Imagine this scenario: Sarah, aged 35, presents with mild abdominal discomfort but no concerning symptoms. Examination is unremarkable, blood tests are normal and imaging reveals no obvious abnormalities. Despite the reassuring results, she still doesn’t feel right.

The turning point comes when Sarah’s GP asks her to find out more about her family’s medical history. Sarah learns that an uncle had bowel cancer when he was quite young, her grandmother had endometrial cancer, and her mother has a history of bowel polyps.

Ultimately, Sarah’s mother is diagnosed with a hereditary cancer syndrome.

For patients like Sarah, taking a detailed family history can change the course of their lives—and improve health outcomes for generations—through identifying the need for closer monitoring and preventative measures.

Recognising the red flags

Family history-taking can uncover disease clusters that may otherwise go unrecognised.

Consider which family members have had these cancers, the types of cancers, and when they were diagnosed.

Important clues include cancers that occur at a young age, affect multiple relatives or recurrence across successive generations — as well as a combination of cancer types within the family, says Dr Michael Bogwitz, a genetic counsellor and lead of Cancer Council Victoria’s Family Cancer Program.

“All of this tied together makes a difference when you’re assessing the risk your patient might be at and how far to go with investigations and referral,” Dr Bogwitz says.

For example, Lynch syndrome is the most common inherited cause of colorectal cancer, and it’s also associated with endometrial cancer and increased risk of ovarian and other cancers.

In Sarah’s case, the combination of bowel cancer, endometrial cancer and bowel polyps within her family is significant.

Benefits that extend to multiple people

Associate Professor Alison Trainer, a clinical geneticist at the Peter MacCallum Cancer Centre and Melbourne Health, says taking a family medical history can have a much wider impact than people may realise.

“Think of your patient as one part of a complex DNA puzzle. And that DNA encodes a lot of the health issues they may encounter during their life,” she says.

“You really only see the whole picture if you know about the medical history of as many relatives as possible. And that allows a diagnosis in one individual to provide the possibility of disease prevention in another.”

Who should be referred to a Familial Cancer Centre?

If a concerning family history is identified through risk assessment using clinical guidelines the next step involves determining the best candidate for further assessment—which may not necessarily be your patient.

The most likely people to have a genetic cancer syndrome (within a family tree of many cancer diagnoses) are the living family members who’ve actually had a cancer diagnosis. That’s why referring the affected family member to a familial cancer centre can provide “a better and more personalised risk assessment” for the wider family, Dr Bogwitz says.

In Sarah’s case, her mother was the best candidate for further assessment since she was more closely related to affected family members who had already passed away. (Sarah’s mother underwent genetic testing and was found to have a pathogenic variant associated with Lynch syndrome.)

Clinical genetic or familial cancer services conduct detailed reviews of the family cancer history and how the referred person’s cancer diagnoses fit within that context. This will inform the next steps.

It’s also important not to automatically assume a genetic fault is responsible.

Cancer is common, and there may not be a genetic component to clusters, Dr Bogwitz adds. “And even in families where we find that there is something inherited going on, there can be cancers that are not part of that inherited condition.”

Genetic testing provides a chance to change future outcomes

Referral to a familial cancer service can prompt anxiety, but it can help to frame it as an opportunity to gain knowledge and reduce risk.

“A genetic test does not change your risk. It reveals your risk. And as a risk is revealed, it can be managed.” – Associate Professor Alison Trainer

Patients will receive genetic counselling before testing, so they understand that finding a genetic fault doesn’t predestine other family members to develop cancer, Associate Professor Trainer says.

Finding a genetic fault is like a “bifurcation in the road,” she says. “It provides new opportunities to manage the risk and inform other wider life decisions.”

For example, assisted reproduction technology can prevent the gene fault from being passed on to the next generation.

Depending on the genetic variant, early detection and proactive management may be offered – along with strategies to reduce risk. For example, someone with a germline MSH2 genetic variant causing MSH2-related Lynch syndrome would be recommended to have regular colonoscopies from a younger age, and low dose aspirin to reduce the risk of polyps. Preventive surgeries and lifestyle changes to reduce the risk of other cancers may also be recommended.

Putting it in perspective

It’s useful to remember that we all carry genetic faults, Associate Professor Trainer says.

“We all sit with about 10 to 20 gene faults, some of which we inherit, some of which we make ourselves in utero,” she says. “The majority of these, however, are not in genes that impact a person’s health, so they just carry on silently.”

Telling relatives about a genetic fault can be a challenge, and not everyone responds positively at first.

“But what we find is that over time, people digest the information, they think about their own children, they think about the impact it may have,” Associate Professor Trainer says. “Over time, we find family members slowly contact us. But it can take up to two years from first being told about the familial gene fault.”

“We often tell individuals they cannot determine how their relative responds to the information, but it is their responsibility to at least let them know that that test is available so they can make their own decisions in their own time.”

Steps for assessing family history

Ask and record family medical history

Ask patients about their family medical history. This RACGP resource includes type of questions to ask and step by step instructions for drawing a pedigree, which can help identify patterns of inheritance.

Risk assess

Use these eviQ guidelines or for breast and ovarian cancer you can use the IPrevent tool to assess the pedigree to identify the patient’s level of risk and whether they should be referred for a cancer genetics assessment.

Refer those at increased risk

If the guidelines suggest the patient is at high risk, refer to a familial cancer centre (FCC) or clinical genetics service for further assessment. Cancer Council has also developed this checklist for referral to ensure you’ve included all the key information.

Set realistic expectations

FCCs offer counselling, medical advice and information – and they can provide Medicare-funded genetic testing to eligible patients. However, not everyone who is referred will be eligible for genetic testing, so it’s important that patients know the service will assess their eligibility on an individual basis.

Keep family history up-to-date

Review every 12 months, including any updates such as new diagnosis among family members.

Key takeaways

• Family history is a powerful tool for identifying patients at risk of hereditary cancer syndromes and other genetic conditions
• Red flags include early-onset cancers, multiple affected relatives, cancers occurring across generations and recognised cancer clusters
• Not all clusters will have a genetic component
• If hereditary cancer risk is suspected, you don’t need comprehensive family history information to refer – but you do need to demonstrate the rationale for assessing the patient as high risk. See Cancer Council Victoria’s FCC referral checklist
• The best person to test may be an affected relative rather than the patient
• Familial cancer services can guide family risk assessment, testing, surveillance and prevention

Helpful resources

Cancer Institute NSW eviQ | Evidence-based Australian genetics and familial cancer information

Cancer Council Victoria | Familial cancer information and referral guidance for health professionals

Inherited Cancers Australia | Peer support and resources for individuals and families affected by inherited cancer syndromes