Family History of Bowel Cancer?

Having a close relative diagnosed with bowel cancer may increase your own risk of developing bowel cancer.

Understanding your family history can help determine when screening should begin and whether colonoscopy may be appropriate.

Many people with a family history are unaware that screening recommendations may differ from the general population.

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Why Does Family History Matter?

Bowel cancer can sometimes occur more frequently within families.

While most bowel cancers occur in people without a strong family history, having affected relatives can increase your risk.

The degree of risk depends on:

  • Which relative was affected
  • Their age at diagnosis
  • How many relatives were affected
  • Whether hereditary bowel cancer syndromes are present

Which Family Members Are Most Important?

First-degree relatives

These include:

  • Mother
  • Father
  • Brother
  • Sister
  • Child

A bowel cancer diagnosis in a first-degree relative is generally more significant than in more distant relatives.

When Might Screening Be Recommended Earlier?

Depending on your family history, screening may be recommended earlier than the standard population screening program.

Examples may include:

  • Parent diagnosed with bowel cancer
  • Multiple relatives affected
  • Relative diagnosed at a young age
  • Family history of advanced bowel polyps

Patients should discuss their individual circumstances with their GP or specialist.

What About Bowel Polyps?

Polyps are small growths that can develop within the bowel.

Most are benign, but some types may slowly develop into bowel cancer over many years.

A family history of advanced polyps may also be relevant when determining screening recommendations

Hereditary Bowel Cancer Syndromes

A small proportion of bowel cancers are associated with inherited conditions such as:

  • Lynch Syndrome
  • Familial Adenomatous Polyposis (FAP)

These conditions are uncommon but can significantly increase bowel cancer risk.

Your doctor may recommend further assessment if your family history suggests an inherited syndrome.

What Symptoms Should I Watch For?

Regardless of family history, symptoms that should be discussed with your doctor include:

  • Blood in the stool
  • Unexplained iron deficiency anaemia
  • Persistent change in bowel habit
  • Ongoing abdominal pain
  • Unexplained weight loss

Can Colonoscopy Help?

Colonoscopy is considered the most accurate test for examining the lining of the bowel.

During colonoscopy:

  • Polyps can be detected
  • Polyps can often be removed
  • Biopsies can be taken if required
  • Bowel cancer can be investigated

Early detection and removal of precancerous polyps can help reduce future bowel cancer risk.

Family History Risk Assessment

Consider discussing screening with your GP if:

☐ A parent has had bowel cancer

☐ A sibling has had bowel cancer

☐ Multiple family members have had bowel cancer

☐ A relative was diagnosed at a young age

☐ There is a family history of advanced bowel polyps

What Should I Do Next?

Step 1

Understand your family history.

Step 2

Discuss your risk with your GP.

Step 3

Determine whether specialist review or colonoscopy may be appropriate.

Step 4

Follow the screening plan recommended by your healthcare team.

Looking for a Specialist?

DirectColonoscopy.com.au helps patients and GPs identify participating specialists providing direct access colonoscopy services across Australia.

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Frequently Asked Questions

My father had bowel cancer. Should I have a colonoscopy?

Possibly. The appropriate screening approach depends on factors such as your age and your father’s age at diagnosis. Discuss your individual circumstances with your GP or specialist.

My grandparent had bowel cancer. Am I high risk?

Not necessarily. Risk varies depending on which family members were affected and how many relatives have been diagnosed.

What if more than one relative has bowel cancer?

Multiple affected relatives may increase the likelihood of an inherited predisposition and should be discussed with your doctor.

Can I still develop bowel cancer without symptoms?

Yes. Early bowel cancer and bowel polyps often cause no symptoms, which is why screening is important.

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