye opener as most of them said using results from both types of diagnosis can never be wrong because sometimes these two diagnostic methods complement each other effectively. The Delphi method was not used often before but every opinion had to count in this review. A large crowd of people who consisted of both clinicians and patients were required to give their range of opinions on those particular subjects of evaluation in this particular review. Different people expressed different opinion and it almost crossed to be a heated argument among some of the people brought to give their opinions. It was quite hard to come into a consensus with everyone arguing on whether computed tomography is more efficient or ultrasound is.

Another method employed was observational trials where those diagnosed with pancreatic cancer being studied in large groups known as cohorts in the comfort of their homes and palliative care centers. The longitudinal approaches proved to be very challenging especially due to the poor prognosis that does not allow long term monitoring. However, a cohort group voluntarily gave a retrospective approach on their medical charts and experience over time. This method proved not to be as ideal as hoped for because some of them gave exaggerated explanations and some failed to remember how their diagnosis went through. Analytical observational studies such as case controls and cross sectional studies were conducted to determine the correlations of interventions and health outcomes. Nevertheless, this specific methodology is also quite unreliable due to factors that determine how far this methodology would go, such as the remaining patient population, and patient availability (Wang et al.,2014). However cross section studies still proved to be a bit more useful as they can give a strong external validity due to its broad information on the wider population and they also manage to give a detailed description of absolute risk, relative risk and odd ratio. From these methodologies, values were obtained for both computed tomography CT scan as well as ultrasound US after the merge of data from prior research done, series of tests and diagnosis outcomes. Secondary data also had to be included to be able to make a concrete review and make a summary that could reflect the current situation and that recorded in the past in addition to the primary data that was collected using the methodologies. Materials which are up to date are the most useful even during research because innovation, modification and transformation are constant occurrences that need to be embraced (Boell and Cecez-Kecmanovic,2014). It is always possible to upload verified research to these internet databases to help others working to improve other conditions and also help them get data to refer from when doing related research. Medical journals in databases from the internet such as MEDSCAPE and articles from authors such as Mary Ann Liebert that can be easily accessed anywhere were of much help during the whole research (Boell and Cecez-Kecmanovic,2014). From the appendix 2, the outline of the inclusion and exclusion criteria employed in this study is clearly outlined. The inclusion and exclusion criteria used in this study was chosen after a lot of research to help in finding the intervention for the research question or the aim of this study.

METHODS

LITERATURE SEARCH STRATEGY

From the primary data that is collected through the methodologies highlighted, new information with better interpretation is evaluated (Amrollahi et al.,2013). Further analysis of this same information can further enhance innovation as both computed tomography and the ultrasound will undergo enhancements to avoid further demerits that may have arose in the review. More books and publications would be made using the same information so that references can easily be made in the near future during further evaluation of more techniques that may be used for pancreatic adenocarcinoma including CT scan and ultrasound (Treadwell et al.,2016). The primary data obtained can even be further uploaded in the databases and servers of the internet to be accessible to any person interest all over the world. In the current evaluation a lot of material from primary data to secondary data to tertiary data and in the field, books, journals and internet has been essential for the review (Amrollahi et al.,2013). Electronic databases such as MEDSCAPE, PUBMED, TOXNET and POPLINE are widely used by many different people worldwide who need information from these journals and articles that were once collected as primary raw data and processed to refinement and ready for access by the broad population of the public. Materials that are up to date are the most useful even during research because innovation, modification and transformation are constant occurrences that need to be embraced. It is always possible to upload verified research to these internet databases to help others working to improve other conditions (Boell and Cecez-Kecmanovic,2014). The strategy usually applied to frame a search and narrow down the results to the most relevant studies is the use of keywords this fastens the speed of retrieving information on computed tomography scan or ultrasound. Keywords may also end up bringing a wide results of items than the intended hence, keywords of similar meaning are best used to narrow the search as much as possible to be able to locate the database information as quick as possible. Boolean operators are also quite useful to facilitate a quick search.

QUALITY ASSESSMENT

Quality assessment is very useful in ensuring that all the information provided in the evaluation provided above is up to date and there is no omission of information to favor either computed tomography scan or the ultrasound for one malicious reason or the other (Wang et al.,2014). The quality assessment is an essential part of the study as it helps in reducing any issues of biasness that may come up in the results. It is important to ensure the primary sources of study undergo quality assessment. This happens after the inclusion criteria has been used in the study. The quality assessments also help give a deeper interpretation and understanding of the results from the study. A suitable quality assessment tool is therefore, very crucial in analysis and interpretation of the data provided (Westwood et al. 2011). The one reliable tool is the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) and has been trusted for a number of years and has frequently been recommended by the Cochrane Collaboration together with the Agency of Healthcare Research and Quality and the United Kingdom National Institute for Health and Clinical Excellence (Whiting et al.,2011). The new version of this quality assessment tool has amazing tools such as index tests, reference standards and the skill to select patients. Through this, it ensures any data used in the research is not likely to be biased and it also monitors timing and flow and is considered very effective. Bias is considered minimal if questions are answered positively. The quality assessment results by (QUADAS-2) in two important graphs (Whiting et al.,2011). One graph showing the level of bias in in the evaluation study conducted and monitored by the quality assessment tool and the other a graph of the overview of the results obtained from the review study in percentages (Appendix 5). The quality assessment tool is mostly crucial to provide information to the public about the work produced. The information is mostly for the public health information systems about how data is used and the collection of data (Boell and Cecez-Kecmanovic,2014). This is also important to prevent the long type of information from reaching the public. After employing the QUADAS-2 to verify all the primary data used in the research study, the bias is ruled out and final results obtained are deemed credible and very unbiased. The whole approach ensures that biased data which may affect the results negatively are not use or included in the whole study. In short, it guarantees credibility.

DATA EXTRACTION TOOL

It is relevant to obtain relevant data from the study in order for it to be use effectively in the evaluation (Bettany & Saltikov 2012). From appendix 3, It is important to use effective methods as indicated in the appendix to help solve the study question and achieve the aim. Credible data should be obtained effectively from the primary studies and also secondary studies. From the aims and study question, it is clear that the study seeks to ascertain the best method of detecting pancreatic adenocarcinoma between computed tomography CT scan and Ultrasound US (Freeny et al.,2010). Computer based programs are also required during this process for effectiveness for example Excel spreadsheets for data processing, analysis and visualization. For the inclusion criteria data and reviews to be taken into consideration, the sensitivity enhanced as well as the specificity of the study, primary studies data may not be enough. This is when profound sensitivity, specificity and the accuracy of the research study is being tested. In determining the accuracy of computed tomography against ultrasound in the diagnosis of pancreatic adenocarcinoma specificity is crucial because it reflects on accuracy and data from primary data is not accurate enough until incorporated with other sets of data:

Probability of the prevalence of the pancreatic cancer in the population Probability of post –test probability being negative or positive Sensitivity and specificity of CT scan and ultrasound performed Values of positives and negative.

TIMETABLE

While pursuing Master’s Degree at Glasow Caledonai, during the third semester the review is researched, discussed and written. After approval by the supervisor research begins with search for data bases and primary studies. Once enough information is gathered there will be a lot of visits that are quite frequent to the supervisor for critical evaluation of the research and ensuring it is practical. The meetings with the supervisor will be at least twice a month where we would link up and an update of the development of the proposal would be discussed (Appendix 4)

BUDJET AND FUNDING

During the research a lot of expenses had been incurred not only in terms of monetary value but also time. Accessing most of the books and articles physically proved relatively easier because of the access to the university library which is relatively informative. Access to the online databases was also done through the university library. Most of the expenses were from the writing and publishing of this copy for research including printing, binding and making copies of this publication. The researcher bore all these expenses but some part of it was covered by the sponsorship provided by the university. There are also costs on the translation of this article to the different other languages because it was written in English during the publication.

DISSEMINATION OF RESULTS

This evaluation compilation will hopefully contribute to the medical field especially the radiology sector. This write up will also hopefully inspire further development and improvement in both computed tomography scan and also ultrasound especially after the comparisons were well highlighted. This evidence based publication will hopefully also be disseminated in health related conferences where clinicians and academicians can critically view it and include it in projects that would involve the field of radiology.

REFERENCES

American Joint Committee on Cancer (AJCC) Cancer Staging Manual (8th edition) 2016. ISBN 3319406175.

Amrollahi, A., Ghapanchi, A.H. and Talaei-Khoei, A., 2013. A systematic literature review on strategic information systems planning: Insights from the past decade. Verified OK.

Arcidiacono PG. Re-defining the role of EUS in pancreatic adenocarcinoma in 2017. Endoc Ultrasound. 2017 Dec. 6 ( Suppl 3): S57.

Bettany-Saltikov, J., 2012. How to do a systematic literature review in nursing: a step-by-step guide [online]

Boell, S.K. and Cecez-Kecmanovic, D., 2014. A hermeneutic approach for conducting literature reviews and literature searches. CAIS, 34, p.12.

Brierley, J.D.; Gospodarowicz, M.K.; Wittekind, Ch., eds. (2017). TNM classification of malignant tumors (8th edition). Chichester, West Sussex, UK: Wiley-Blackwell.

Coughlan, M., Ryan, F., 2008. Undertaking a literature review: a step-by-step approach. British Journal of Nursing.

Davies, K.J., Shultz, M., L.V., Gault, (2002) ‘Variations in medical subject headings (MeSH) mapping: from the natural language of patron terms to the controlled vocabulary of mapped lists’, Journal of the Medical Library Association, 90(2),pp. 173-180

Gincul, R., Palazzo, M., Pujol, B., Tubach, F., Palazzo, L., Lefort, C., Fumex, F., Lombard, A., Ribeiro, D., Fabre, M. and Hervieu, V., 2014. Contrast-harmonic endoscopic ultrasound for the diagnosis of pancreatic adenocarcinoma: a prospective multicenter trial. Endoscopy, 46(05), pp.373-379.

Hunt, J. 2013, "How to do a systematic literature review in nursing", Nursing Children and Young People, [online], vol. 25, no. 3, pp. 12.

Lydiatt, William M.: Patel, Snehal G. ; O’Sullivan, Brian ; Brandwein, Margaret S.; Ridge, John A., Migliacci, Jocelyn C.; Loomis, Ashley M.; Shah, Jatin P. (March 2017). CA: A Cancer Journal for Clinicians. 67(2): 122-137.

Ryan, D.P., Hong, T.S. and Bardeesy, N., 2014. Pancreatic adenocarcinoma. New England Journal of Medicine, 371(11), pp.1039-1049.

Scells, H., Zuccon, G., Koopman, B., Deacon, A., Azzopardi, L. and Geva, S., 2017, November. Integrating the framing of clinical questions via PICO into the retrieval of medical literature for systematic reviews. In Proceedings of the 2017 ACM on Conference on Information and Knowledge Management (pp. 2291-2294). ACM.

Treadwell JR, Zafar HM, Mitchelle MD, Tipton K, Teitelbaum U, Jue J. Imaging Tests for the diagnosis and staging of pancreatic adenocarcinoma: A Meta-Analysis. Pancreas. 2016 Jul. 45 (6): 789-95.

Wang, N., Hailey, D., Yu, P., 2014. A review of data quality assessment methods for public health information systems. International Journal of Environmental Research and Public Health, 11(5), pp. 38-43.

Westwood, M.E., Mallet, S., Deeks, J. J., Rutjes, A. W. S., Reitsma, J. B., Whiting. P. F., et al. 2011, “QUADAS-2: A revised tool for the quality assessment of diagnostic accuracy studies”, Annals of Internal Medicine, vol. 155, no.8, pp.529

Whiting, P.F., Rutjes, A.W., Westwood, M.E., Mallett, S., Deeks, J.J., Reitsma, J.B., Leeflang, M.M., Sterne, J.A. and Bossuyt, P.M., 2011. QUADAS-2: a revised tool for the quality assessment of diagnostic accuracy studies. Annals of internal medicine, 155(8), pp.529-536.