Bowel cancer: Who’s at risk, the symptoms to watch out for, and how to get tested

At an early stage, bowel cancers are one of the easiest to identify and treat. Photo / 123RF

The BBC newsreader George Alagiah has died aged 67 from bowel cancer. Alagiah was first diagnosed with stage 4 bowel cancer in 2014, and had campaigned for better awareness of the disease. In May, he shared a tweet urging more people to take up NHS bowel cancer screening kits.

Bowel cancer is a general term for cancer that begins in the large bowel, which is made up of the colon and the rectum. It is sometimes called colorectal cancer. Nearly 43,000 people are diagnosed in the UK each year, making it the fourth most common cancer and the second-biggest cancer killer.

At an early stage, bowel cancers are one of the easiest to identify and treat, says Prof Sina Dorudi, a consultant colorectal surgeon at the Princess Grace Hospital, part of HCA Healthcare UK. She explains, “The cancer usually starts as benign polyps which grow on the wall of the bowel. If these aren’t spotted, then certain types can turn cancerous and develop into a tumour. It is important to emphasise that if the tumour is caught early, in most cases it can be removed in full, with surgery.”

Who is at risk?

Put simply, “anyone could be at risk,” says Genevieve Edwards, the chief executive of Bowel Cancer UK. “Bowel cancer is more common in people who are over 50. But younger people can and do get diagnosed with it, too. So really, anyone with any symptoms that are concerning – the ‘red flag’ symptoms – should go and talk to their GP.”

More than nine in 10 cases of bowel cancer are diagnosed in people aged 50-plus. However, cases in younger people are rising: around 2,500 cases are diagnosed in under-50s each year. If you have a first-degree relative (a parent, sibling, son or daughter) who was diagnosed with bowel cancer, this increases your risk.

There are other lifestyle factors that can increase your risk of developing the disease; in fact, 54 per cent of cases are thought to be preventable. Obesity is a key risk factor, responsible for around 11 per cent of bowel cancer cases in the UK. A poor diet also raises your risk: studies have shown that eating too much red or processed meat causes around 13 per cent of cases, according to Cancer Research UK. The World Health Organisation ranks bacon, ham and sausages up with cigarettes as a major cause of cancer.

A diet rich in fibre reduces your risk, and eating too little fibre is linked to 30 per cent of bowel cancer cases. Drinking alcohol and smoking are both risk factors, responsible for 6 and 7 per cent of cases respectively.

What is the survival rate?

Bowel cancer is curable if it is caught early; 97 per cent of people survive bowel cancer diagnosed at stage 1, says Edwards. Survival rates drop with each stage of the disease: according to Cancer Research, only 10 per cent of people with stage 4 bowel cancer will survive their cancer for five years or more after they’re diagnosed, unless it has spread into the liver and a surgeon can remove it, in which case the survival rate rises to 40 per cent.

What are the symptoms of bowel cancer?

The “red flag” symptoms of bowel cancer are: bleeding from your bottom or blood in your stool; a persistent and unexplained change in bowel habit; unexplained weight loss; extreme tiredness for no reason; and a pain or lump in your tummy.

“Most people with these symptoms don’t have bowel cancer, but if it is bowel cancer, you need to get diagnosed as quickly as possible,” says Edwards. “It’s treatable if it’s diagnosed early, so if you go straight to your GP, rule out bowel cancer first and fast. And if it is bowel cancer, of course, the earlier you’re diagnosed, the more likely it is that you can be successfully treated.”

Screening for bowel cancer

In New Zealand, Time to Screen is a free government-run programme to help detect bowel cancer. It’s offered every two years to people aged 60 to 74 years who are eligible for publicly funded health care and Māori and Pasifika will be invited to participate in bowel screening from 50 years old.

New Zealanders will receive an invitation letter when it’s their turn to be screened, a consent form, and a free bowel screening kit.

Those not eligible for the programme who may have concerns about their bowel health, or anyone who may have symptoms of bowel cancer, are advised to see their GP for further advice and testing without delay.