Did you know that if you are overweight or obese, you have a higher risk of developing bowel cancer? June is Bowel Cancer Australia’s Bowel Cancer Awareness Month. Australia has one of the highest rates of bowel cancer in the world, and year on year it’s increasing. As both general surgeons who operate on the gastrointestinal tract, and specialist bariatric surgeons, this issue is an important one for us. We take a look at the risk factors for bowel cancer, and the symptoms you need to be aware of which could save your life.

obesity risks for bowel cancer

The Facts about Bowel Cancer

According to Bowel Cancer Australia at present 14,962 people are diagnosed with bowel cancer in Australia every year. By 2020, it’s predicted we will reach 20,000. It is also the second biggest cancer killer, claiming 4,162 lives every year. This is because often the symptoms go undiagnosed until it’s too late.

What is Bowel Cancer?

Bowel cancer is also known as colorectal cancer. Many growths in the colon or rectum begin as polyps. These are benign lumps on the wall or lining of the bowel. Whilst many are harmless, some can turn into malignant growths.

So What Are The Risk Factors for Bowel Cancer?

Your chances of developing bowel cancer may increase if you:

  • Have a family history of bowel cancer, or inherited gene mutations
  • Are over 50 (although you can never be too young).
  • Have inflammatory bowel diseases and ulcerative colitis
  • Obesity

As well, a whole host of other diet and lifestyle factors are risk factors for bowel cancer, such as:

  • High red meat consumption
  • Alcohol consumption
  • Smoking

Bowel Cancer Australia states your risk of bowel cancer can increase by 2 per cent per BMI unit over your optimal weight.

“Studies show convincing evidence that:
i. greater body fatness is a cause of bowel cancer (2% increased risk per kg/m2);
ii. abdominal fatness is a cause of bowel cancer (17% increased risk with increased waist to hip ratio)

Bowel Cancer Australia Increased Bowel Cancer Risk

For example, if you are a BMI of 40, then you are 30% more likely to develop colorectal cancer than someone who is not overweight.

Obesity and Cancer Rates.

In addition to being one of the risk factors for bowel cancer, being obese also increases your risk of developing other cancers. According to a U.S. National Cancer Institute report on Obesity and Cancer, obesity has been shown in observational studies to increase your risk of developing:

  • Endometrial cancer
  • Esophageal adenocarcinoma
  • Gastric cardia cancer
  • Liver cancer
  • Kidney cancer
  • Multiple myeloma
  • Meningioma
  • Pancreatic cancer
  • Colorectal cancer
  • Gallbladder cancer
  • Breast cancer
  • Ovarian cancer
  • Thyroid cancer

What are the Bowel Cancer Symptoms I Need to Watch Out For?

According to the Cancer Council of Australia, not all bowel cancers show symptoms and experiencing symptoms does not necessarily mean you have bowel cancer. However, you should see your doctor if you notice:

  • bleeding from the back passage or any sign of blood after a bowel motion;
  • a change in usual bowel habit, such as straining (constipation) to go to the toilet or loose motions (diarrhoea)
  • abdominal pain or bloating;
  • weight loss for no obvious reason, or loss of appetite
  • symptoms of anaemia – including unexplained tiredness, weakness or breathlessness.

How Do I Decrease My Risk For Bowel Cancer?

Overall, a healthy lifestyle is your best defence against bowel cancer. Giving up smoking, reducing your intake of alcohol, and adopting an exercise routine can decrease your risk. As well, improving your diet, including plenty of fibre-rich foods and reducing the level of red and processed meat you consume can help.

If you are overweight or obese, a serious talk with your doctor on the best approaches to weight loss will help you decrease your risk of bowel cancer, and indeed, many cancers. For those people who are at high risk of obesity-related diseases, or who are morbidly obese, bariatric surgery can be a life-saving option. You can find out more about whether you may be a candidate for weight loss surgery here.

Early Detection Can Save Your Life

“90 per cent of bowel cancer cases can be treated successfully if found early. Fewer than 40% are detected early,” Bowel Cancer Australia.

Regardless of your age, if you are unsure if your bowel symptoms are normal, book a check-up with your G.P. A bowel cancer screen test is widely available and is worth asking for if you have symptoms or a family history, or for anyone over 50 years of age.

For more information, a great place to start is the Bowel Cancer Australia website, and of course have a chat with your G.P. about your risk factors, family history and symptoms.