Hereditary cancer syndromes: recognition and referral in AU general practice

Hereditary cancer syndromes account for approximately 5–10% of all cancers in Australia, arising from germline pathogenic variants in tumour suppressor genes or DNA repair genes that follow predominantly autosomal-dominant inheritance. For most of these conditions, identifying a carrier before cancer develops — or early in the disease course — allows risk-reducing interventions that substantially reduce mortality. The general practice setting is where the initial recognition happens: a well-taken family history at a health check, an early-onset cancer in a young patient, or a patient whose sibling has just been found to carry a BRCA variant are all entry points to the clinical genetics pathway.

Australian access to genetic testing has expanded significantly. The MSAC 1504 decision in 2024 broadened MBS-funded panel testing to include more than fifteen clinically actionable genes for affected probands meeting eligibility criteria, and cascade testing of first-degree relatives is publicly funded once a proband’s variant is identified. The eviQ Cancer Genetics platform — run by Cancer Institute NSW — is the Australian clinician’s primary reference for up-to-date referral criteria, surveillance protocols, and risk-reduction recommendations.

A. Core clinical — the AU general-practice framework

Major hereditary cancer syndromes

The following syndromes are the most clinically important in Australian general practice:

Syndrome	Genes	Key cancers	Distinguishing features
HBOC (Hereditary Breast and Ovarian Cancer)	BRCA1, BRCA2; PALB2, ATM, CHEK2, RAD51C, RAD51D	Breast (female + male), ovarian, fallopian, peritoneal, prostate, pancreatic	Early-onset breast; bilateral breast; male breast; triple-negative breast ≤60; high-grade serous ovarian; Ashkenazi founder mutations
Lynch syndrome (HNPCC)	MLH1, MSH2, MSH6, PMS2, EPCAM	Colorectal, endometrial, ovarian, gastric, urothelial, small bowel, biliary, brain, sebaceous skin	Early-onset CRC; right-sided predominance; Amsterdam II criteria; MSI-high / MMR-deficient tumour; Muir-Torre sebaceous neoplasms
FAP (Familial Adenomatous Polyposis)	APC	Colorectal (100% penetrance untreated by age 40), duodenal, thyroid	>100 colonic adenomas; CHRPE on fundoscopy; desmoid tumours
MUTYH-Associated Polyposis	MUTYH (autosomal recessive)	Colorectal	10–100s polyps in 30–50s; biallelic mutations
Li-Fraumeni syndrome	TP53	Sarcoma, brain (choroid plexus), breast, leukaemia, adrenocortical carcinoma	Multiple primaries; childhood or early adult onset; sarcoma is the sentinel tumour
Cowden / PHTS	PTEN	Breast, thyroid, endometrial	Macrocephaly; mucocutaneous papillomas; trichilemmomas; GI hamartomas
Peutz-Jeghers	STK11	GI cancers, breast, ovarian (sex cord stromal)	Mucocutaneous pigmentation (lips, perioral, palmar); GI hamartomatous polyps
MEN1	MEN1	Parathyroid, pancreatic NETs, pituitary adenomas	“Three P’s” — parathyroid, pituitary, pancreas
MEN2A / MEN2B	RET	Medullary thyroid carcinoma, phaeochromocytoma, parathyroid (MEN2A); mucosal neuromas, marfanoid (MEN2B)	MTC is often the earliest cancer; RET testing guides prophylactic thyroidectomy timing
Von Hippel-Lindau	VHL	Clear cell renal cell carcinoma, CNS/retinal haemangioblastoma, phaeochromocytoma, pancreatic NET	Multi-organ; family history of renal tumours + cerebellar haemangioblastoma
NF1 / NF2	NF1, NF2	Malignant peripheral nerve sheath tumours (NF1); meningioma, schwannoma (NF2)	Café-au-lait macules; neurofibromas; Lisch nodules (NF1); bilateral acoustic neuromas (NF2)
CDKN2A familial melanoma	CDKN2A	Melanoma (multiple primary), pancreatic	Multiple primary melanomas in family; early onset
BAP1 tumour predisposition	BAP1	Uveal melanoma, cutaneous melanoma, mesothelioma, renal cell carcinoma	Uveal melanoma especially distinctive; family clustering
Hereditary Diffuse Gastric Cancer	CDH1	Diffuse gastric carcinoma (signet ring), lobular breast	Prophylactic total gastrectomy considered for variant carriers

The red flag triad — recognise and refer

Three patterns, based on eviQ criteria, should prompt referral to a Family Cancer Clinic:

1. Early-onset cancer — breast or colorectal cancer diagnosed under 50 years of age; ovarian or endometrial cancer under 40; any cancer under 30 that could fit a named syndrome; sarcoma at any age in a young person.

2. Multiple primaries or strong family history — two or more first-degree relatives with the same or related cancers (especially if early-onset in either); bilateral cancers in one person; more than one primary cancer in a single individual.

3. Syndrome-specific features:

• HBOC: male breast cancer; triple-negative breast cancer at age ≤60; high-grade serous ovarian cancer at any age; Ashkenazi Jewish ancestry with breast or ovarian cancer; bilateral breast cancer.
• Lynch: colorectal cancer with MMR-deficient or MSI-high tumour on pathology; endometrial cancer under 60; multiple Lynch-spectrum cancers (colorectal + endometrial; colorectal + gastric; colorectal + urothelial) in a family.
• FAP: discovery of ≥100 colonic adenomas at any age; family history of FAP.
• Li-Fraumeni: sarcoma in a person under 45 with any first-degree relative with cancer under 45; adrenocortical carcinoma or choroid plexus carcinoma at any age.
• Cowden: macrocephaly combined with breast and thyroid pathology; multiple mucocutaneous papillomas or trichilemmomas.

Three-generation family history

The diagnostic work begins with a systematic three-generation family history covering parents, siblings, children, grandparents, aunts, uncles, and cousins. For each affected relative, document: cancer type, age at diagnosis, whether it was a primary or metastatic cancer, and which side of the family. Update the pedigree at every health check — a family history changes when relatives are diagnosed.

Risk stratification tools for use in general practice include:

• CanRisk / BOADICEA — comprehensive online tool for BRCA and polygenic breast and ovarian cancer risk estimation.
• PREMM5 — Lynch syndrome probability calculator.
• Manchester score — BRCA mutation probability from family history.
• eviQ family history assessment templates — available via the eviQ Cancer Genetics portal.

GP management: recognise, refer, and coordinate

The GP’s role operates in three phases:

Phase 1 — Identification and referral. Take a systematic family history at health assessments, chronic disease management visits, and opportunistically when a new diagnosis arises in the family. Apply eviQ referral criteria. Refer to the local Family Cancer Clinic (FCC) or clinical genetics service for patients meeting criteria. Send a three-generation pedigree, the patient’s personal cancer history, and any prior genetic testing results with the referral.

Phase 2 — Coordination during FCC workup. The FCC provides pre-test genetic counselling, orders the germline multi-gene panel, interprets results, and coordinates cascade testing of relatives. The GP does not order germline genetic testing independently — clinical-grade testing requires pre-test counselling and informed consent processes that must occur at the FCC.

Phase 3 — Long-term surveillance and ongoing general practice. Once a variant is identified and the FCC establishes a surveillance plan, the GP coordinates annual health checks, ensures surveillance appointments are being kept, monitors for new cancers and side effects of chemoprevention, provides mental health support for the psychological burden of genetic risk, and helps communicate risk to family members.

Syndrome-specific risk management

BRCA1/2 (HBOC):

For female BRCA1 carriers, annual breast MRI commences at age 25; annual mammography is added from age 30. For BRCA2 carriers, both modalities begin at age 30. Risk-reducing bilateral salpingo-oophorectomy (RRSO) after completion of childbearing — at age 35–40 for BRCA1, 40–45 for BRCA2 — reduces the lifetime risk of ovarian and fallopian tube cancer by more than 80% and also reduces breast cancer risk. Risk-reducing bilateral mastectomy reduces breast cancer risk by approximately 95% and is discussed as an option after thorough counselling. Tamoxifen or aromatase inhibitors may be offered as chemoprevention where surgery is not chosen.

For male BRCA2 carriers: annual prostate cancer screening from age 40, annual clinical breast examination from age 35, and awareness of the elevated pancreatic cancer risk (surveillance not universally recommended due to uncertain benefit, but may be offered in specialist centres).

Lynch syndrome:

Colonoscopy every one to two years from age 25 (or five years before the earliest CRC in the family). Gynaecological surveillance for endometrial and ovarian cancer (transvaginal ultrasound and endometrial biopsy in selected protocols), with risk-reducing hysterectomy and bilateral salpingo-oophorectomy offered after childbearing is complete. The CAPP2 trial (Lancet 2020) demonstrated that aspirin 600 mg per day for at least two years reduced colorectal cancer incidence by approximately 50% in Lynch syndrome carriers — a benefit that emerged after a five-year follow-up period. This is discussed as a chemoprevention option for adult Lynch carriers (see also B section below). Skin examination for sebaceous neoplasms (Muir-Torre variant of Lynch) and Helicobacter pylori testing and eradication are also recommended.

FAP:

Annual sigmoidoscopy from age 10–12, progressing to full colonoscopy in adolescence. Prophylactic colectomy (total or restorative proctocolectomy) is typically recommended before age 25 — before malignant transformation is expected. Ongoing upper GI endoscopy for duodenal surveillance (interval determined by Spigelman staging) and annual thyroid palpation.

Li-Fraumeni (TP53):

The Toronto surveillance protocol (Villani, Lancet Oncol 2016) includes annual whole-body MRI, annual brain MRI, annual breast MRI from age 20, and colonoscopy every two to three years from age 25. Radiation-based imaging is minimised where possible due to the increased sensitivity of TP53 germline carriers to radiation-induced secondary malignancy. Risk-reducing mastectomy is discussed for female carriers. This protocol is coordinated at specialist Family Cancer Clinics.

Cascade testing:

Once a proband’s pathogenic variant is identified, the FCC coordinates referral and testing of first-degree relatives. Cascade testing is publicly funded under the Australian system. The GP plays a key role in encouraging family members to attend for testing and helping explain the concept of 50% inheritance risk in first-degree relatives.

Differential diagnosis: when family history is the clinical question

Family history pattern	Likely hereditary syndrome
Multiple breast cancers in family, early onset	HBOC (BRCA1/2, PALB2)
Male breast cancer	BRCA2 (predominantly)
Triple-negative breast cancer ≤60	BRCA1
High-grade serous ovarian cancer	BRCA1/2
Young-onset CRC + endometrial cancer in family	Lynch syndrome
Hundreds of colonic adenomas	FAP or MAP
Sarcoma + brain tumour + breast in young family	Li-Fraumeni
Multiple endocrine tumours (parathyroid, pituitary, pancreatic)	MEN1
Medullary thyroid carcinoma	MEN2A or MEN2B
Renal tumours + cerebellar haemangioblastoma	Von Hippel-Lindau
Multiple primary melanomas in family	CDKN2A or BAP1
Mucocutaneous pigmentation + GI hamartomas	Peutz-Jeghers
Uveal melanoma + mesothelioma	BAP1
Diffuse-type gastric cancer + lobular breast	HDGC (CDH1)

B. Evidence appraisal — key interventions

CAPP2 — aspirin in Lynch syndrome: The CAPP2 randomised controlled trial enrolled 861 Lynch syndrome carriers to receive aspirin 600 mg/day or placebo. After a mean follow-up of 56 months, aspirin reduced colorectal cancer incidence by approximately 50% — a benefit that emerged several years after the intervention period, consistent with a long latency effect on adenoma-to-carcinoma progression. This is now incorporated into Lynch syndrome management recommendations. The optimal dose is under investigation in CAPP3; 600 mg/day is the evidence-based dose from CAPP2, but lower doses (100–300 mg/day) are being evaluated.

Risk-reducing mastectomy and RRSO: Observational cohort data consistently demonstrate that risk-reducing bilateral mastectomy reduces breast cancer incidence by approximately 95% in BRCA carriers, and that RRSO reduces ovarian/fallopian tube cancer risk by over 80% while also reducing breast cancer risk in BRCA1 carriers who undergo surgery before natural menopause. Both decisions are complex, informed, and shared — the timing relative to childbearing, the impact on menopausal symptoms, cardiovascular and bone health implications of premature menopause, psychological wellbeing, and body image all require careful multi-disciplinary counselling at the Family Cancer Clinic level.

Multi-gene panel vs single-gene testing: MSAC 1504 (2024) reflects strong evidence that multi-gene NGS panel testing is more cost-effective and clinically efficient than sequential single-gene testing. Identifying PALB2, ATM, CHEK2, or RAD51C/D pathogenic variants in patients who would previously have received only negative BRCA1/2 results opens additional surveillance and risk-reduction options. The panel does generate variants of uncertain significance (VUS) — variants where the clinical significance is not yet established — which require specialist counselling and do not trigger risk-reduction interventions.

Direct-to-consumer genetic testing: Products such as 23andMe test a limited number of known variants (for example, three Ashkenazi Jewish BRCA founder mutations) and do not perform full clinical-grade gene sequencing. A negative DTC result does not exclude a pathogenic variant. Patients with positive DTC results, or those who have used DTC testing and remain concerned about family history, should be referred to a Family Cancer Clinic for comprehensive clinical assessment.

Universal MMR/MSI screening of colorectal cancer: eviQ recommends universal immunohistochemistry for mismatch repair proteins (MLH1, MSH2, MSH6, PMS2) on all colorectal cancers, with BRAF V600E testing and MLH1 promoter methylation to distinguish sporadic MMR-deficiency from Lynch syndrome. This universal screening approach is increasingly adopted in AU pathology services and is the most efficient route to identifying Lynch syndrome probands.

C. Australian operations

MBS items

The following Medicare Benefits Schedule items are relevant to hereditary cancer syndrome management in general practice:

• GP consultation: items 23 / 36 / 44 — Level C or D appropriate for comprehensive family history-taking and genetics-related counselling.
• Germline HBOC testing: items 73296 / 73297 / 73298 for women with breast or ovarian cancer meeting eligibility criteria.
• Expanded panel testing (post-MSAC 1504, 2024): multi-gene panel for affected probands meeting criteria (BRCA1/2, PALB2, RAD51C/D, BRIP1, ATM, CHEK2, NF1, PTEN, STK11, TP53, CDH1, MMR genes).
• Lynch syndrome MMR gene testing: separately MBS-funded for eligible probands with young-onset CRC or MMR-deficient tumour.
• Cascade testing of relatives: publicly funded once proband’s variant is identified.
• Chronic disease management (GPCCMP): items 965 / 967 for coordinating allied-health care in patients with confirmed hereditary cancer syndrome.
• GP Mental Health Care Plan: items 2715 / 2717 for risk-related anxiety, depression, or adjustment difficulties.
• Telehealth: items 91890 / 91891 — Family Cancer Clinics increasingly offer telehealth counselling, particularly valuable for rural and remote Australians.
• ATSI Health Assessment: item 715.

PBS medications

• Aspirin (600 mg/day for Lynch syndrome) — PBS general-schedule pricing; also available OTC. Prescribe and document the indication in the patient record.
• Tamoxifen and aromatase inhibitors — PBS general schedule for breast cancer indications; Authority Required for chemoprevention in some cases.
• PARP inhibitors (olaparib, niraparib, rucaparib, talazoparib) — PBS Authority Required for BRCA-mutated ovarian, breast, prostate, and pancreatic cancers; oncologist-initiated.
• HPV vaccination and hepatitis B vaccination — National Immunisation Program schedule; relevant to cervical and liver cancer prevention in affected families.

Insurance considerations

The life insurance industry in Australia agreed to a voluntary moratorium in 2019, extended and expanded in 2024, under which insurers do not use genetic test results in underwriting life insurance policies up to specified cover amounts. However, protections for income protection insurance and total and permanent disability (TPD) insurance remain incomplete. Pre-test genetic counselling at the Family Cancer Clinic must address these implications, as a confirmed pathogenic variant may affect a patient’s ability to obtain these products at standard rates. Patients can access current information from the Australian Genetic Discrimination Project. GPs should document that insurance implications were discussed before any referral for genetic testing.

Referral pathways

• Routine: Family Cancer Clinic for any patient meeting eviQ criteria, including those with a new family cancer diagnosis that tips them into the referral threshold.
• Semi-urgent: new personal cancer diagnosis with hereditary red flag features — seek early FCC input to guide genetic testing of the proband and family.
• What to include in referral: three-generation pedigree; personal cancer history with pathology dates; prior genetic testing results; any tumour MMR/MSI testing results; current medications.

D. Australian operations — National Bowel Cancer Screening and Lynch

The National Bowel Cancer Screening Program (immunochemical faecal occult blood testing offered two-yearly from age 50) is not sufficient surveillance for Lynch syndrome carriers, who require full colonoscopy every one to two years from age 25. GPs should ensure Lynch-confirmed patients are formally excluded from relying on the population screening program and are enrolled in the FCC-coordinated colonoscopy program. A letter from the FCC to the patient outlining their surveillance plan is the primary document; the GP should maintain a copy in the patient’s file and review adherence at each annual review.

E. Special populations

Ashkenazi Jewish patients

BRCA1 and BRCA2 founder mutations (BRCA1 185delAG, BRCA1 5382insC, BRCA2 6174delT) occur in approximately 1 in 40 Ashkenazi Jewish individuals, compared with approximately 1 in 400 in the general population. Targeted founder mutation testing is available but comprehensive panel testing identifies additional variants beyond the three founders. Any Ashkenazi Jewish patient with a personal or family history of breast, ovarian, or pancreatic cancer should be referred to a Family Cancer Clinic regardless of the number of affected relatives.

Patients from Aboriginal and Torres Strait Islander communities

Population-level cancer genetics data in Aboriginal and Torres Strait Islander communities are limited, and cultural factors significantly affect participation in genetic testing programs. GPs should work in partnership with ACCHOs and cultural liaison workers when navigating family history discussions and referrals. Genetic counselling needs to be delivered in a culturally safe manner. The Closing the Gap PBS Co-payment applies for any PBS chemoprevention medicines for eligible patients. Family Cancer Clinics in some states have cultural safety training and Indigenous patient support pathways.

Patients with a new cancer diagnosis

When a patient is newly diagnosed with a cancer that may have hereditary features — for example, triple-negative breast cancer, young-onset colorectal cancer, or high-grade serous ovarian cancer — the treating oncology team will often initiate genetic testing. The GP should nonetheless flag the family history implications, encourage testing of relatives once a variant is identified, and provide psychosocial support during the genetic counselling process.

Children at risk

For children with a parent confirmed to carry FAP (APC), genetic testing is recommended from age 10–12 because colonic adenomatosis begins in adolescence. For MEN2A/B (RET), the timing of prophylactic thyroidectomy is guided by genotype-specific risk stratification and may occur in early childhood. For most adult-onset syndromes (BRCA, Lynch, Li-Fraumeni), genetic testing in childhood is deferred unless there is a childhood-onset cancer risk, as in Li-Fraumeni (adrenocortical carcinoma, paediatric brain tumours). Pre-implantation genetic diagnosis (PGD) is available for known pathogenic variants and is a reproductive option for variant carriers considering future pregnancy; access is via IVF centres with genetic testing capabilities.

When to escalate

In general practice, the escalation threshold for hereditary cancer syndromes is the identification of any red flag feature — at which point the patient should be referred to a Family Cancer Clinic rather than managed in the GP setting alone. Genetic counselling and testing require pre-test informed consent processes, variant interpretation by an accredited laboratory, and multidisciplinary risk-reduction planning that exceeds the general practice scope.

For a patient with a known syndrome who presents with a new symptom potentially consistent with a syndrome-related cancer (for example, a Lynch syndrome carrier with rectal bleeding or postmenopausal bleeding), expedite investigation and referral. Do not assume surveillance is providing complete protection — cancers can develop at intervals between scheduled procedures.

Safety-net all patients at elevated familial risk with explicit instructions: “Tell me or your Family Cancer Clinic if any relative is newly diagnosed with cancer, particularly at a young age, and keep your surveillance appointments — they exist because your risk is higher than average.”

What this article is and is not

This article is a clinical education resource for Australian-registered general practitioners, written by Dr Hoe Bing Lo (MBBS, FACRRM, AHPRA MED0001212640) and reflecting eviQ Cancer Genetics protocols, MSAC 1504 (2024), Cancer Council Australia guidance, CAPP2 Lancet 2020, and eTG as at the date of review.

This article does not constitute medical advice for patients. People concerned about a family history of cancer should speak with their GP and ask for a referral to a Family Cancer Clinic. Genetic test results must always be interpreted by a qualified genetic counsellor or clinical geneticist.

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Sources cited

• eviQ Cancer Genetics — Cancer Institute NSW
• Cancer Council Australia — Family history and genetic testing
• MSAC 1504 — Expanded inherited cancer panel testing (2024)
• eTG complete — Familial cancer
• RACGP — clinical resources
• NHMRC — Cancer genetics resources
• Burn J et al. CAPP2: aspirin and colorectal cancer in Lynch syndrome. Lancet 2020
• Villani A et al. Toronto surveillance protocol for Li-Fraumeni. Lancet Oncol 2016
• CanRisk / BOADICEA cancer risk calculator
• Inherited Cancers Australia
• Pink Hope — hereditary breast and ovarian cancer
• Lynch Syndrome International
• Australian Genetic Discrimination Project
• HealthDirect — cancer genetics information