Gastrointestinal (GI) cancer incorporates a diverse set of cancers. This includes malignant cancers of the digestive
tract and organs of digestion including oesophagus, stomach, small intestine, bowel, pancreatic, bile duct and liver
cancer. Cancer of the digestive tract and associated organs is responsible for more cancer deaths than any other body
system.
Bowel cancer (colorectal cancer) is the most significant of the GI cancers in New Zealand. This is because it is the
second highest cause of cancer death in New Zealand with over 1200 New Zealanders dying of this cancer every year or
approximately 3 people per day. New Zealand has higher rates of bowel cancer compared to many other western countries.
The good news is, that if detected early, bowel cancer is curable.
So how can bowel cancer be detected early? It is well established that bowel cancer forms in polyps (growths) which if
left in the bowel can become cancerous. Polyps are in the most part easily removable during a camera test known as
colonoscopy and this can prevent people getting bowel cancer! It is also known that bowel screening tests can help
detect polyps and bowel cancer early and reduce the number of deaths from this cancer. New Zealanders are fortunate that
after a successful bowel screening pilot, the Ministry of Health is rolling out bowel cancer screening throughout the
country. This is free for New Zealanders between 60 and 74 years and involves a person dipping a test stick into their
bowel motion or poo. The laboratory then tests this for tiny traces of blood which if detected may mean that person has
a dangerous polyp or a cancer in their bowel.
Other ways to decrease the risk of most GI cancers, particularly bowel cancer, include lifestyle changes and identifying
individuals who might have an increased chance of getting cancer. The Familial Gastrointestinal Cancer Service assesses
whether a family has an increased risk of developing cancer, and co-ordinates the care of people with high risk
syndromes.
Some risk factors for GI cancers cannot be modified (for example getting older, and genetics) and some lifestyle factors
can be modified. Many life-style factors have been linked to GI cancer particularly bowel cancer. This includes obesity
(especially abdominal fatness), inactivity, smoking, moderate or high alcohol intake and a less plant based diet higher
in meats especially preserved meats such as bacon and salami. Based on epidemiological studies it may be possible to
reduce the rates of colon cancer by as much as 70% if everyone in New Zealand adhered to healthier life choices.
Treatment of GI cancers is changing with exciting and promising new drugs for many GI cancers. The future seems to lie
in the so called designer drugs aimed at harnessing chemicals released by the immune system, or starving tumors by
blocking the growth of blood vessels. Such innovations require ongoing funding for research into GI cancer.
The bottom line: see your doctor if you have concerning symptoms or a concerning family history, decrease your own risk
of GI cancer by leading a healthier lifestyle and take part in the NZ bowel screening programme.
Further information can be found at www.nzfgcs.co.nz & https://www.timetoscreen.nz/bowel-screening/doing-the-bowel-screening-test/
Guidelines for managing people with higher risks of bowel cancer. can be found at https://www.health.govt.nz/system/files/documents/publications/colorectal-cancer-surveillance-guidance.pdf