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Wednesday 24 April 2019
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Expert analysis: Calling attention to colorectal cancer

Colorectal cancer is Europe’s second biggest cancer killer, claiming the lives of nearly 200,000 people across the continent each year. Current trends predict that the burden of colorectal cancer could increase by 12% by 2020, affecting 502,000 Europeans a year by 2020.1
 
Colorectal cancer screening acts as the most effective method in improving prognosis and preventing the disease. The heavily time-dependent nature of colorectal cancer means that there is a much higher chance of survival the earlier the cancer is detected, as early cancers have a survival rate of 90-95%.2 Despite the obvious threat posed by the disease and the possible advances screening programmes hold, access to effective screening programmes and treatment differs significantly across Europe.
 
Currently, eastern Europe is falling behind the west in the quality and efficacy of screening programmes and quality assurance mechanisms in these countries are not widespread. Low participation rates in screening programmes are frequent in eastern Europe, with many countries falling short of the 65% participation rate considered necessary by the European Commission. The inequality of access is highlighted when comparing the participation rates between Hungary and the Netherlands; whilst the Netherlands has attained a 72% participation rate, Hungary has a participation rate of just 0.6%. These inequalities act as an example for the insufficient efforts made by many governments across Europe to make colorectal cancer screening an accessible service and a key public health concern. European governments should be aiming to offer appropriate screening tests to the whole target population to detect colorectal cancer when it is at an early stage and before symptoms begin.
 
Despite colorectal cancer screening programmes attaining an established presence across different parts of Europe, many countries are yet to transition to the most effective and accurate screening methods. Presently, a number of European countries are still using the faecal occult blood test (gFOBT). The test relies on three samples that are tested for simple oxidation which can be compromised by the influence of dietary haemoglobin, leading to a number of false positives. The recently introduced faecal immunochemical test (FIT) is more advanced than the traditional gFOBT method. It is easier to perform, as it requires only a single stool sample to check for the presence of blood and has a simple collection device. Studies have revealed the increased sensitivity of FIT, resulting in increased cancer detection. FIT has also been viewed as a more acceptable test by members of the public due to the ease of collection.3 This method has also been demonstrated to have an increased participation uptake, and is therefore a more desirable alternative to the gFOBT method. In the Netherlands, for example, the participation rate for FIT was 12% higher than that for gFOBT.4 In a FIT-based screening program, colorectal cancers can be detected at an earlier stage than through symptoms. All FIT-positive participants are advised to undergo a colonoscopy, during which these cancers, as well as potentially cancerous polyps, will be identified. After diagnosis the optimal treatment-strategy will be chosen, of which one is endoscopic removal. An enhanced understanding of the genetic and epigenetic changes that are behind the formation of CRC aims to identify molecular markers for accurate and non-invasive screening tests. The addition of molecular markers to the FIT method could optimise screening accuracy in the future.
 
In the struggle to combat colorectal cancer, novel and effective treatments are urgently required. The surgical resection of tumours currently represents the best strategy to improve patient survival rates, however patients still have a high risk of developing metastases. Additionally, chemotherapy is not optimally beneficial for all patients who are diagnosed with advanced colorectal cancer due to factors like poor efficacy, drug resistance and severe side effects.5 In recent years it has become clear that not all colorectal cancers are the same, and that the molecular characteristics of the tumours should be taken into account. Molecular differences mean that a ‘one-size-fits-all’ approach to treatment is not optimal, leading to an increased interest in a personalised method of treatment.6 Personalised colorectal cancer treatment utilises information about a person’s genes, proteins and environment to prevent, diagnose and treat the disease. The ability to use molecular screening to characterise tumours and target patients who are likely to benefit from personalised treatment, holds great potential for positive patient outcomes. Further research into this mode of tailored treatment could have a transformative effect on the concerning upward trend of colorectal cancer treatment modalities and reduced mortality rates.
 
Aligning with the move towards more personalised forms of treatment, recent developments in artificial intelligence (AI) may also aid the detection and treatment of tumours. The advent of AI represents an exciting forefront in cancer prevention. An endoscopic system powered by AI has been shown to automatically identify colorectal adenomas and early cancers during colonoscopy. The computer-aided diagnostic system might also use endoscopic, or a more detailed endocytoscopic imaging to analyse the polyp, comparing it to other images, allowing prediction of lesion pathology in less than a second.7 The use of AI holds the possibility of aiding the early identification of potential cancerous adenomas, helping to reduce the incidence and mortality of colorectal cancer.
 
The early detection of colorectal cancer or potentially cancerous polyps is the most vital action in reducing colorectal cancer incidence and mortality. However, a healthy lifestyle can also act as an integral measure. Alarming figures have shown that European colorectal cancer rates in young adults is increasing by 6% per year, which has been linked to poor diets, sedentary lifestyles and obesity, with over half of he EU population being considered overweight.8,9 The promotion of healthy lifestyles, reduced alcohol consumption and a reduction of the European population’s meat consumption should become a strong focus of European policy. An enhanced public understanding of healthy lifestyle options is an essential measure in mitigating the threat of colorectal cancer.
 
The public’s participation in screening programmes also plays a crucial role in the success of early detection. Responding to invitations and completing the at-home tests that are available across many parts of Europe could greatly reduce the incidence and mortality rates that are attributable to colorectal cancer. Health professionals can also act as proactive figures in prevention and early detection. Research has suggested that the lack of colorectal cancer screening recommendations made by a doctor is a key barrier to screening uptake.10 As one of the most accessible authorities on health matters to the general public, healthcare professionals should be broaching the subject of screening with eligible adults and extolling the benefits of colorectal cancer screening. The education of members of the public about the advantageous aspects of colorectal cancer screening by trusted healthcare professionals will also help expel the negative connotations associated with the screening process. The initial gFOBT or FIT screening methods are largely painless and various initiatives are being undertaken across Europe to improve the quality of colonoscopies and reduce its burden. In order to improve detection rates, colorectal cancer screening must become a normative and essential aspect of healthcare across Europe that is dissociated from feelings of fear and embarrassment.
 
Ultimately, the most effective and vital component in the battle against colorectal cancer is detecting its presence as early as possible, as colorectal cancer symptoms only become prevalent in the later stages of the disease. A harmonisation of screening programmes and increased participation rates needs to become a key priority for governments across Europe.
 
References
  1. International Agency for Research on Cancer (IARC). 
  2. NCBI. 2017. Global patterns and trends in colorectal cancer incidence and mortality. (ONLINE). Available at: https://www.ncbi.nlm.nih.gov/pubmed/26818619. (Accessed 5 February 2019). 
  3. NCBI. 2016. The effectiveness of FOBT vs. FIT: A meta-analysis on colorectal cancer screening test. (ONLINE). Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4972062/ (Accessed 5 February 2019). 
  4. United European Gastroenterology. 2016. One in four cases of CRC diagnosed within two years of a negative screening result. (ONLINE). Available at: https://www.ueg.eu/press/releases/ueg-press-release/article/one-in-four-.... (Accessed 5 February 2019).
  5. United European Gastroenterology. 2016. Experimental models of colorectal cancer. (ONLINE). Available at: https://www.ueg.eu/education/latest-news/article/article/experimental-mo.... (Accessed 5 February). 
  6. NCBI. 2013. The role of personalized medicine in metastatic colorectal cancer: an evolving landscape. (ONLINE). Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3756633/. (Accessed 5 February 2019). 
  7. United European Gastroenterology. 2017. Artificial intelligence: is this the future of early colorectal cancer detection? Available at: https://www.ueg.eu/press/releases/ueg-press-release/article/ueg-week-art.... (Accessed 5 February 2019). 
  8. United European Gastroenterology. 2018. European colorectal cancer rates in young adults increasing by 6% per year. (ONLINE). Available at: https://www.ueg.eu/press/releases/ueg-press-release/article/ueg-week-eur.... (Accessed 6 February 2019). 
  9. Eurostat: Statistics Explained. 2014. Overweight and obesity- BMI statistics. (ONLINE). Available at: https://ec.europa.eu/eurostat/statistics-explained/index.php/Overweight_.... (Accessed 6 February 2019).
  10. United European Gastroenterology. 2014. Family doctor intervention is crucial in the fight against Europe’s second biggest cancer killer. Available at: https://www.ueg.eu/press/releases/ueg-press-release/article/family-docto.... (Accessed 6 February 2019).
About the author and UEG
Professor Evelien Dekker, colorectal cancer expert, is a member of the European Gastroenterology (UEG) Public Affairs Committee. Professor Dekker’s expertise derives partly from the Netherlands, in which pilot-studies and implementation studies were conducted to investigate the most effective ways of organising the programme and encouraging enrolment. The Netherlands currently has the highest rate of participation in colorectal cancer screening programmes in Europe.
 
UEG is a professional non-profit organisation encompassing all the leading European medical specialist and national societies focussing on digestive health. UEG aims to reduce the burden of digestive diseases through improved disease prevention, diagnosis, cure and raised awareness of their importance.