April marks Bowel Cancer Awareness month, a time of year when we are reminded to be vigilant of the signs and symptoms of this common cancer. Along with other organisations, Cancer Research Wales is helping to address some of the challenges and opportunities as they relate to bowel cancer in Wales.
Bowel cancer is the fourth most common cancer diagnosed in Wales, yet the second leading cause of cancer mortality with over just 900 deaths each year. However, there is much that can be done to reduce the impact of this largely preventable disease through awareness of symptoms, participation in screening, early diagnosis and right lifestyle choices.
Early diagnosis of bowel cancer will be a critical aspect for reducing mortality rates. For example, most patients with early stage disease (stage I) can be treated successfully, with five year survival rate exceeding 90%. However, this falls to below 10%, if the cancer is diagnosed at stage IV.
The latest data available from the Wales Cancer Intelligence Surveillance Unit, show that almost half of all cases of bowel cancer in Wales are diagnosed at an advanced stage (III and IV). With the real figure likely to be higher, given that the stage of up to one-fifth of bowel cancers cannot be determined due to various factors, including poor health.
Increased public participation in National Bowel Cancer Screening Programmes will be important for arresting these unfavourable figures, as they represent an essential and extremely effective intervention for identifying early disease, often in patients who show no usual symptoms. International studies show mortality rates from bowel cancer can be reduced by 25% when screening targets are met. Unfortunately, Wales as a nation, has some of the lowest rates of screening uptake, with only just over half of all sample screening kits returned – well below the 60% target. Collectively, we need to do better.
In Wales, bowel cancer screening starts at 60, with people invited to participate when they receive a kit, known as the Faecal Occult Blood Test (FOBT), through the post. Interestingly, some support groups are calling for screening to begin at 50, as is the case in Scotland, and with around 250 cases of bowel cancer occurring in people between ages 50 and 60 annually here in Wales, it is easy to understand why.
The Wales Bowel Cancer screening campaign aims to increase awareness and participation in FOBT. Evidence suggests that fear of the test outcome; not having any symptoms, a perceived low risk of bowel cancer and concerns about the practicalities and cleanliness of the screening test all act as barriers to participation.
A real opportunity to improve bowel cancer screening participation in Wales is emerging with the much awaited introduction of the new faecal immunochemical test (FIT) later this year or next. This new test is more sensitive and reliable as it directly measures a component of blood, called haemoglobin, in the stools. As the test usually requires the collection of only one stool sample, and with no restrictions placed on diet as interference from certain food types is negated, trials have shown an increased participation of up to 9%.
Although this is welcomed – are we prepared service-wise? Diagnostic capacity in Wales is required to meet the expected increased demand if survival rates for cancer are to be reduced. There is already great pressure on endoscopy units, and unfilled radiology and pathology posts all have the potential to add to further delays in diagnosis.
In light of this, Welsh Government has pledged to train more radiologists with recent funding for a £3.4 million new state-of-the art-National Imaging Academy for Wales in Bridgend, and has also provided extra investment for infrastructural support for stretched endoscopy units in North Wales.
Primary care has a vital role to play in early diagnosis as it is estimated that one in five GP appointments are for gastrointestinal symptoms. The symptoms of bowel cancer are often non-specific and include changes in bowel habits, blood in stools, unintentional weight loss, tiredness and fatigue. These symptoms are often common in regular conditions like Crohn’s Disease, ulcerative colitis, celiac disease, diverticulitis and simple Irritable Bowel Syndrome.
New point of care tests that are more precise for bowel cancer, rely less on symptoms, and can be readily used in GP surgeries, will represent a major advancement in early diagnosis. Cancer Research Wales has been working closely with Professors Dean Harris and Peter Dunstan at Swansea University on a new simple and less invasive blood test for bowel cancer that meets these criteria.
The test senses an array of tumour associated molecules that have been secreted into the blood, akin to a molecular fingerprint. During the initial stages of development, the test was shown to have an accuracy approaching that of a colonoscopy. Initial trials of the test will soon take place across South Wales’ GP surgeries. There is real future potential to provide upfront reassurance to prevent unnecessary colonoscopy procedures, whilst ensuring more rapid referral and further investigations, for those that really need it.
It is estimated that only 30-40% of patients referred for colonoscopy as a result of an unfavourable FOBT result during screening, are found to have significant polyps or cancers. More prudent tests such as the one being developed by the scientists at Swansea, has the potential to transform the current diagnostic pathway for bowel cancer in Wales.
There is still much we can do ourselves to reduce the impact of bowel cancer, including an awareness of symptoms, participation in screening, and adopting a healthy lifestyle. The large differences in both the incidence and mortality rates of bowel cancer between some regions of Wales is thought to predominantly arise from poor lifestyle choices and increasing obesity.
Alcohol and smoking both have a detrimental effect on bowel health. Recommendations have also been made to limit the intake of processed deli meats like bacon, ham, sausages and red meats like beef, lamb and venison, to 70g a day, as these are recognised by the World Health Organisation as cancer causing agents when eaten in large and frequent quantities.
Meanwhile, a diet rich in fruit, vegetables, fibre, and replacement of red meats with white meats such as chicken and fish, all help decrease our chances of developing bowel cancer, particularly when combined with regular exercise and maintenance of a healthy body weight.
